Starter gear cover bolt length

[3potjohn]

After a valiant attempt at emptying the “holiday fridge” here in Malaga prior to returning to the sweltering heat of Exeter, I find that I am imbued with enhanced cerebral activity.
( ref https://m.youtube.com/watch?v=0tHlefllnYA )

One question: what are the correct lengths of the three long bolts in the starter gear cover? My Kokusan ign bike has three of different lengths and I think one is incorrect.

[morini_tom]

There are I think two different lengths.

When I can get to a disassembled case I’ll measure up for you,

[3potjohn]

Thanks Tom.

[morini_tom]

Yes can confirm 2 different lengths for the long bolts.


The one which goes through the centre of one of the gear clusters is 90mm and the two which go towards the front of the cover are 100mm.

If you look on the inside of the primary drive case you’ll see that the 90mm bolt is threaded into the clutch/starter cover whereas the 100mm bolts go all the way through into the left crankcase half.

You could fit these bolts in the wrong place but you’d get poor engagement in the crankcase with the short bolt at the front, and I suspect the long bolt in place of a short might touch the inner wall of the crankcase half before bottoming out. I’ve seen a few stripped threads in these locations and suspect muddling the bolts might be part of the problem.

[3potjohn]

That was very useful, The top bolt was 100mm, bottom 105mm and central bolt 95mm.
Suitably filed and ends refinished.
Many thanks
John