Stripped a 198b engine tonight and like a clumsy pratt, caught my foot and let the gearbox that I'd removed complete, roll out of my hand onto the bench. Managed to keep it together, mostly, but the 4th gear, the last small cog on the clutch side of the layshaft, rolled off and onto the floor.

So, refititng it presents the problem of which way around, as my useless memory can't remember from previous engine strips. It has a flat face on one side and a small boss on the other. Checked the Bultaco manual, Haynes and Clymer and typically, pictures of the cog show it fitted either way around, depending on which book you look at.

Anyone know for sure which way around this cog goes - boss facing outwards towards clutch or inwards to the next gear? I think outwards from what I can remember of other 5-speed rebuilds I've done.

Hi Woody

According to my M129 5 speed Kart engine stripped out on the bench it is raised boss facing outwards towards the clutch. Engine & gearbox is the same as all the other Bultaco engines I have worked on. Cog wear marks in my box of bits also indicate boss facing outwards.

Tim

Thanks Tim, that's the way I was summising. I'd had the magnifying glass on it and tried to suss it from the wear marks but that is a bit outside my technical savvy