Honda-SOHC

SOHC.co.uk Forums => Project Board => Topic started by: Crispy on March 31, 2018, 04:39:09 PM

Title: 750 K1 project
Post by: Crispy on March 31, 2018, 04:39:09 PM
I acquired my valley green K1 a couple of months ago, its a US import in need of some attention. I have just started to spend some time on it as youve probably gathered from some of the posts i've already made. I'm really pleased to have joined this group because i have already received a lot of help and advice and found loads more information through reading other members posts and projects. Thanks.. its much appreciated.
The bike is now stripped and parts sorted,labelled and stored until ready to be dealt with. I thought i would make a start on the motor and I now have it cleaned and on a stand (thanks Julie!) but have been brought to a standstill on that front by the 3 breather cover screws on the rocker cover. All are seized solid. JIS impact driver wouldnt loosen them nor heat or penetrating oil, drilling the heads off made no difference, the cover still wouldnt come off.
I have after a week or so got the breather cover off and two of the screws out completely but one stubborn bu#8er will not come out and is holding the rocker cover on with it!...I will get it out eventually! :)
I have the forks stripped and ready to go for hard chroming, the seat is covered and just needs a couple of finishing touches (done while waiting for the penetrating oil to work its magic!).. Im really enjoying this!
Title: Re: 750 K1 project
Post by: Crispy on April 02, 2018, 11:12:13 AM
I've eventually managed to remove the rocker cover without causing any damage, and am about to start dismantling the camshaft and cylinder head, keeping my fingers crossed that I won't find anymore stubborn fasteners. I have the Honda workshop manual and have read a lot of threads but does anybody have any advice before I take the plunge dive in?  :-\
Cheers!
Title: Re: 750 K1 project
Post by: Nurse Julie on April 02, 2018, 12:09:01 PM
Slow, steady, methodical.
Title: Re: 750 K1 project
Post by: Spitfire on April 02, 2018, 12:17:28 PM
Not an expert at all, but I usually lay out the engine parts that I remove in the order that I remove them, so that they go back in the same place, before using any violence check thoroughly for hidden bolts, keep everything clean, you do not want even the tiniest of debris in those oilways. Take photos of stuff before you take it apart, pay paricular attention to cable and wiring runs, use plastic bags to keep parts in groups with bolts washers etc. Be patient and have fun

Cheers

Dennis
Title: Re: 750 K1 project
Post by: Crispy on April 02, 2018, 10:00:06 PM
Cheers guys, all tips and advice welcome!
Today I've managed to get the motor top end stripped down, no major traumas and without "using any violence" lol Dennis ! Plus I haven't damaged anything..as far as i know! ::)..  I need to take a few measurements now..pistons,rings bores etc, that will have to wait a while now..work does get in the way!
Ps. I've read threads re the cylinder studs but I didn't realise how slender and flexible they were until I've seen them today in the flesh for the first time, they don't inspire confidence do they? Do I take them out or not hmmm?  :-\
Title: Re: 750 K1 project
Post by: Crispy on April 09, 2018, 02:41:46 PM
Guys, Should these clutch release parts look Look this or are they worn?
Title: Re: 750 K1 project
Post by: Trigger on April 09, 2018, 02:44:38 PM
They look like that so that the ball bearings slide in and out easy. On reassemble, grease the parts and change the balls if rusty or not smooth  ;)
Title: Re: 750 K1 project
Post by: Crispy on April 09, 2018, 02:49:41 PM
Thanks very much Trigger, ... My balls aren't rusty  ::) so should be ok with a bit of grease!  ;D
Title: Re: 750 K1 project
Post by: Trigger on April 09, 2018, 02:50:03 PM
Cheers guys, all tips and advice welcome!
Today I've managed to get the motor top end stripped down, no major traumas and without "using any violence" lol Dennis ! Plus I haven't damaged anything..as far as i know! ::)..  I need to take a few measurements now..pistons,rings bores etc, that will have to wait a while now..work does get in the way!
Ps. I've read threads re the cylinder studs but I didn't realise how slender and flexible they were until I've seen them today in the flesh for the first time, they don't inspire confidence do they? Do I take them out or not hmmm?  :-\

Those head studs look good, leave them alone  ;) ;)
Title: Re: 750 K1 project
Post by: Trigger on April 09, 2018, 03:05:12 PM
I wish I had customers engines in for rebuilds that looked that good  ::)
Looks like it has never been apart before, what type of oil jets are in the head ? It should be the pepper pot ones  ;)
Title: Re: 750 K1 project
Post by: Crispy on April 09, 2018, 03:46:19 PM
I wish I had customers engines in for rebuilds that looked that good  ::)
Looks like it has never been apart before, what type of oil jets are in the head ? It should be the pepper pot ones  ;)

Now you're asking! I'll have to find them first. Will look shortly! I don't think it has been apart before....it's looking better than I'd hoped although I need to measure everything yet and see how much wear there is.
Title: Re: 750 K1 project
Post by: paul G on April 09, 2018, 03:48:55 PM
I wish I had customers engines in for rebuilds that looked that good  ::)
Looks like it has never been apart before, what type of oil jets are in the head ? It should be the pepper pot ones  ;)

Trigger,
               You might want to explaine the pepper pot as they do look more like a salt pot on the top  ;)
Title: Re: 750 K1 project
Post by: Crispy on April 09, 2018, 03:56:11 PM
This one?  Do they need to come out?
Title: Re: 750 K1 project
Post by: Nurse Julie on April 09, 2018, 04:40:12 PM
Look like salt pot on the top side but pepper pot on the underside if yours are these type. Like this

