Honda-SOHC
SOHC.co.uk Forums => CB750 => Topic started by: Johnny4428 on August 24, 2021, 07:18:13 AM
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Waiting for a new set of screws from DSS for transmission cover, apart from that she is ready for installing. Might run it before it goes in the frame. And rubber pucks to be fitted.
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Remove the exhaust flanges off as, this makes it easier to get in the frame and you won't scratch it ;)
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Will do Trigger! Cheers.
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Thats looking really good - hope the start up goes well
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Wow, that does look good Johnny, it's a great job you've done there.
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Was going to be semi clever and photo all parts before assembly begins but realised I don’t have seat back from restorers. But picture tells the story so far.
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Oh-err. Do crack on please. :P
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Yes, first thing to do is get that tank off the garage floor before it becomes a victim of my clumsiness! 🤭😂
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Very clean work area, looking forward to this build-up.
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Well done Ken! Yes I’m needing to order a new shell.
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That would be great Ken! Just PM if you come accross anything.
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Excellent Ken, the ones I have already are not perfect so this will match perfectly! Yes just the shell required.
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Hi Johnny,
Great work going on there - that's a very rapid transformation. My latest 400/4 was taken to bits in 1986 by the PO (now deceased), I inherited it in 2001 and it only ran for the first last week!
Anyway, I'm not familiar with 750 parts details but if the indicator bodies and lenses are the same as 400/4, I have a few brand new genuine ones if you are stuck.
See you soon,
Ian
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No point in rushing these things Ian!😂 Thanks guys for your help on the indicator shell front. Ken I will pass on address through PM. Ian thanks for your offer I will probably go for Kens used one as the others are not new. Cheers for that and catch up soon.
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That was so easy! Hope the rest of the build goes as well.
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Yes, that's the way to do it, so easy, I did mine the same way with the help of my gransdson and no scratches either.
Cheers
Dennis
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I was going to enlist the help of her indoors Dennis but decided to have a go myself, worked quite well. Next job get it up on the bike lift.
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I'm reluctant to get help from 'her in doors' - they seem to be wired differently! Wouldn't swap her for one who was wired the same though - might be a fella! We were carrying an 8x4 sheet of ply t'other day and it sometimes gets breezy here in Orkney, so I suggested turning it flat - why do they always twist the opposite way??? Perhaps Julie can explain? :) :)
Ian
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I'm reluctant to get help from 'her in doors' - they seem to be wired differently! Wouldn't swap her for one who was wired the same though - might be a fella! We were carrying an 8x4 sheet of ply t'other day and it sometimes gets breezy here in Orkney, so I suggested turning it flat - why do they always twist the opposite way??? Perhaps Julie can explain? :) :)
Ian
Us women would be turning the sheet of 8x4 the correct way, it's usually the man on the other end that is turning it the wrong way 😂😂😂😂😂
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Because Men are from Mars and Women are from Venus. Which makes sense as Venus is a gas giant and women are full of hot air.
😂😂😂😂😂😂https://media.tenor.com/images/193540b09009c90bb91cf6bc251b1cee/tenor.gif
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Because Men are from Mars and Women are from Venus. Which makes sense as Venus is a gas giant and women are full of hot air.
Crikey Ken, :o ;D ;D ;D
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Don’t really know what to say after previous comments.😂😂😂 I did get a help to lift the bike onto the bike lift and yes Ian she did go the right way!😂
Temporary fit of new tapered bearings yesterday after concern after reading different reports about these taking up a bit more of the steering stem and leaving very little threads for top nut. These were just right leaving as many threads as was in the nut. Must remove again fit new steering lock and grease up. First experience with powder coating too, my that stuff don’t half take a bit of shifting if you get it where you don’t want it.
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Waiting on new rubbers for the headlamp ears before final fit of forks then front wheel. Swingarm, centre stand, oil tank and coils fitted today, in between searching for lost parts, some of which were never there in the first place.
