KR-1S.co.uk Forum

As the title says,i tried starting my bike this week and the revs went through the roof!i hit the kill switch before any damage was done.This is what i have done to try and remedy the problem:checked fuel tap-it's not leaking,stripped carbs,checked float heights,tried several spark plugs,checked float valves weren't sticking,checked slides move freely and tick over screws set to minimium,throttle cable has plenty of slack.I tried a spare set of carbs and still had same problem,bike just revs like hell without touching the throttle.I thought it might be the choke,but again the cable has the correct amount of free play.Has anyone had this problem before?What should i check/try.Any thoughts/recommendations much appreciated.

Rich

Air leak
Flywheel side crank seal shagged

Thanks,you could be right as the engine is second hand.I thought i would try it out to see if any good,looks/sounds like i bought a dud.

Check the carb manifold rubbers and reed block housing gaskets for leaks first.

Thanks,I will take them off and inspect for cracks.

You could also try spraying some fairy liquid/water mix around the intake rubbers/area,will bubble up when running if there's an air leak in that area.

I can't believe an intake-airleak could cause the engine to "rev' through the roof" (allthough I might be mistaken). it only draws extra air into the engine, where should the fuel come from to rev that high ?

If you have an electric drill that has enough power, I would drain the carbs, let the engine run on the electric drill and than spray brake cleaner on the intake rubbers : if any firing occurs, you have a leak

I think i may have found the problem,i've tried another set of intake rubbers,but problem still persisted.Had a good look at the carbs and noticed the slides were not fully closed even with loads of slack on the throttle cable.Tried a different cable,now slides are at the very bottom!Trouble is now i have fiddled with the idle adjuster screws i am unsure how to set them roughly before starting engine.I think i have read you can stick a drill bit(5mm)to set them?I did try starting the engine today,it fired up briefly and didn't rev like hell,ran out of time will try again tomorrow.Fingers crossed!