UK CB77 restoration, here we go...

adeskey · Post by **adeskey** » Thu Dec 15, 2016 4:27 am

Thanks, I cut a couple of lengths of 2 inch angle, marked out with the profile copied from the frame, and cut/chain drilled the shape. Blended the corners, removing all burrs and drilling to suit the bolts.

Some fettling to get the correct fit. All in all the sort of thing to get this project off to a good start.

adeskey · Post by **adeskey** » Tue Dec 20, 2016 11:20 am

A couple of days ago I decided to dismantle the engine. It mostly came apart straightforwardly as it transpired that it had been apart before...not sure why yet, that might become apparent later.

Having made an alternator rotor puller from an old fuel injector, (correct thread - M16x1.5) which worked a treat, and overcame the stubborn barrels that liked being attached to the crankcases, I was able to expose the innards which are shown below.

It mostly looked OK, despite having been rebuilt with Red Hermatite or similar. But I am concerned that the gear engagement is not as it should be. Second in particular is marginal on engagement so I will now trawl through this site to understand about offset pins.

Another point of note is the pistons which are 0.05 oversize, and evidence of water being sat in the bores for some time, and seized piston rings means that I am now on the lookout for either 0.75 oversize pistons or a replacement barrel/cylinders.

It looks like I have resized this picture too much...oops. Must try harder.

adeskey · Post by **adeskey** » Wed Dec 21, 2016 12:40 pm

Here is a better, but not focused, picture of second gear in maximum engagement. Not a lot compared to 1st and 4th which have full engagement.

Am I correct in assuming that by fitting the appropriate offset cotter (I haven't seen one yet) that the engagement on the gears for each pair would just be 'evened up', as the shaft gives a fixed movement due to the grooves? So 4th would lose and 2nd would gain.

Also I measured the endfloat on the selector shaft and selector forks and got around 1.25mm, most of which is play between the selector pin and the shaft groove. The shaft I can shim out, but the rest?

G-Man · Post by **G-Man** » Wed Dec 21, 2016 2:43 pm

Adesky

If you look to the right of your red highlight, on the other side of the gear is a wire circlip. This locates the two cotters, which are either flat, or staggered (offset). They locate in a groove on the shaft and locate the gear. Not sure that you will get a massive amount of extra engagement but the taper on the dogs will pull the gears together when you put torque on.

Part #14 is the cotters.....

http://www.cmsnl.com/honda-cb77-general ... ml#results

As for endfloat on the shafts, you should be able to shim them but the clearance may be due to worn bushes.

G

adeskey wrote:Here is a better, but not focused, picture of second gear in maximum engagement. Not a lot compared to 1st and 4th which have full engagement.

Am I correct in assuming that by fitting the appropriate offset cotter (I haven't seen one yet) that the engagement on the gears for each pair would just be 'evened up', as the shaft gives a fixed movement due to the grooves? So 4th would lose and 2nd would gain.

Also I measured the endfloat on the selector shaft and selector forks and got around 1.25mm, most of which is play between the selector pin and the shaft groove. The shaft I can shim out, but the rest?

cknight · Post by **cknight** » Wed Dec 21, 2016 3:39 pm

When checking end float on the main shaft, be sure to have the clutch basket and it's circlip mounted. Regards, Chase (Post #305! Guess I'll retire now.)

adeskey · Post by **adeskey** » Wed Dec 21, 2016 5:22 pm

Thanks G and Chase, I have now seen the light....

I noticed that the engagement problem also afflicted 3rd, but not as much. I will investigate further.

I am a font of knowledge when it comes to Citroen DS cars, so it is an interesting experience to have the boot on the other foot, so to speak.

I appreciate you help gentlemen.

LOUD MOUSE · Post by **LOUD MOUSE** » Wed Dec 21, 2016 6:34 pm

Now would be a good time to cross 2nd and 3rd gears. ....lm

adeskey wrote:Thanks G and Chase, I have now seen the light....

I noticed that the engagement problem also afflicted 3rd, but not as much. I will investigate further.

I am a font of knowledge when it comes to Citroen DS cars, so it is an interesting experience to have the boot on the other foot, so to speak.

I appreciate you help gentlemen.

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UK CB77 restoration, here we go...