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Great photos - looking good. 8)
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Shiney...................Love it, well done Johnny, keep it up, it's terribly addictive isnt it? ;D 8)
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Indeed it is Roo! This is the fun part when you get by the muck and the skinned knuckle stage.😂
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Isn't it just ;D
I now have a fond affection for wiring after doing the 400 loom........Who knew? ;D ;D ;D ;D
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Managed to squeeze in a bit of time on the 750 this last couple of days. Filled with oil and turned her over for first time today, seems to be oil pressure, activates the oil pressure switch at least. Itching to get her running but will carry out some wiring connections at headlight and fit exhausts before that happens.
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That's the exciting time when you get the first blat of life and she rolls over. It's realy tempting to have a late night and get evetrything hooked up but in my experience it's really counter productive. Super chuffed for you Jonny, keep us posted on bits and bobs, she's a beauty :) ;)
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Major leap forward today, decided to give her some fuel, she fired up first second of pushing button. Delighted! Oil pressure light went out almost straight off, so kept her running for few minutes. No sign of any problems ran good and idled. Roll on spring time so I can get her out for a run. Bit of fettling yet including vacuum sync on carbs, but limiting running time in garage so I can bed it in properly out on some descent hills. Another one saved!
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Must have been a buzz, well done and good luck with the rest of it.
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Splendid news, well done that man. Once you've decided today's the day, I get quite excited and engrossed in all the pre-flight checks......love it. Well done Johnny :) :) :) :)
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Fantastic news John, well done you 👏👏👏👏👏
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Thats a great feeling when that happens. Well done you!
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Great news John roll on the summer :D 8)
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Brilliant news - I guess even experienced rebuilders are relieved when it starts as it should.
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Indeed Ted! It’s certainly not a given that everything is going to be right first time. I’m not a mechanic, just an enthusiast. I was well impressed with the way this bike burst into life compared with the 550 after rebuild. Even now unless you are running every day it needs a bit of coaxing to start and warm up but great on a descent run. Must be down to carbs. I am going to raise the needles one notch in the 550 just for interest before spring time run. But defo looking forward to getting out there on the 750. I wanted one when I was 17, so I’ve waited a while. Just a small note on oil pressure. I tried and better tried to raise oil pressure without starting be blipping the starter button and also kicking over in bursts of 50, also putting bike on side stand and squirting a dose of oil into oil gallery port to rear of cylinders, but to no avail. After reading much on the forum across the pond, I was given the encouragement to try and start the engine and shutting it down if there was still no oil pressure. I also poured 0.5 litre oil into rocker cover. Maybe all my prior purging helped?
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The initial oil feed is affected by air locking in the oil pump head ordinarily with these engine, especially if it's been evacuated from sitting or stripping the engine.
All oil has to pass through the filter housing to get to the galleries, and onward distribution. If the route out from the pump head is effectively sealed from oil used to assemble (or complete drain down from sitting unused for long periods) then the pump is reluctant to fully prime and push the oil against an ongoing fairly well airlocked distribution.
If you remove the oil filter (complete housing) and crank with the spark plugs removed, then you'll see the oil come out of the feed tube into the filter location (no air pressure to work against lets the pump head prime quickly) as soon as you see that, then replace filter housing and then it won't take long for the fully primed pump head to complete the rest.
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"Even now unless you are running every day it needs a bit of coaxing to start and warm up but great on a descent run. Must be down to carbs. I am going to raise the needles one notch in the 550 just for interest before spring time run."
If you want to try an easy bias (without dismantling the carbs) to assess it a small amount richer, then use the idle airscrew and set them all 1/4 further inward (so if 1 1/2 out, go to 1 1/4) which will just bring up the low speed running mixture faster and may give you the effect you need to stop it feeling so "cold blooded" initially.
The idle jets on these bikes generally contribute about 1/3 of total jetting demand, and so influence the overall fuel strategy quite a fair way up in throttle opening.
