Hello everyone!

so another newbie and not surprisingly I need advice. My 09 xt660r is suffering from surging. It hasn't always been like this and has only suffered since I had the coil replaced at around 1500 miles. I've tried increasing the co as instructed somewhere on this site which hasn't worked. Ive looked at the idle speed but it doesn't sit at one figure in fact its up and down like a yo yo. Is this normal? Should the idle speed sit at a constant figure? Any suggestions will be welcomed. This is my 2nd xt and I don't understand why when I bought it it was fine and now it surges more than my old 05 model.

Dave B

idle should very much be constant.

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Hi

hmmm as I thought. Any suggestions as to what could be causing this? I guess this could be the cause of the surging if the revs are up and down?! could it be the replacement coil that yamaha fitted?

If that is all that has changed since the surging started then I think you have answered your own question. Unless you were a fly on the wall when the replacement was fitted, you have no way of knowing what was actually done.

I guess I know that but I was hoping it would be something I could sort without having to go to the dealer. They're so full of it and I don't believe they know what they're talking about especially when I asked them about this problem and their answer was "it might just be how it is" I've learnt more today from this foum and trust it far more than any dealer.

Thanks everyone!

OK, questions,

Why was coil replaced ? Was it replaced for new ? Did the issues start right after ? Are they consistent or intermittent ? Cold or hot issues ?

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Ok this sounds very much like a TPS (Throttle Position Sensor) issue, short of asking you to join the XT Supporter in order to enable you to have the one to one assistance from our mechanical expert Kev, I can only suggest that you ask your dealer to remove, clean and regrease the TPS then fit it back at the correct angle, thus leaving a small open gap for the idle speed to occurr, if there isn't a sufficient gap on closed throttle you can't adjust the idle speed by the throttle body alone, correctly. So try your dealer first and if they are total morons, as most of them are, then come back, join the XT Supporters and Kev will help you to sort it out - guaranteed!

Good luck

coil was replaced as dealer said that was the cause of the bike cutting out. As far as I know it's a new one and yes problems have occured ever since.

Bike cut out as I came to a halt which I know has been a problem for some xt's but then it also cut out at around 60mph which is why it ended up at the dealer. They said the coil was arcing out?

if it is TPS I'll be happy. Not sure I trust my dealer Ha Ha think I might try another garage.

Thanks for all the advice!!!!