Bad stuttering advice

[Rockoz]

H-h-h-h-hiya

Got some symptoms and need some diagnostic advice before deciding what to do.

My 1150gsa in the rain has decided to run rough and surge up and down 5mph intermittently. Once the rain stops it's fine again. Never done it before.

Any ideas?

I also know it must have a tank breather issue as the filler cap gets sucked shut under vacuum again intermittently.

 

[Bubb]

tank breather blocked......

or ignition leads breaking down...


maybe...

 

[beakster]

I've just cured a similar problem on mine, a 2002 single spark, I'd suffered with it for 2 years on and off and tried everything that I could replace. It turned out to be a shorted wire in the loom. Does the oil temp gauge on the Rid fluctuate at the same time? I can post pics if req.