[attachimg=1]

Yes, need to come out to be cleaned thoroughly. It can be a  very difficult job to get them out, one usually comes out easier than the other. Sometimes have to almost wreck them to get them out and then re engineer to make good. No longer available OEM or pattern.
Title: Re: 750 K1 project
Post by: Crispy on April 09, 2018, 04:49:08 PM
Et Voila!  :). Good job you guys know what's What ! You had me worried then with talk of 're-engineering'  :o These two have come out quite easily...which is more than I can say for some the fasteners so far! Can't budge the exhaust stub screws !
Title: Re: 750 K1 project
Post by: Nurse Julie on April 09, 2018, 04:53:29 PM
Et Voila!  :). Good job you guys know what's What ! These two have come out quite easily...which is more than I can say for some the fasteners so far! Can't budge the exhaust stub screws !
Blimey, you are a very lucky chap. Graham would faint with shock if he had them come out that easy but, like he said previously, your engine looks a million dollars compared to some of the ones we get through here  :'( :'( :'(
Title: Re: 750 K1 project
Post by: Crispy on April 09, 2018, 05:03:39 PM
Yes I'm beginning to realise that it's not bad after seeing some of the project threads...still it's a big  but enjoyable learning curve for me ....and I've learned loads today...🙌
Title: Re: 750 K1 project
Post by: Bryanj on April 09, 2018, 05:29:29 PM
Big thing is all oilways scrupulously clean along with gasket surfaces, a tiny amount of gasket material in an oilway will wreck the top end
Title: Re: 750 K1 project
Post by: Trigger on April 09, 2018, 05:43:02 PM
Et Voila!  :). Good job you guys know what's What ! You had me worried then with talk of 're-engineering'  :o These two have come out quite easily...which is more than I can say for some the fasteners so far! Can't budge the exhaust stub screws !

How the hell did you get those out without grabbing hold of the nipple ?  Or have you flattened the nipple ?
 I have made so many special tools to get those out.
Title: Re: 750 K1 project
Post by: Crispy on April 09, 2018, 05:55:40 PM
Big thing is all oilways scrupulously clean along with gasket surfaces, a tiny amount of gasket material in an oilway will wreck the top end
Cheers Bryanj
After reading your post I've just spent a few minutes blowing air down all the holes in the cylinder head and seeing where it comes out ...to give me an idea of where the oil ways run...and to make sure they're clear. It is difficult to keep everything clean though, I power washed the motor before I started stripping it down but there's still dirt everywhere. I can now understand why some of you have separate clean and dirty workshops.
Title: Re: 750 K1 project
Post by: Crispy on April 09, 2018, 06:25:08 PM
Et Voila!  :). Good job you guys know what's What ! You had me worried then with talk of 're-engineering'  :o These two have come out quite easily...which is more than I can say for some the fasteners so far! Can't budge the exhaust stub screws !

How the hell did you get those out without grabbing hold of the nipple ?  Or have you flattened the nipple ?
 I have made so many special tools to get those out.

I think my nipples are ok! 😬
Although I did grab hold of them with a pair of long nose pliers! I didn't put too much pressure on them..gave them a waggle and out they popped!
Title: Re: 750 K1 project
Post by: Crispy on April 09, 2018, 06:45:22 PM
Finished my seat off today with the logo and strap, pleased with how that turned out and also butchered a spare socket to make a valve removal tool which worked really well. I know it's not a big deal but it was very satisfying to get them all out with it!  ::)
Title: Re: 750 K1 project
Post by: Crispy on April 09, 2018, 07:16:25 PM
Got another question...having removed the valves, there are only 4 valve stem seals ..on the inlet valves ..although the exploded parts diagram shows them on both inlet and exhaust.. Is this because it's an earlyish motor?
Title: Re: 750 K1 project
Post by: Nurse Julie on April 09, 2018, 07:27:24 PM
Yes, the early ones don't have exhaust valve seals.
Title: Re: 750 K1 project
Post by: Trigger on April 09, 2018, 07:34:08 PM
Et Voila!  :). Good job you guys know what's What ! You had me worried then with talk of 're-engineering'  :o These two have come out quite easily...which is more than I can say for some the fasteners so far! Can't budge the exhaust stub screws !

How the hell did you get those out without grabbing hold of the nipple ?  Or have you flattened the nipple ?
 I have made so many special tools to get those out.

I think my nipples are ok! 😬
Although I did grab hold of them with a pair of long nose pliers! I didn't put too much pressure on them..gave them a waggle and out they popped!

Those are in perfect shape, more evidence that that motor has never been apart before  ;) To clean the jets, soak in thinners for a couple of days and dig with a thin bit of wire (from a wire brush) before blowing out with a airline.
Title: Re: 750 K1 project
Post by: Crispy on April 09, 2018, 08:47:30 PM
Et Voila!  :). Good job you guys know what's What ! You had me worried then with talk of 're-engineering'  :o These two have come out quite easily...which is more than I can say for some the fasteners so far! Can't budge the exhaust stub screws !

How the hell did you get those out without grabbing hold of the nipple ?  Or have you flattened the nipple ?
 I have made so many special tools to get those out.

I think my nipples are ok! 😬
Although I did grab hold of them with a pair of long nose pliers! I didn't put too much pressure on them..gave them a waggle and out they popped!

Those are in perfect shape, more evidence that that motor has never been apart before  ;) To clean the jets, soak in thinners for a couple of days and dig with a thin bit of wire (from a wire brush) before blowing out with a airline.

