1961 CB72 Project

G-Man · Post by **G-Man** » Wed Apr 08, 2015 3:41 pm

I had a brief ½ hour tonight to look for a replacement for that last pitted gear. The one from my box of 'nasty gears' really was a bit too nasty with corrosion damage but I avoided stripping the '63 motor when I found another 'orphan' gearset I had salted away. I cleaned both, 'just in case' but the one on the right really didn't make the grade.

I stripped the countershaft and threaded on the replacement but the rest of the assembly and testing will have to wait until later in the week.

G

Seadog · Post by **Seadog** » Wed Apr 08, 2015 3:46 pm

G-Man wrote:Seadog

Here you go. The damage is on the surface of the gear teeth. This is not the worst gear but the pitting here could eventually turn into cracks from which the gear tooth would break up.

Thank you. I had seen that, but didn't think anything of it. Now I know better.

G-Man · Post by **G-Man** » Wed Apr 08, 2015 3:53 pm

Seadog

That gear might be OK but gearboxes are not things to take chances with in my opinion. I had a Moto Guzzi gearbox seize on me once and it wasn't a pleasant experience.....

G

Seadog wrote:
G-Man wrote:Seadog

Here you go. The damage is on the surface of the gear teeth. This is not the worst gear but the pitting here could eventually turn into cracks from which the gear tooth would break up.
Thank you. I had seen that, but didn't think anything of it. Now I know better.

G-Man · Post by **G-Man** » Thu Apr 09, 2015 2:41 pm

I realised as I was assembling the shift drum and forks that I needed to put the breather two baffle in place. This is only used on the '61 "breather tower" engines and is held in by a spring contained in the lower case.

The tab washers for the selector fork bolts needed annealing before they could be re-used.

Selector forks, drum and gear shafts could then go back in place.

With all the parts in place I was able to check gear operation and whether or not I needed to use offset cotters.

It all looked pretty good without any adjustments so I am happy.

Next job was to fin the crankshaft bearing looting dowels, remembering to put the hollow ones in place for the centre bearings where they form part of the lubrication system.

And then the crank could go back in place.

I had one last check around for burrs on the joint faces but everything felt good. Next job - put some jointing compound on the faces and button things up.

G

Seadog · Post by **Seadog** » Thu Apr 09, 2015 7:45 pm

You've come a long way. Well done. When you apply the joining compound to the case, I'd like to see how it's done properly.

jerry · Post by **jerry** » Thu Apr 09, 2015 9:37 pm

Me too. :-). Have done it maybe 200+ times over the years. All the best Jerry

G-Man · Post by **G-Man** » Fri Apr 10, 2015 12:21 am

Over to you, Jerry!

G

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1961 CB72 Project