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Bike running rough

3 posts · Started by TimR · 16 Apr 2018

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I just bit the bullet and got my 990 serviced, including valve check. The bike seemed fine afterwards and at the weekend I headed into North Wales for a ride.

Prior to this (2 months ago), I’d had problems with reg/rec which were resolved by fitting a MOSFET unit, but I don’t think this problem is electrics-related.

After about 100 miles (and probably 200 in total since the service) the bike started to behave strangely. I noticed revs were high and hunting in neutral at a standstill – up to about 1800 rpm. Then at around 3000rpm in the first few gears, on a neutral/light throttle the bike started to hesitate and run rough. This then spread up to about 5000rpm. The next time I stopped, the revs rose in neutral to 3000rpm. I got home OK, the bike didn’t stall and when turned off, it restarted without any trouble. There are no warning lights showing.

Yesterday I took the tank off to check there were no trapped pipes or cables – all seemed OK, the MH airbox was properly seated/secured and the rubber boots looked OK. Of course, when I put it back together and took it for a quick test ride, it didn’t show the problems. I guess it needs to be ridden for a longer time/distance to show the problem again.

I phoned the bike place that serviced it and they’ve said to bring it back in to have a look, which I am planning to do later this week. The mechanic said he thought it sounded throttle body related.

I have searched but can’t find anything to point me in a particular direction. Anyone experienced these symptoms?
The hesitating and the rising idle (to 3ktpm) i've had as well, on my bike it was the TPS... mine was broken so I replaced it and set it to the correct values and the problem was solved.
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