👍
Title: Re: 750 K1 project
Post by: Crispy on April 15, 2018, 10:09:39 AM
I've measured my cylinders, pistons and ring gaps, (see pic)  Measurements seem to be only just within tolerance, out of round and taper seem ok. What do you think folks? ...will I be ok using the cylinders and Pistons as they are Just replacing the rings ?

Limit for cylinders is rebore if diameter is greater 61.1mm
Limit for piston is replace if diameter is less than 60.85mm

My measurements seem to be very close to these limits although they are within them.  :-\
Title: Re: 750 K1 project
Post by: Trigger on April 15, 2018, 10:17:10 AM
I've measured my cylinders, pistons and ring gaps, (see pic)  Measurements seem to be only just within tolerance, out of round and taper seem ok. What do you think folks? ...will I be ok using the cylinders and Pistons as they are Just replacing the rings ?

Limit for cylinders is rebore if diameter is greater 61.1mm
Limit for piston is replace if diameter is less than 60.85mm

My measurements seem to be very close to these limits although they are within them.  :-\

By your measuring, it looks like piston 2,3,4 won't fit the bore as the pistons are bigger  ;)
Title: Re: 750 K1 project
Post by: Crispy on April 15, 2018, 10:29:29 AM
🙄....damn!! I'll do them again!! 😂
Title: Re: 750 K1 project
Post by: Crispy on April 15, 2018, 10:45:43 AM
Ok here's another attempt..these are the averages of several readings....it's a long time since I've done any maths!! 😂

Just realised that the pistons are measured at the skirt...mine are very tight in  the bore of the cylinder at the top!
Title: Re: 750 K1 project
Post by: Trigger on April 15, 2018, 12:21:12 PM
That looks better. The skirts are very tight on a Honda.
Is there any lip at the top of the bores, pics please  ;)
Title: Re: 750 K1 project
Post by: Crispy on April 15, 2018, 01:13:17 PM
That looks better. The skirts are very tight on a Honda.
Is there any lip at the top of the bores, pics please  ;)

Yes I can feel a lip.
Title: Re: 750 K1 project
Post by: Trigger on April 15, 2018, 01:25:05 PM
OK, they need to be honed out until the lip is visible no more. Then you can get a true measurement  ;)
I know what all the books say to the max spec but, when this engine was new, the piston to bore clearance was tight and when I mean tight, less than 1 thou. 
Title: Re: 750 K1 project
Post by: Crispy on April 15, 2018, 02:01:30 PM
OK, they need to be honed out until the lip is visible no more. Then you can get a true measurement  ;)
I know what all the books say to the max spec but, when this engine was new, the piston to bore clearance was tight and when I mean tight, less than 1 thou.

Cheers Trigger, I'll see about getting that done ...👍
Title: Re: 750 K1 project
Post by: Crispy on April 16, 2018, 09:01:07 PM
Checked the valves over tonight..looks like they and the guides will need replacing they failed on both the valve guide clearance and vertical run out measurements...by a large margin! doh! 😕  On a more positive note the springs are ok! 😊
Title: Re: 750 K1 project
Post by: Nurse Julie on April 16, 2018, 09:06:12 PM
Loving your upside down pics, is it a Derbyshire thing? 😀😀😀
Title: Re: 750 K1 project
Post by: Crispy on April 16, 2018, 09:10:52 PM
Loving your upside down pics, is it a Derbyshire thing? 😀😀😀

Haha! Don't know why they appear upside down! They turn the right way up when you view them ! 🤔😂
Title: Re: 750 K1 project
Post by: Trigger on April 16, 2018, 09:12:48 PM
Checked the valves over tonight..looks like they and the guides will need replacing they failed on both the valve guide clearance and vertical run out measurements...by a large margin! doh! 😕  On a more positive note the springs are ok! 😊

The valve face is pitted, this is down to the valve clearance being too tight. These will need re facing  ;)
Title: Re: 750 K1 project
Post by: Crispy on April 16, 2018, 09:28:02 PM
Checked the valves over tonight..looks like they and the guides will need replacing they failed on both the valve guide clearance and vertical run out measurements...by a large margin! doh! 😕  On a more positive note the springs are ok! 😊
u

The valve face is pitted, this is down to the valve clearance being too tight. These will need re facing  ;)