Using the above adjustment won't alter the overall jetting, but it will bring the mixture up on a steeper response curve (vs vacuum curve) and change the way it runs.
Virtually free time wise to try it too.
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Just a note, if the "airscrews" are on the filter side of carburettor body they work as above description.
If they are on engine side of carburettor body they generally modulate fuel rather than air, and so work the opposite rotation to get the same mixture effect.
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Thanks K2-K6 for the info regarding oil circulation on the 750 and fuel situation with the 550. I have done a fair bit of fettling with the Pd46a carbs on the 550. I have had the carbs off three times, maybe I made a mistake by not replacing the slow jets, but I did give them a good clean. Now I have adjusted the screws both ways in and out but ended back to 1.5 turns which is the base mark for these carbs on this bike having not made any improvement on the starting. Also to take the bike above 60mph and 4000rpm works better opening the choke with throttle opened, hence my theory for needing more fuel. Maybe I should replace slow jets yet? I know these carbs are tricky but a bit of a challenge too as far as I’m concerned. Not going to do anything with the 550 for a couple of months until 750 is finished and road ready.
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This is the state of play now. Just ordered Dot5 silicone based brake fluid (won’t strip paint), fork oil to put in also and still deliberating over number plate design. (Pressed aluminium black and silver probably)
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This is the state of play now. Just ordered Dot5 silicone based brake fluid (won’t strip paint), fork oil to put in also and still deliberating over number plate design. (Pressed aluminium black and silver probably)
It looks fantastic Johnny.
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Looking good John - I'm sure you are very proud of that build
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It’s a beauty. Like the colour.
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Thats a stunner Johnny, well done mate.
You've got to be 'beaming from ear to ear' with that? Huge pat on the back from me. 8) ;)
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i'm not happy with this post at all. it's progressing way to fast for my liking and showing me up! i think i've had my projects since 2016 and i still have loads to do :( nice work though :D
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Very cool looking bike, well done👍
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Turned out nice that Johnny, wonder why Honda didn’t put the calliper bleed nipple right at the top like the 500, can’t make it easy to bleed and may explain why so many complain of spongey brakes. GL1000 suffered with the same design fault iirc.
What colour is that, doesn’t look like the gold.
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Thanks guys for kind words, to be fair I didn’t expect it to be done so quick either. It’s flake sunrise orange Ken fluorescent light is making it look a lot lighter.
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Help! Guys I was very concerned about this. Ran bike up yesterday to run through the gears and could only select first gear with difficulty getting Bach in neutral. Couldn’t get any other gears. Took gear selector cover off this afternoon and all gears no problem. Downgraded from major incident to major irritation. Here’s photos see if anybody can see anything wrong before I put cover back on.
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having looked through my pics, the only thing that looks different to mine is the spring that sits on the lever that rolls on the selector drum. your spring doesnt look like its sitting on the notch on the top surface. dont know if that makes sense
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Johnny, I'd check the order of the parts on the shaft of the arm that rolls on the drum using the parts book schematics - I seem to remember having similar problems on one of the 750's I have built
https://images.cmsnl.com/img/partslists/honda-cb750k2-four-england-gear-shift-drum-stopper_bigma000039e13_f4f1.gif
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Thanks guys! I see what you mean spring could be wrong way round? Yes I will check order of selector parts.
Annoyed now with myself for not paying more attention when I put it back together.
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Had a go at the gears this morning and sorted the spring that appeared to be wrong way round but didn’t make any difference. It appears that the neutral rotating wheel is fouling on the inside of casing??? That’s easy sorted but it goes against the grain to get into it with the dremel. These are all original parts that were on the bike before. If you zoom in about photo centre you will see small nick.
Ahh different crankcases though!! (Should be the same)
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Don't hack anything yet Johnny, I think I can see what the problem is by your photo, I'm just trying to find something to show you how it should be assembled.
