1976 CB550F1 (what have I let myself in for) Project

[eight0]

The bike is finally starting to look like a bike again.

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I've painted the engine cases using Simoniz engine enamel and baked them in the oven at 220 for an hour and a half.

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I have torqued the case halfs down with the 8mm bolts to 17 ft-lbs checked the crank bearings with plastigauge and as far as I can tell using the gauge on the packet the numbers come out as follows:

1: .038
2: .038
3: .051
4: .051
5: .051

As the clearance tolerance  is 0.08 I think I'm good?

There feels like very little play on the rods too (none vertically), is it worth checking them? I've read that I'd need to order new bolts if I do as they stretch when torqued.

I've had to order a new 16005 bearing as the one in the engine was notchy and looks a little rusty inside. The rest all seem fine.

What else should I be checking before attempting re-assembly?

Thanks in advance!

[Nurse Julie]

You don't need to fit new bolts, it would be a very expensive process if you bought new ones each time you torqued for measuring. The bike is looking good.

[eight0]

Yes I have new primary chain and cam chain and also new dampers to install.

It does make sense to change the bearings as I'm In there, I've gone this far! I know the marks on the crank is supposed to be difficult to see but I can't see anything!

Good news on the Rod bolts, I'll do that. What is the clearance for plasitgauge?

[eight0]

Thanks oddjob, I'll give it a go. Where are the markings usually? Are they separate on each counterweight or all together?

[eight0]

Thanks Oddjob. I still can't see them.

Heres some pictures, hopefully you can see something I cant!

High res: https://photos.app.goo.gl/xcCaiNHT7C3XhXyh8

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[eight0]

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[MrDavo]

I had to find a set of these markings on a CB750 crank that I got from Ashimoto, the only way I could see them was when I took the crank outside into direct sunlight. Suddenly, there they were!

You are looking for grafitti like scrawly scratches, rather than neat stampings, its only a surface scratch, they aren't very deep. It wasn't something I could have taken a picture of anyway, but I have a sneaky feeling that the marks on my crank were on one of the inner cheeks, so its not a given that they are on the outside. maybe it depends who did them, and how bored they were at the time.

[eight0]

Thanks Davo, Yeah I saw Hakaweek's videos and his 750 marks were on the inside web. Mine looks like it got hot at some point so if it was there, you cant see it anymore.

Apologies for all the photos!

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Cant see anything on the others either.

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[eight0]

Also, Here's the Rod bearings.

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[eight0]

God it's like those magic eye pictures you used to get in the paper, I could never see them either.

[Bryanj]

Other answer is to find somebody really good with a micrometer as you need accurate measurements to 1000th of a mm which is not easy, the factory used air gauges where you have a tightish fitting clamp over the pin and put a know air pressure through jets on the arms, more clearance = bigger gap and air gauge cal be callibrated in sizes.
I have in the past fitted all blacks and run the engine in for 500 miles, it does work---racers used to fit all greens i think for more clearance.
Remember Honda used to build these with clearances as if it had already been run in and the surfaces just needed final bedding in

[Nurse Julie]

God it's like those magic eye pictures you used to get in the paper, I could never see them either.

Taking a photo with a flash also helps find them after wiping the area with petrol.

[K2-K6]

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For a little training

  a shark going from right to left,  in smarties.

[eight0]

Haha what shark!!!

Nope I can't see anything. And now I'm high on petrol fumes.

Last load of pictures promise. If you can't see anything either am I better using the original or going all green with graphogen?

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[eight0]

Hmm interesting. So you can see some colour on No 3,4 and 5 bottom bearings. In real life they look more brown than this, but it could be black thats lost some pigment. They all look the same colour but No 5 is most visible.
There is no colour visible on 1 and 2 bearings.

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The markings on the case are BBAAA, I know without the numbers that doesn't mean anything though.