The valve seats look ok tho! 😬
Title: Re: 750 K1 project
Post by: Trigger on April 16, 2018, 10:07:34 PM
They will clean up but, if you have new valve guides fitted. The head needs to be about 300c in a oven and the guides need to be frozen to make fitting easy. The heat distorts the head a little so, a head skim and valve seats re ground. Not Cut  ;)
Title: Re: 750 K1 project
Post by: Crispy on April 17, 2018, 08:12:25 AM
I've seen threads re pre honed guides on the US site... What's the score with these..do these do away with the need for reaming after fitting?  opinion seems to be divided?
Title: Re: 750 K1 project
Post by: Trigger on April 17, 2018, 08:39:22 AM
There is plug and play valve guilds on the market for modern heads. They come as a set, valves and guilds, even today there are valves on the market that are Teflon coated so, you can't even lap them in. This is all apart of the throwaway society and making engineers in to fitters.
On these old girls, you should use the upgraded valve guides, that have oil seals on all. One of the best I have found are sets from Yamiya. These still need to be reamed with a Honda tool to spec.
Title: Re: 750 K1 project
Post by: Crispy on April 17, 2018, 06:46:51 PM
Ok 👍  Thanks for that...ill probably end up farming that out! I've never reamed anything and probably not a good idea to start now! 😬
Title: Re: 750 K1 project
Post by: Trigger on April 17, 2018, 07:47:45 PM
Just make sure that they know about old Honda's and have the right tooling. I spend half my day correcting other engineers work  >:( And if they mention that they do brit bikes, RUN  ;)
Title: Re: 750 K1 project
Post by: Crispy on April 18, 2018, 07:11:20 PM
😂👍
Title: Re: 750 K1 project
Post by: Crispy on May 07, 2018, 05:53:10 PM
Damn!! Took the sump off  today and found these two pieces lying there...don't know where they've come from yet but it's a bit of a dampener on such a nice day!
Title: Re: 750 K1 project
Post by: Nurse Julie on May 07, 2018, 06:04:36 PM
Don't panic yet, they look like they are pieces of the internal casings.....i could be wrong of course but they look mighty familiar. As you strip the engine fully, just keep your eyes open for some bits missing around the mouldings on the casings.
Title: Re: 750 K1 project
Post by: Crispy on May 07, 2018, 06:15:00 PM
I have the engine in the stand, would you take it out and turn it upside down to split it or just carry on with it in the stand?
Title: Re: 750 K1 project
Post by: Crispy on May 07, 2018, 06:52:33 PM
Ok belay that last question..its out and upside down! 🙄
Title: Re: 750 K1 project
Post by: Crispy on May 07, 2018, 07:11:59 PM
Found the damaged area..right beside the primary chain tensioner. This critical?
Title: Re: 750 K1 project
Post by: Nurse Julie on May 07, 2018, 07:19:21 PM
I will ask Trig if he advises repairing or just leaving, I will report back.
Title: Re: 750 K1 project
Post by: Crispy on May 07, 2018, 07:29:25 PM
Thanks Julie! 👍
Title: Re: 750 K1 project
Post by: Nurse Julie on May 07, 2018, 08:06:33 PM
Thanks Julie! 👍
Trig says he would leave as is. It most probably would have been damaged by the cam chain flapping around at some stage in the engines life.
Title: Re: 750 K1 project
Post by: K2-K6 on May 07, 2018, 08:30:02 PM
If it's been apart before then it may have had the crank rotated with the cam not in place and the chain bunched down round the crank.

It doesn't look structural,  but I think they use things like that for "windage" to get oil to separate from the crank at high rpm and force it to drop back into the sump rather than getting a mass of oil rotating with the crank assembly.
Title: Re: 750 K1 project
Post by: Crispy on May 07, 2018, 08:47:31 PM
Thanks folks..👍
Title: Re: 750 K1 project
Post by: Trigger on May 07, 2018, 09:10:58 PM
Normal on a 750  ;)
Title: Re: 750 K1 project
Post by: Crispy on May 07, 2018, 09:35:27 PM
Phew was worried for a while.....👍
Title: Re: 750 K1 project
Post by: Trigger on May 07, 2018, 10:54:50 PM
Phew was worried for a while.....👍

When fitting a new cam chain, always use the upgraded DID  ;)
Title: Re: 750 K1 project
Post by: Crispy on May 08, 2018, 11:33:26 AM
Phew was worried for a while.....👍

When fitting a new cam chain, always use the upgraded DID  ;)
👍 Will do..thanks.

Going to check the main bearings for wear next...for the K1 is the red plastigauge in the range 0.025-0.175mm the one to get? Just double checking, 🤔
Title: Re: 750 K1 project
Post by: Tomb on May 09, 2018, 01:42:05 PM
Just make sure that they know about old Honda's and have the right tooling. I spend half my day correcting other engineers work  >:( And if they mention that they do brit bikes, RUN  ;)

Hahahaha yep I know this feeling, I have the "special" reamer, and make my own guides, and do Brit bikes (run!!) but also do old Hondas, Yamahas, Suzukis. Back when I did engineering work for folk I'd get a lot of work repairing local bike shops "engineering work".

Old Brit bike work on guides usually consisted of making bigger outside diameter guides as they had come loose in the head and worn the head, or knurling standard guides. I'd always make them a really tight fit to prevent it happening again, this would usually end up nipping the guide making the stem tight and reaming needed.
Title: Re: 750 K1 project
Post by: Crispy on May 14, 2018, 07:07:12 PM
Not checked my main bearings yet..still waiting for some plastigauge to arrive but judging by the wear and tear so far I'm expecting to have to put new ones in..so have been getting my head around the method of selecting the bearings this afternoon...not straightforward..like go out and buy a 6304 bearing is it?  Think I've Sussed  it....written them down below...any tips on where is the best place to get them if needed, also need to get full gasket , oil seals and o ring set?

Ps the upside down picture thing is something to do with my iPad, only occurs with pics taken with that...nobody else suffer from this?
Title: Re: 750 K1 project
Post by: Crispy on May 15, 2018, 07:32:28 AM
Just realised David Silvers has the bearings..thought they would be harder to find 🙄
Title: Re: 750 K1 project
Post by: Crispy on May 20, 2018, 05:17:24 PM
Measured the bearing clearances today...I'm thinking that these bearings will be ok  to re-use....I get a clearance of 0.050mm and the limit according to the manual is 0.080mm....However the manual also states that the standard clearance should be 0.02 to 0 046mm. Should I replace them anyway?
Title: Re: 750 K1 project
Post by: Trigger on May 20, 2018, 07:05:14 PM
To get that reading, have you torqued the crank up.
Bearings can be a bit funny, some of the gearbox bearings are under licence to Honda only.

Title: Re: 750 K1 project
Post by: Crispy on May 20, 2018, 07:18:19 PM
Yes..torqued it up as per the manual!
Title: Re: 750 K1 project
Post by: Trigger on May 20, 2018, 07:24:06 PM
Yes..torqued it up as per the manual!

