Misfire?
 

I rode my bike this morning - warmed it up fully and off i went as usual.

Going through country side around 40mph, my engine had a flatspot mid revs and low revs when changed up a gear, when i pulled on the throttle, it felt as if it was running out of petrol (and theres loads in there as i filled up) and just bogging down.

Coming to the next village, i slowed down and dropped a cog, let the clutch out and there was backfiring!

My thoughts on this?

Misfire perhaps?

Now my bike has been serviced a month ago by JHS racing who are apparently Sv650 specialists. Fine and dandy.

But what i want to know is, what are the possible causes? And are JHS liable to repair them? If its misfire due to a faulty HT lead or spark plug, surely JHS should have spotted this?

Im absolutely enraged, as i paid £600 for a major 15k service, and a MONTH later... THIS SHOULD NOT BE HAPPENING!

Any help and advice appreciated.

Re: Misfire?
 

Was it raining, or the roads wet?

Re: Misfire?
 

Roads dry this morning dave - i know of the spark plug issue getting soaked.

I ride a 1999 SV650SX, and the only thing ive done recently is taken the battery out to charge it. It could be terminals methinks?

I read another posting on here - but my tacho doesnt appear to be doing anything wierd, or i dont think it has. Ill check when i next ride tomorrow morning. My terminals are securely screwed on, and the cap put on the positive.

Other than that i dont know what it could be??

Spark plugs and fuel air mix is what i was going along the lines of - but dont know.

Re: Misfire?
 

My 99ey has been doing kinda the same thing for a while now.
Especially the "drowning" thing when adding throttle after driving in low or med rev for a little while.
My idea is that the carbs are unsynchronized, or the needles (Dyno Jet kit) need replacement. I don't hope it's the latter. I plan to work out the problem before spring time.

Re: Misfire?
 

Carb icing?
Damp cold weather at the moment so if it cures itself as soon as you stop and let some warmth around the carbs that could be it.

Re: Misfire?
 

I made sure it wasnt the carbs icing - i took my bike out for a good 30min ride this morning in freezing cold weather...

No hiccups from the engine at all. I wonder what it could have been?

I hope james over at JHS manages to find something as im going to london tonight!

Re: Misfire?
 

As you said higher up you have checked the plugs but that's the only thing I could guide you towards.