HOME and how to join Forum Open Area General Scott topics Starting when hot. Re: Hi John

#5850
Roger Moss
Participant

Hi John. So nice to have your input. For newcomers to Scotts,– John is well worth listening to!
All interesting points, but so often you can have an unappreciated build up of wear that can cause such problems. Generally if you do the same thing, then a mechanical system in the same state will give the same result. The question I would ask, is, was it always like this, or is this a problem that has developed? If it has developed, then how quickly has it done so. Problems due to wear develop slowly, so if the decline was fairly sudden, then it isn’t that. You must think carefully if you have changed anything that could co incide with the onset of your problems.
If the carburation was ok and you have changed nothing, then I suggest it might not be the problem. In the general cause of elimination, however, by all means dismantle it and clean it out and do not forget the float chamber. When you finally get it to fire, after it has beenn reluctant when hot, does it blow lots of smoke from the exhaust? You do not, by any chance, have a cylinder wall oiling system in working condition I hope. The valve system under the tank is prone to seep oil so that when you stop, if you have left the oil on, it gets choked with oil. I remember getting the “red staggers” pushing a bike in this condition!
If you come home and the bike is hot, try draining the wells and see how much is in there. Put the doors back and try starting it with empty wells and see if it improves it. The most likely culprit is the mag losing voltage when it gets hot. As the voltage required to fire is relative to the plug gap, reduce the plug gap to about ten thou and try again. Does it make any difference? The bit about the oil, was valid for wear related problems, and incidentally, Castor R40 is the most excellent gear box oil you can use, but do not use it as a substitute for ensuring the outrigger can not move under low gear acceleration. Correctly done, the high gear bush should last for decades, but strip a few boxes and look at the wear, and consider how much power has been dissipated in this unwelcome friction. Such a simple looking engine. how deceptive!