Well, your plasti strip is a lot cleaner than mine  ;D ;D
Title: Re: 750 K1 project
Post by: Crispy on May 20, 2018, 07:29:05 PM
Well I've only used it once!... Bet yours has been put to more frequent use!
Title: Re: 750 K1 project
Post by: Trigger on May 20, 2018, 07:32:30 PM
I would go with those shells. Is the oil pump apart yet ? If the oil pump is at full pressure, the shells are fine.
Title: Re: 750 K1 project
Post by: Crispy on May 20, 2018, 07:39:47 PM
Cool ...No..I haven't touched the pump yet 😬  Will do at some point though !
I'll also repeat the plastigauge measurements a couple more times just to see if I can repeat the same results.
Title: Re: 750 K1 project
Post by: Crispy on June 03, 2018, 08:14:32 PM
Engine cases painted and cured, I can now begin to re assemble the engine.  After reading older threads I'm thinking I will get the Vesrah gasket set and Honda head gasket, unless anyone has any other advice.? I am also replacing the primary and cam chains, again any advice re primary chains ? Getting the upgraded did chain ....part number ....219FTH 94LE ..which I've just spotted on another recent thread... Cheers Trigger 👍
Title: Re: 750 K1 project
Post by: Trigger on June 03, 2018, 09:03:13 PM
Looks nice, what paint was used ? Use the STD primary chains. Vesrah are the best available.  Not sure if anyone in the UK does the upgraded cam chains, seems to be a lot of old stock ones floating about. If you get stuck for one, I can supply you one  ;)
Title: Re: 750 K1 project
Post by: Crispy on June 03, 2018, 10:20:12 PM
Cheers Trigger,
Used Simoniz VHT31C engine enamel, may be in touch re cam chain! 👍
Title: Re: 750 K1 project
Post by: Crispy on June 08, 2018, 06:51:09 PM
Got some nice shiny fork bits back from Philpotts today! 😊 Here are a few before and after pics..
Title: Re: 750 K1 project
Post by: Jamesh_sussex on June 08, 2018, 07:13:03 PM
Lovely work from Philpotts there..
Title: Re: 750 K1 project
Post by: Nurse Julie on June 08, 2018, 07:45:23 PM
Lovely shiney blingy bits there. Very nice. Did they polish the fork lowers you?
Title: Re: 750 K1 project
Post by: Crispy on June 08, 2018, 08:00:04 PM
Lovely shiney blingy bits there. Very nice. Did they polish the fork lowers you?

Yes, although they farm it out to someone else. It's the first time I've had anything polished I usually do it myself but they've done a much better job than I could have. One of the fork lowers had some deep marks in which although they haven't come out fully are nowhere near as bad.
Title: Re: 750 K1 project
Post by: Crispy on June 08, 2018, 08:02:22 PM
Lovely work from Philpotts there..

I agree, I was concerned about the depth of the corrosion but they reassured me, apparently in all the years they've been rechroming pitted forks they have only had a handful that were beyond repair.
The fork top nuts have come out really well, they were really chewed up and marked...look new now!
Title: Re: 750 K1 project
Post by: Crispy on July 16, 2018, 10:03:53 AM
after a bit of a delay in things due to unforeseen circumstances,  I have got my cam and primary chains ,gaskets and seals sorted...I'm probably using the existing bearings as they seem OK...im just unsure about the chain tensioners. Should I just replace them as a matter of course?  The wheels and guide seem to be in OK condition but they are 47 years old??
Title: Re: 750 K1 project
Post by: Nurse Julie on July 16, 2018, 10:13:04 AM
They may look ok but the rubber bits will probably be hard and brittle so best to change them as you are there.
Title: Re: 750 K1 project
Post by: Crispy on July 16, 2018, 10:23:20 AM
Yes..I suppose I answered my own question there...thanks for the reply 👍
Title: Re: 750 K1 project
Post by: Crispy on July 19, 2018, 10:08:40 PM
Made a start tonight on reassembling the motor...got the crank,mainshaft and final drive assembled in the top case. It is probably going to be several months before it (hopefully) runs..i am using graphogen and engine oil as lubricants? It's a great feeling when parts start going back together!...so far anyway!  :)
Title: Re: 750 K1 project
Post by: Crispy on July 21, 2018, 08:59:17 PM
Today I got most of the engine internals fitted into the crankcases, I'm now waiting for a few o rings to arrive before closing the cases up..what are your thoughts folks on the oil catch tray that directs oil onto the drive sprocket? ...I've read that it can be quite messy...Can it be left out?
Title: Re: 750 K1 project
Post by: Green1 on July 21, 2018, 09:17:18 PM
Mines still there turned down to its minimum.
It does get oil on the back wheel but I can live with that as I do give the bike a bit of stick. In the 5 years and almost ten thousand miles I have never needed to adjust the chain  :)

Oil on the rear wheel is a good thing in my eyes it keeps the chrome nice
By the time the rear wheel is black the bike needs cleaning anyway.
Title: Re: 750 K1 project
Post by: Trigger on July 21, 2018, 09:46:32 PM
I always fit the oil plate and cap off the oil outlet with a O'ring  ;)
Title: Re: 750 K1 project
Post by: Green1 on July 21, 2018, 09:53:20 PM
Why do that Graham there not your bikes to clean in the future.
Think of all those pennies you could have saved.  ;D ;D
Title: Re: 750 K1 project
Post by: Crispy on July 22, 2018, 07:02:35 AM
Thanks guys...fitted it is then 👍
Title: Re: 750 K1 project
Post by: Crispy on July 22, 2018, 03:28:52 PM
I'm about to fit the cases together...got new o ring on the gallery feed to front of cases and 2 locating dowels in place on 1 on each side, new primary chain tensioner in,loctited and torqued..all surfaces cleaned, using Honda bond....any advice ..tips...warnings before I go for it?  :-\
Title: Re: 750 K1 project
Post by: Nurse Julie on July 22, 2018, 03:33:18 PM
Maybe a dry run first, just to check it is all going to go together ok.
Title: Re: 750 K1 project
Post by: Trigger on July 22, 2018, 03:35:43 PM
I'm about to fit the cases together...got new o ring on the gallery feed to front of cases and 2 locating dowels in place on 1 on each side, new primary chain tensioner in,loctited and torqued..all surfaces cleaned, using Honda bond....any advice ..tips...warnings before I go for it?  :-\

