running fast then slow irregular revs smoking a bit spark plug sooty any ideas. there is no choke or throttle on this model just bought like this s/h

ian bullingham, June 2008

I had the same problem. Machine two years old and was running very poorly. Solved it simply by stripping down and giving it a good clean. ie cleaned out air filter, new spark plug, took off cylinder head and cleaned off sooty deposits, cleaned out fuel intake. Running as good as new now.

David., July 2008

overrich fuel air mixture causes:dirty or clogged air filter,incorrect fuel float height.faulty float/valve/needle.renew filter.strip and clean carb.reset/check float function/height.check diaphrams if fitted.

caine, June 2008