Hi all, having a problem with the dommie (500 twin) when heading up long hills, don't particularly have to be steep but usually long, the old girl drops a plug and cylinder, typically the left side, and coughs and splutters accordingly....Any suggestions as to why this is happenning...she runs fine on all other inclines and surfaces...thinking maybe a timing issue ? ? ? Any advice greatly received
#1. "RE: Dropping a cylinder" In response to Reply # 0
Sam, since you only have one carb its not likely a carb issue - or both cylinders would have this problem ? How can you pick which side its on - this can be quite difficult/deceptive while on the move ?
So the candidates are 1- plug fouling or breakdown due to oil burning or air leaks. 2- breakdown of the ignition on one side. Could be plug cap, plug lead, maggie pickup (carbon brush) or carboning or problems with the slip ring in a certain position.
Anyone ridden behind you to see if it puffs oil smoke anywhere - particularly on acceleration (rings) or on the overrun (valve guides).
If the timing is out it could accentuate the above problems - you verified it is correctly timed - on each cylinder ?
#2. "RE: Dropping a cylinder" In response to Reply # 1
Just a further thought on this. How new are your valves/guides, and what is your valve clearance like ? Its not impossible for a sticky valve to do this. If they or the guides are new then maybe one is too tight, either in the guide or with tappet clearances ? Or if the motor is well carboned up then maybe the same, although this is bit rarer these days, with modern oils, than it used to be...