You need to put the crank seal on first  ;)

And final drive seal  ;) I will keep looking  ;D ;D
Title: Re: 750 K1 project
Post by: Crispy on July 22, 2018, 03:38:21 PM
Great...good job I asked! Thanks 👍.....I need to get out of the garage for a while tho..I used lacquer thinners to clean all the surfaces..I'm getting a bit high! 😂
Title: Re: 750 K1 project
Post by: Trigger on July 22, 2018, 03:50:00 PM
Can't see if you have the roll pin fitted and are all the half rings in ?

Have you done a dry run, to make sure all gears select .
Title: Re: 750 K1 project
Post by: Crispy on July 22, 2018, 04:44:08 PM
Yes..I have the three half rings and the roll pin that holds the kickstart shaft...crank seal and final drive oil seals are in now...trial fitting ok ..but I'll do it again and try the gear shift this time! 🙄
Title: Re: 750 K1 project
Post by: Crispy on July 22, 2018, 04:59:58 PM
Woohoo!....I can get 5 gears 😀
Title: Re: 750 K1 project
Post by: Nurse Julie on July 22, 2018, 05:05:21 PM
Woohoo!....I can get 5 gears 😀
👍👍👍👍👍
Title: Re: 750 K1 project
Post by: Crispy on July 22, 2018, 06:11:58 PM
 Bottom half back together, with Julie & Triggers timely help and advice, 🙌 thanks so much...having the knowledge of you guys available is so invaluable...got to get the top end sorted now but I'm pleased to get this bit done before I forgot where everything went! 💪
Title: Re: 750 K1 project
Post by: paul G on July 22, 2018, 06:58:39 PM
Lookin good. Painting my cases tomorrow  :)
Title: Re: 750 K1 project
Post by: Rob62 on July 22, 2018, 09:26:24 PM
Yeah looks really nice... its better if you can split the cases for painting. Mine was painted without splitting, as the motor internals seemed ok so a shame to split, but the painting looks betterr on yours.
Title: Re: 750 K1 project
Post by: Crispy on July 22, 2018, 10:11:26 PM
Cheers Guys, it's also easier to get it in the oven for curing 😉
Title: Re: 750 K1 project
Post by: Trigger on July 22, 2018, 10:27:21 PM
Looks like everyone is building K1's. I will have this one finished by the end of the week  ;)
Title: Re: 750 K1 project
Post by: Crispy on July 22, 2018, 10:58:32 PM
Nice one..just noticed on your lower case, the large round section has a securing clamp on it which mine doesn't have. It has the post for the bolt but it is undrilled. I assume some have it and others don't ?
Title: Re: 750 K1 project
Post by: Trigger on July 22, 2018, 11:04:51 PM
Nice one..just noticed on your lower case, the large round section has a securing clamp on it which mine doesn't have. It has the post for the bolt but it is undrilled. I assume some have it and others don't ?

That's because it is a it is a early K1 and yours is later  ;) Yours also has M6 flanged engine bolts and the one i am doing is the non flanged type. The oil bungs on the early's have a 17 AF and all later units were fitted with 14 AF.
Title: Re: 750 K1 project
Post by: Crispy on July 23, 2018, 07:39:23 AM
Nice one..just noticed on your lower case, the large round section has a securing clamp on it which mine doesn't have. It has the post for the bolt but it is undrilled. I assume some have it and others don't ?

That's because it is a it is a early K1 and yours is later  ;) Yours also has M6 flanged engine bolts and the one i am doing is the non flanged type. The oil bungs on the early's have a 17 AF and all later units were fitted with 14 AF.
Cheers Trigger...I must be turning into some sort of anorak! ...I find all these little differences/changes quite fascinating!  😬
Title: Re: 750 K1 project
Post by: Trigger on July 23, 2018, 09:19:38 AM
I would not say that it is being a anorak, it is just knowing the history of your bike.
The K1 was fitted with two different types of crank cases fitted. The early K1's had the crank cases used from the K0's  ( with slight changes in the castings ) and moved on to the later cases, which were used on some of the K2's.
The engine evolved over the years with 3 different types of oil pumps, 3 different clutch baskets, 2 different selector drums and so on. I don't need to see a engine numbers to know what year it is  :o Or if it has the wrong barrels or head fitted for that year. I have never found anyone that has wrote a book on all the correct detailing of the CB750K engines.
 
