Join Date: Mar 2013
Location: Melbourne, Australia
Motorcycle: 1998 750 SRAD
97 750 - losing cylinders between 50 and 80 Celsius
I've been away a while - too much work and not enough motorbike!
anyway, I've come across an 'interesting' problem recently.
The problem is that between about 50C and 80C (temperature) the bike runs on only 2 or 3 cylinders. A spray of WD40 on the headers shows either #3 or #4 will cut out at this time. After 80C the cylinders come back on and she runs normally. And yes, when started from cold (no temp reading on guage), she starts super easy and even without choke.
I have tested her out 3 times and the same behaviour each time. If she's hot, she will start and run fine. If she is cool, then she starts but loses cylinders between 50 and 80C before firing on all 4 cylinders when warmed up.
I recently replaced stator and upgraded reg/rec. Was running well, and meanwhile I have been fine tuning the carbs (Factory Pro kit) over the past weeks.
Does anyone have any ideas about what this problem is caused by..? have you heard of this before..? It is baffling: the cylinders only cut out in this temperature range...which confuses me no end...do I chase carb set up or electrical (perhaps coils)?
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