Author Topic: CB750F2 .... silk purse from a sows ear.  (Read 4009 times)

Offline philward

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Re: CB750F2 .... silk purse from a sows ear.
« Reply #60 on: August 04, 2018, 04:37:29 PM »
There's an overflow that goes back to they rear crankcase but 2 more rear facing overflow pipes that exit right over the rear wheel - don't fancy just pipes!

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Offline SumpMagnet

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Re: CB750F2 .... silk purse from a sows ear.
« Reply #61 on: August 04, 2018, 08:07:04 PM »
@Philward
I will nip out tomorrow and measure the seperator on mine for you.
CB750F2 - in pieces
CB900F Hornet - the daily transport

Offline philward

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Re: CB750F2 .... silk purse from a sows ear.
« Reply #62 on: August 04, 2018, 08:42:13 PM »
Thanks
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Offline SumpMagnet

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Re: CB750F2 .... silk purse from a sows ear.
« Reply #63 on: August 06, 2018, 02:31:33 PM »
After slicing a chunk out of my hand, I have been out of action for the last few days and unable to do a lot.

The engine is still stranded in the frame like a beached whale, and there isn't much I can do about it for a few more days...so I have started turning to some of the smaller jobs that I can do.
Largely cleaning up, and assessing condition for some of hte other parts.

It does raised a big question as to the value of retaining some of the US spec parts and dubious add ons. Do they have any value at all?

High bars. Horrid shape, and so pulled back your wrists are 90 degrees from where nature says they are comfortable?
That seat....just look at it in the first few pics. The base is corroded down one side underneath, with a few areas thin enough to poke a stick through. I could pull off the cover and the foam and have a go at welding in some fresh sheet metal to rebuild it, but I can't see myself ever having a need for it in the shape it is. I mean..it has buttons down the middle for gods sake. Rivets in the pan hold the strings that keep the buttons in. If I want a stock seat, it is probably cheaper to buy a replacement than have this retrimmed with new foam and vinyl. Not to mention the time and effort to remove the rot.
The exhaust is proving a stubborn beast too. The stub of the rotted end pipe is resisting my efforts to remove it, and there looks to have been some loss of metal around the end of the header where it goes into the end pipe. It's just a pile of rust. I had to Dremel the bracket to remove it....and am now slicing metal again to get rid of the last bit. I am afraid it might not be worth it when I do get it off. But ...we got to try!

The 'cruiser pegs' on the front engine mounts are being used to ballast my bike cover and stop the wind blowing it off. Probably the most useful role they will ever perform. Another piece of metal I can't find the enthusiasm to E-Bay and will never have on any bike of mine.

So...what have we done:

Straightened the rear brake lever.
Stripped and cleaned up the seat hinge/catch
Removed the rear cowl from the seat and started a bit of patching work
Cleaned a few shiny bits
Started removing hte bearing races from the steering stem.

Not what I want to be doing...but small steps will have to do until I can do the bit bits again
CB750F2 - in pieces
CB900F Hornet - the daily transport

Offline paul G

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Re: CB750F2 .... silk purse from a sows ear.
« Reply #64 on: August 06, 2018, 02:41:35 PM »
Still got your sense of humour ;) keep up the good work as you say small steps until you can get back into it.
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Offline Spitfire

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Re: CB750F2 .... silk purse from a sows ear.
« Reply #65 on: August 07, 2018, 07:19:44 PM »
Was tidying my shelves today and found the vent trap from the F2 here's what it looks like.



Cheers

Dennis
1976 CB750F

1977 CB750F2

1964 BSA A65R

Offline philward

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Re: CB750F2 .... silk purse from a sows ear.
« Reply #66 on: August 07, 2018, 08:31:58 PM »
Dennis, is the vent trap surplus - if so let me know what you want for it
Phil
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Offline Spitfire

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Re: CB750F2 .... silk purse from a sows ear.
« Reply #67 on: August 08, 2018, 11:02:21 AM »
Sorry Phil it's probably the only part of an F2 that I have only one of.

Cheers

Dennis
1976 CB750F

1977 CB750F2

1964 BSA A65R

Offline philward

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Re: CB750F2 .... silk purse from a sows ear.
« Reply #68 on: August 08, 2018, 11:10:19 AM »
Thanks anyway Dennis

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Offline SumpMagnet

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Re: CB750F2 .... silk purse from a sows ear.
« Reply #69 on: August 10, 2018, 01:28:08 PM »
It's a funny old world.......

My last attempt at removing the engine had resulted in a weeks downtime on the project, a trip to casualty, and a fair bit of discomfort. But then things began to look up.

My hand was on the mend and whilst it still aches, had knitted together well enough for me to leave the dressings off and for it to start doing some work. Even better...another member on here, petermigreen, had offered to pop down and give me a hand...sorry.....couldn't help that one.... He had a couple of days off, and was looking for an excuse to enjoy the sunshine on his bike.

Only....the weather gods had another idea. After 3 months of drought, sun, scorching temperatures and rainfall that would not look out of place in the sahara....on the day we had chosen ( both of us off work... ) the heavens opened. It sluiced it down all day. No worries....reset, and go for Friday. Nope. The monsoon has carried on. I had a couple of hours this morning when it was still OK with the rain due around lunchtime.

