4 replies to this topic

[ianzz]

REV3 250 2001, hot misfire, stator rewound, triggers replaced i think, o.k. for a month, misfire back, cdi replaced, plug, kill swith replaced, coil and plug cap from another bike tried, still misfire, next expenditure will be a gallon of petrol to torch the fuker, any suggestions or help appreciated!

[0007]

First step is always to eliminate things
Find a "Spark gap tester", bottom line with this thing is it will tell you if you have a weak spark, you increase the gap til you misfire, it should jump 10 mm
If it does, you do not have a spark issue, you can ride the bike with the gap tester installed, when you duplicate the problem, look at the gap tester

If it does not:
Do you know anyone else with the same bike?
If so I would use "Peak Voltage" test on the pick up and power source coils, generally you need a peak volt adapter, any bike shop should have one
No idea what voltage you should be looking for but that's why you need another bike, test the good one and compare to the bad one

[spawtydawg]

It may well be the stator, I had mine rewound on my 2001 model and when I put it back on it was still
misfiring. After a lot of head scratching it was sent back and found to be faulty, they exchanged it
and now its fine. Or as 0007 says find one that is running ok and swap parts over, it can be difficult
I know. Best of luck.

[Dadof2]

See if you can find someone with a PICOscope who knows a bit about / has an interest in motorcycles. If someone has a PICOscope chances are they will be able to apply car component testing practice to your ignition system quite easily. PICOscopes are common in car engine management diagnostics and they are very useful for detecting faults causing intermittent symptoms. If you contact http://www.picotech.com/ they should be able to tell you of someone in your area.
If you only have a multimeter check the coil (all coils) resistances and compae them with known good ones.
Cheers

[Steve_E]

Hi, Start With The Basics, Might be worth checking all the connections at the multiplugs. The spade connector that goes to the coil can be troublesome replace it with a new crimp as it usualy corrodes where the wire goes into the terminal. And finally check the spark plug cap has a good connection with the coil ht lead.
Check the body of the coil has a good earth where it bolts to the frame.

Have had the same problem and turned out to be the low tension wire on the coil. Lucky i noticed it at the last min as i was blaming the stator at first and nearly sent it off for a rewind.