 
Title: Re: 750 K1 project
Post by: paul G on July 23, 2018, 01:19:47 PM
Maybe it's time you started Graham ;)
Title: Re: 750 K1 project
Post by: Trigger on July 23, 2018, 11:22:34 PM
Maybe it's time you started Graham ;)

Books Paul, i can't even be bothered to read one, never mind write one. Never seem to have time with members asking questions and looking for parts all day  ;D ;D ;D
Title: Re: 750 K1 project
Post by: Crispy on July 24, 2018, 10:02:43 PM
I would not say that it is being a anorak, it is just knowing the history of your bike.
The K1 was fitted with two different types of crank cases fitted. The early K1's had the crank cases used from the K0's  ( with slight changes in the castings ) and moved on to the later cases, which were used on some of the K2's.
The engine evolved over the years with 3 different types of oil pumps, 3 different clutch baskets, 2 different selector drums and so on. I don't need to see a engine numbers to know what year it is  :o Or if it has the wrong barrels or head fitted for that year. I have never found anyone that has wrote a book on all the correct detailing of the CB750K engines.

You can't beat knowledge gained by actually working on these engines over a lifetime....or practical experience in any job...and a good job for us that you and others are willing to share it! 👍
Title: Re: 750 K1 project
Post by: paul G on July 24, 2018, 10:31:00 PM
Maybe it's time you started Graham ;)

Books Paul, i can't even be bothered to read one, never mind write one. Never seem to have time with members asking questions and looking for parts all day  ;D ;D ;D
Who me  ;D ;D ;)
Title: Re: 750 K1 project
Post by: Nurse Julie on July 24, 2018, 10:37:03 PM
Maybe it's time you started Graham ;)

Books Paul, i can't even be bothered to read one, never mind write one. Never seem to have time with members asking questions and looking for parts all day  ;D ;D ;D
Who me  ;D ;D ;)
Trigs not pointing any fingers Paul but..........👉 👉 👉 👉 👉😊😊😊
Title: Re: 750 K1 project
Post by: Crispy on July 15, 2019, 06:13:42 PM
I've not posted anything on this thread for some time, things have progressed slowly but my motor , now Trigger has sorted the top end out for me,  is now ready to be fitted into the frame. Wheels are done just waiting for tyres, zinc plating done, chrome plating done, powder coating done. Left to do is paintwork, find a few parts that were missing or beyond repair and begin saving up for a full exhaust system, oh and probably replace most of the rubber parts that are rock hard. Things are beginning to get exciting, should have a rolling chassis soon!
Title: Re: 750 K1 project
Post by: Nurse Julie on July 15, 2019, 06:32:18 PM
Looking fantastic Mick.
Title: Re: 750 K1 project
Post by: rozabikes on July 15, 2019, 06:46:57 PM
I've not posted anything on this thread for some time, things have progressed slowly but my motor , now Trigger has sorted the top end out for me,  is now ready to be fitted into the frame. Wheels are done just waiting for tyres, zinc plating done, chrome plating done, powder coating done. Left to do is paintwork, find a few parts that were missing or beyond repair and begin saving up for a full exhaust system, oh and probably replace most of the rubber parts that are rock hard. Things are beginning to get exciting, should have a rolling chassis soon!
That's impressive mate, well done. My parts that I collected from T and J with yours on the same day are still on my bench untouched (but wrapped carefully to stop dust and dirt Trig!!). You have too much time on your hands!! :P
Title: Re: 750 K1 project
Post by: Laverda120 on July 15, 2019, 07:45:52 PM
Looking fantastic Mick. Real engine bling going on there!
I must retrieve my 750 motor from its den in Glasgow and get it over to Trigger for his magic touch👍.
Title: Re: 750 K1 project
Post by: royhall on July 15, 2019, 07:49:25 PM
Don't they look great when everything is painted and polished. Tends to hide the amount of effort it takes to get to that point though. Anyone that hasn't done it before is usually amazed at the cost and hours it takes. Many just become adandoned projects. Top job there, looking forward to seeing the rest of the bike.

Sent from my Pixel 3a XL using Tapatalk

Title: Re: 750 K1 project
Post by: Crispy on July 15, 2019, 08:49:15 PM
Thanks all for the kind words, wouldn't have got this far without the Help &  encouragement of the people on this forum  :)
Title: Re: 750 K1 project
Post by: Crispy on July 15, 2019, 08:52:52 PM
Don't they look great when everything is painted and polished. Tends to hide the amount of effort it takes to get to that point though. Anyone that hasn't done it before is usually amazed at the cost and hours it takes. Many just become adandoned projects. Top job there, looking forward to seeing the rest of the bike.

