Running rich....????


I went on a group ride today...150 miles or so. The rider behind asked if I was running race fuel. Said they could smell my exhaust.

I was running 87 octane. I just recently switched to Mobil 1...about 1500 miles ago. 9800 on the bike right now. Pulled the air filter last week to give it a once over with the air gun.

I have noticed over the past month...a decrease of 5 mi/gal according to the indicator/computer.

The only thing I can maybe think is the plugs. Havn't checked them yet. Or some oil could be slipping by the rings...I hope not. Any other suggestions from the experts?

No, completely stock.

Do you think I could have something loose?

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no, just after market exhaust will cause smell, they are totally diffrent from the factory exhaust. thats why your bike will backfire when you let the throttle go on an after market exhasut & would not do it on a factory exhaust. did you change your ridig habet? like do you ride slow but you had to ride fast that day so you can catch up with the guys? cause if you ride slow your bike will build alot of carbon. so when you ride it hard on day you will burn all the carbon which it will cause your exhaust to smell.
may want to try some fuel injector cleaner like 44k for bikes...

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I'm having a similar problem. I checked my plugs, and they're carbon fouled (too rich).

I described the problem to a dealer mechanic, and he thinks it could be a couple of things. Have you seen your FI light come on? The mechanic indicated that the TPS (throttle position sensor) could be the problem, but this would usually generate an FI error. He also suggested that the atmosphereic pressure sensor could be the culprit, and it does NOT generate an FI error.

I'm taking the bike in tomorrow, and they're going to connect it to their diagnostics computer.

BTW, I swapped out the plugs with a higher temp, and the backfiring is lessened to some degree, but the bike is much smoother.

Good luck solving your problem.
Posting this in the event it helps/informs.

I took the bike to the dealer, he put the bike in dealer mode and no FI codes came up (hooray). However the TPS was set high. Got it back home and adjusted it. What a lame way of setting the stupid thing. Not very precise at all. There's only a single Torx tightening screw, so it's hard to get it just right.

Haven't been able to test it yet, but I'm hoping this fixes the problem.
Might be worth a trip to the dealer. Havn't had much time to mess with it...maybe this week.


Check your owners manual I think they recommend changing spark plugs at 7500 miles. If they have never been changed your over due.