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The 1st mistake is that you have assembled the gearbox and put the neutral switch in last. The way you assemble the 750/4 gearbox is put the drum selector in first, then fit the neutral switch then the rest of the gearbox. The way you have it set up at the moment, the selector drum is being pulled out by the little jockey wheel thingy. I will post a couple of pics in a minute.
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You have the little wheel sitting BEHIND the selector drum like so, which is incorrect, this pulls the drum forward and OUT causing impingement on case. In effect, you are pulling the selector drum out too far.
[attachimg=1]
The little wheel needs to be sitting ON the selector drum, so as not put any pressure on the selector drum so it sits in the correct place.
[attachimg=2]
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Additional to Julie's information, does the outer disc of the drum have distortion at about 1:30 on a clock face ?
I know a photo can give distortion but that's usually at the extreme edge of image, this looks as if the disc face is bowing outward at that point relative to the remaining part of that disc.
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Thanks very much guys. Julie I have checked this and here is my pic taken just now.
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Seems to be a flat spot on the disc. I have checked other pics and they seem to be same.
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Thanks very much guys. Julie I have checked this and here is my pic taken just now.
Something is bent there John. I'm not saying it was but it could have happened by trying to force the gears. Best thing is to take all that lot apart and see if you can select gears manually by turning the selector drum by hand and rotating the back wheel. If you can select gears that way, it's a selector mechanism issue, if you can't select gears, it's an internal gearbox issue.
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Thanks Julie, the gears all select smoothly with mechanism and no cover on. But I will take mech apart and re check, the thing is the selector drum and the neutral lever position cannot vary. The other things is I don’t like the way the alternator casing and the gear mech casing are absolutely jamming against each other.
Sent from my iPhone using Tapatalk
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It’s sorted! Working great through all gears. This definitely helped.
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And a small hand file where it was jamming. Not much clearance going into second gear!
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Great, at least niggles like this can be dealt with before the bike goes on the road. I'm sure there is nothing worse than taking a bike out on her maiden voyage and everything jamming up 😭😭😭😭
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Indeed Julie, thanks for you support and input. I had to take very little off the inside of cover for it to clear. Roll on spring time!!😀😀
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I'm very surprised at that outcome. If your having to remove metal from the casing something in the mechanism cant be quite right. This is a 47 year old bike that hasn't had that problem before?
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It would suggest to me either a mishmash of parts or a very slightly bent pivot for the roller arm
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Just for your info Johnny, here are a couple of photos from 2 of Grahams engine rebuilds. It will give you an idea of the clearance from the case there should be when everything is straight and true and assembled correctly.
[attachimg=1]
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Thanks Julie for posting pics! It is still a bit of a mystery to me, the only thing I can come up with is that the stopper plate is not the correct one for the bike. The main thing is she moves nicely through the gears.
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One or two more teething issues! Horn stopped working so stripped horn and got it “honking” again. Went to start bike then and it ran like shit. Not firing at all on 2 and 3 must have disturbed coil connections when I pulled horn wires apart. So removed tank, renewed connection on yellow coil wire and hey she’s running good but not starting on the start button. Starter is whirring but not engaging with engine. Removed alternator cover and rotor and starter wheel spinning on shaft, bolt on the crankshaft end completely loose. Thing is they were never removed from crankshaft when the engine was stripped, nevertheless should have taken the torque wrench to it and checked it was tight. All torqued up now and ready for another spin round the block on a dry day. This is exactly why I am keen to get going to iron out all gremlins before that sunny spring day. “Happy Days” 😃😃
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Thanks Julie for posting pics! It is still a bit of a mystery to me, the only thing I can come up with is that the stopper plate is not the correct one for the bike. The main thing is she moves nicely through the gears.
As long as she is a good mover in the gearbox dept. that's all that matters. Just read your other post on the teething issues, this is the benefit of finishing a build in the winter. All the issues will be sorted ready for the good weather.