LCGB Forums

I have taken apart and rebuilt a few engines all with no massive issues. This one however has me perplexed. Fitted a new RB250 barrel and piston to the new GT case, GT crank, Sil endplate and iwis chain. Using kit from my old RB such as the same 5 speed cyclone box, and AF 6 road clutch.
As soon as I put the chain on and attach the side case the kickstart just locks. You can virtually stand on it. I'v took it apart and re-shimmed it re lubed it...turns great with no chain. Can turn it from the flywheel using a holder but fastenthe chain and stop.
The front sprocket is not touching the case. The kichstart is not touching first gear.
Is it the cumalative effect of all the new crank, seals and barrel and piston or am I missing something?

Can you turn the motor over with the chain on but no side case? If not, check the chain pins are not fouling on the endplate bush, if ok I'd suspect the kickstart shaft is too tight against 1st gear, jamming it when the casing is fitted. I had this problem with the last cyclone I fitted.

with no side case I can rotate the chain via the flywheel with chain fitted. I originally sank the end-plate studs thinking it was the guilty party.....I ground down the end of the kickstart housing in case it was catching..it travels the initial part of the ramp then ....STOPS...how did you sort yours?

I cut the ramp off then converted to the casing stop plate and cured it.

I did the same with the ramp removal (a la AF)...what do you mean by casing stop plate?

Sorry I meant the LI bolt on ramp plate. I've seen the pins on the kickstart piston also catch the engine casing so worth checking that.

The clutch ears can sometimes catch. This usually causes clutch slip, but I suppose if they are really tight this would jam the clutch......just a thought.

Going to spend a few more fffreezin hours in the workshop trying to sort this...i'll keep you informed as to the outcome...hopefully

can you push start it?

Wack you are a genius...kickstart pin catching the extra metal strengthening of the new GT case. Not by a little nor a lot but probably 4mm depth 8mm along. Also found with the new GT case that they do not marry up with some original Li endplates (not deep enough) in that 5 speed and 4 speed(SX) 1st gear catches the underside of the plate (using a RIV hub bearing). Should have used my Lidl endoscope I bought for these kind of jobs. Lets see what can frustrate next..

Pleased you got it sorted. I had one cyclone where I had to shim the layshaft before fitting into the hub bearing so that the gears and cluster lined up but then the first gear kickstart teeth rubbed on the endplate. Only cure was a rebate on the underside of the endplate.

on the road..switched the 5 speed for an SX200 box I had so it can go in another engine build. Running well. Annoying compromise though is the raised 'GT' plate on the case..blocks the gear swivel. So rather than grind some away (really tempted) was to raise the gear swivel to clear it...which then catches the gear arm on the clutch arm...put on the skinniest gear arm with a ground down trunion...and clears with a couple of mm to spare...oh and had to put a stud instead of the spigot on the gear shaft arm........ain't no plug and play....