Im new to the forum, so if there is a similar thread running, my apologies for kicking things off again.
My son has a 94 RM125. The bike has to be kicked over numerous times to make it start. When it does start it will not tick over and after the engine stops it is still very difficult to start again. I have checked the plug and it shows that the bike is running slightly rich ie. it is grey/black. There appears to be a strong spark (Ive checked this by kicking the bike over with the plug out and held against the engine). I have checked the air filter which is pretty clean and he is running a 35:1 fuel oil ratio (approx).
He has told me that it runs well when he is riding it but even when hot there is still a problem starting it when it stalls etc. He said that when riding it today he felt the revs dropping off before it cut out and it is proving very hard if not impossible to start again. There does seem to be good compression and the spark plug is slightly wet after numerous attempts to kick it over.
I know this all pretty vague but any help will be appreciated.