Steve mentioned when I bought the bike that he thought there might be a problem with 2nd gear and he was getting some shuddering in 2nd. As I stripped the bike down before really riding it, I figured I had better investigate this and as you need to split the crankcases to get at the gears, I might as well give the engine a thorough check over and investigation while I was at it.
In no time at all I was down to this
Impressively there was very little sign of wear in most of the engine with the bores, rings and bearing shells all showing very little wear. The clutch basket and centre were heavily notched as you would expect from a race bike and the middle gear selector fork had bent and was heavily worn (forgot to get a photo of this) which I'm hoping was the cause of the 2nd gear problem. Surprisingly there was very little wear on the gears and dogs so hopefully this was the cause of the problem.
With the initial inspection out of the way it was now time to invest in some new gaskets & seals and start the long and tedious task on degreasing, cleaning and measuring everything (This probably contributed to the current lack of enthusiasm....)
I found a good used selector fork from a CB-1 in the spares stash and set about reassembling the bottom end. Something else that was also apparent is that the sprung tabs in the selector drum where in back to front so these were swapped round and eventually I had the bottom end back together. Everything was spinning freely and all the gears were selecting smoothly but until I ride the bike and the gearbox is put under load, I won't know if the issue has been fully resolved.
Here is where I'm up to so far:
The valves have all been popped out of the head and given a light lapping in with new (Chinese) stem seals and so tonight's task is fitting the head and setting the valve clearances. Hopefully I have the correct shims to hand.
After all this, I know understand why engine builders charge what they do, I've lost count of how many hours have gone into the engine so far and did I mention how tedious the cleaning was
Didn't find anything obviously wrong with 5th so fingers crossed all will be ok.....