Sent from my Pixel 3a XL using Tapatalk

Thanks ! I can definitely understand why some become abandoned projects, unless as you say you've done it before then the time,effort and cost can come as a bit of a shock!
Title: Re: 750 K1 project
Post by: Green1 on July 15, 2019, 08:55:21 PM
Looking smart. I would love to spend more time on mine
Don't go green on the paintwork its to common and overrated  ;D
Title: Re: 750 K1 project
Post by: Crispy on August 11, 2019, 08:36:34 AM
Got the motor in to the frame now with my wife's help! Wheels are on so I can move it around as things are a bit tight now in my garage. The eagle eyed amongst you may spot that I have the front axle nut on the wrong way round in the picture (now corrected). The clocks were refurbished for me by Peter Kent  and Graham (Trigger) sorted out the motors top end. Thanks for all the help & advice so far, I'm pretty sure I'll be asking a few more questions before its finished, still a long way to go but it's looking like a motorcycle again now!
Title: Re: 750 K1 project
Post by: Crispy on August 11, 2019, 08:41:09 AM
Looking smart. I would love to spend more time on mine
Don't go green on the paintwork its to common and overrated  ;D
thanks, I'm not sure what colour I'll do the paintwork, at the moment I'm thinking to stay with Valley Green  but I'm tempted to go Candy Gold, I may just have to get another 750 so I can have one of each! :)
Title: Re: 750 K1 project
Post by: Nurse Julie on August 11, 2019, 09:01:30 AM
Great progress Mick.
Title: Re: 750 K1 project
Post by: Laverda120 on August 11, 2019, 12:10:26 PM
Looking fantastic Mick, not long to go before it's on the road.
Title: Re: 750 K1 project
Post by: Jamesh_sussex on August 11, 2019, 12:44:48 PM
Great progress - looking awesome. Keep the pics coming...
Title: Re: 750 K1 project
Post by: paul G on August 12, 2019, 08:09:24 AM
Coming along nicely Mick  :D
Title: Re: 750 K1 project
Post by: Crispy on August 12, 2019, 10:44:34 AM
Thanks all, I'm not expecting to get it on the road soon though, still missing quite a few parts  :o. I've  set myself a target of getting it ready for the next Crich show, if i manage it before then that will be a bonus.
I'm sorting the wiring out at the moment, trying to get it all in place and working while the frame is relatively bare, I'm not sure about the rectifier it looks a bit battered and the rubber surround to it has perished but hey ho! overcoming these little problems is one of the joys of restoring these old bikes. :)
Next problem to sort is an oil tank leaking from the base of one of the hose connections where it enters the tank, I'm going to try and get it brazed I think, anyone else had similar leak to sort?
Title: Re: 750 K1 project
Post by: Trigger on August 12, 2019, 09:16:16 PM
These were brazed from the factory. You will have to get all the paint off and make sure the tank is free from rust on the inside.
Title: Re: 750 K1 project
Post by: Crispy on August 25, 2019, 02:12:40 PM
Made a bit more progress today, got the Carburettors reassembled, everything seemed to go back together ok, good job I took loads of pics and notes!  :). here's before and after pics.
Title: Re: 750 K1 project
Post by: Nurse Julie on August 25, 2019, 06:01:14 PM
They have come up fantastic Mick, great job 👍👍👍
Title: Re: 750 K1 project
Post by: Andrew-S on August 25, 2019, 06:08:34 PM
Carbs look great, it may be one of the jobs I'll have to tackle on my K1.
Title: Re: 750 K1 project
Post by: Crispy on September 09, 2019, 07:52:49 AM
Pleased to report that I've had the oil tank repaired, I've painted it and it's now fitted to the bike along with whatever else I have that is ready to bolt on. I need to sort a brake out next as the bike is getting difficult to stop when I roll it back into the garage from my hill of a drive! :o Can anyone enlighten me as to how the oil tank works? In particular what does the pipe connected to the crank case do? Is it just a breather?   Thanks!  :)
Title: Re: 750 K1 project
Post by: SumpMagnet on September 09, 2019, 06:07:32 PM
Looking much shinier than my efforts :)

Not sure about the K1...but my F2 had a complex arrangement of pipes coming off the crankcase, through a catch tank bolted to the bottom of the battery box.
It wasn't connected to teh oil tank...the oil tank had a breather/overflow pipe running from the top back side of teh filler cap...straight down to the deck.

Now....that may not be correct...but it's how mine was when I got it

Title: Re: 750 K1 project
Post by: K2-K6 on September 09, 2019, 07:26:17 PM
The F2 came in the era of emmisions and trying to avoid output to atmosphere.  They effectively collect any oil suspended in air (smoke to most of us)  and seperate it at the air filter contraption to burn any contaminant by drawing in through intakes.

The early tanks vent to air from the top generally,  they have a built in air oil separator inside the tank that splits oil vapour to drip back into oil supply,  with air going out to ground.  This is from description in KO manual,  you'd have to look at later manuals to see your K model.

They have to vent both tank and crankcase,  ultimately to atmosphere, to prevent overpressure in engine.

Sealed completely, it'll try to push oil out of oil seals etc.  Also interferes with dry sump system on 750 as you don't need either vacuum or pressure exerting against oil pump operation.
Title: Re: 750 K1 project
Post by: Crispy on September 09, 2019, 10:28:51 PM

The early tanks vent to air from the top generally,  they have a built in air oil separator inside the tank that splits oil vapour to drip back into oil supply,  with air going out to ground.  This is from description in KO manual,  you'd have to look at later manuals to see your K model.

They have to vent both tank and crankcase,  ultimately to atmosphere, to prevent overpressure in engine.

Sealed completely, it'll try to push oil out of oil seals etc.  Also interferes with dry sump system on 750 as you don't need either vacuum or pressure exerting against oil pump operation.

Thanks, I understand what it's doing now, mine has the built in separator inside the tank, which as you say vents to ground from the top, the crankcase connects to the bottom.

Title: Re: 750 K1 project
Post by: Green1 on September 12, 2019, 09:44:19 PM
looking great Mick fancy having a crack at mine when your done?   :D
Title: Re: 750 K1 project
Post by: Crispy on September 13, 2019, 07:13:32 AM
looking great Mick fancy having a crack at mine when your done?   :D
Cheers Mick, I'm pleased with how it looks but the acid test will be when I come to eventually try and start it it!  :o I might have to work on other peoples bikes at some point! I don't think I could afford another one!  ;D
Title: Re: 750 K1 project
Post by: Crispy on September 13, 2019, 03:59:41 PM
Well having connected the oil tank up I started to put some oil in It Only to find it pouring out onto the bike and floor! Damn! On removing it and having a look,  I found that the rear oil hose had broken at the tank connection. I suppose better now than later when it's finished!  I know These are not cheap!  :-\ don't suppose I should trust the one that's left!
Title: Re: 750 K1 project
Post by: Green1 on September 13, 2019, 04:28:31 PM
I would risk keeping the other hose and then regret it as having one new one old would bug me.