So....I pulled the exhaust studs, undid 2 of the screws on the head breather cover....and applied the impact driver to the single screw that was already a bit chewed, and refused to shift despite an overnight soak with WD40. With the immortal good luck chant of 'shiftyabugger' upon my lips, it too gave up and undid. With the judicious use of a pair of axle stands, a trolley jack, and some zen buddhist meditation of teh miracles of geometry.....the end result was this....



and this....



The engine, of course, immediately tried to fall over, but with the aid of my youngest lad ( I say youngest...he's 18 and about a foot taller than me... ) the engine was rolled back the right way up. Straps went under the front, and onto the rear upper mounting bolt....and we manhandled ( man and boyhandled ??? ) the lump down the garden to the shed, in much the same way as our primitive ancesters shifted the rocks to make stonehenge.....

With that in the shed, we sacrificed a goat, and feasted ( well...no...I put the kettle on....)

The engine is in the shed....the frame is in the shed. The engine is sitting on a wooden cradle on the floor, as we simply could not get it up onto the bench with comfort....but it is where I can work on it. 5 minutes later......the heavens opened.

Thank you weather gods.

CB750F2 - in pieces
CB900F Hornet - the daily transport

Offline petermigreen

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Re: CB750F2 .... silk purse from a sows ear.
« Reply #70 on: August 10, 2018, 01:38:13 PM »
Yay, what a result.
All you've got to worry about now is getting it back in the frame without scratching all the new paint.  :o
Peter
1944 42WLA
1972 CB750K2 USA Candy Gold
1972 CB500K2 USA Candy Jet Green
1975 CB400F0 USA Ruby Red
1976 DT175C
1982 RD200F

Offline SumpMagnet

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Re: CB750F2 .... silk purse from a sows ear.
« Reply #71 on: August 10, 2018, 02:37:51 PM »
maybe I could cut the frame in half...lift it over...and weld it back..... just a bit of touching up needed then.
CB750F2 - in pieces
CB900F Hornet - the daily transport

Offline Spitfire

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Re: CB750F2 .... silk purse from a sows ear.
« Reply #72 on: August 10, 2018, 06:18:42 PM »
Now the fun begins !

Cheers

Dennis
1976 CB750F

1977 CB750F2

1964 BSA A65R

Offline SumpMagnet

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Re: CB750F2 .... silk purse from a sows ear.
« Reply #73 on: August 12, 2018, 05:59:56 PM »
Today the fun does indeed begin.....after a break yesterday for a flight in a Tiger Moth...and the chance to stand next to a Spitfire.....

So today, I started to delve into the top end of the engine.

Turning the motor over on the crank end nut did not feel brilliant in terms of compression. So....it might be the rings, or it might be the bores. Will find out.

Got the cam cover off with not too much bother, and only one screw head showed previous damage, and needed the impact driver. All the others released nicely. The two bolts under the breather cover were unmarked and perfect...so I wonder if anyone had ever undone those before. The others someone had tried to undo...
Under the cover, things were better than I was fearing. I always expect the worst when opening up something like this. It's like a Christmas present from an elderly relative. You have no idea what is going to be in there....but it's usually a disappointment. Rarely do you find what you hope for under the wrapping.

thankfully....this was not bad at all.



First plus point was the cleaar evidence of old oil residue over everything. I had feared dry....rusty cams. What I can see of the cams looks nice and shiny, with no evidence of scoring or wear marks. I have seen much worse.....including a set of Z650 cams that looked like a ploughed field.... 'was a good runner' according to the seller. He was an idiot...according to the buyer. The camchain still has good tension, and was oily...so there has been oil around these here parts.....

Worryingly....it has a full set of brand new plugs. Not a hint of carbon on them. I suspect someone was trying to get this thing to start, and found the electrical issues I was told about. They gave up clearly.



On the plus side....there was no evidence on any of the head bolts, cam bolts or cam carrier bolts to show someone had tried to undo any of them. That is reassuring...as it means I am not going to find someone elses foul up lurkling in here. Just wear and tear. Please go easy on the tear...

I have popped a slug of oil down eacy barrel and given it a few cranks by hand....then ligtly dropped hte plugs back in to keep the spiders out. That can sit over night to seep down the rings and coat the bores a bit. I also need to read up the manual a bit for the correct dismantling sequence. If there is a correct sequence for torquing down bolts..... I want to undo them in the reverse order. It may not be necessary...but I reckon it to be good practice. Plus I want to get an idea of how it all should fit together before I take it apart.....

tomorrow....I have an appointment with the Spanish Inquisitions chief torturer....sorry....the Dental Hygenist....so a bit of light reading will take my mind off the horrors to come
CB750F2 - in pieces
CB900F Hornet - the daily transport

Offline Trigger

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Re: CB750F2 .... silk purse from a sows ear.
« Reply #74 on: August 12, 2018, 06:08:36 PM »
That looks nice and clean inside, not even any burnt oil staining to the cam towers  :o