funny noise at turn of key

[trichiro]

Problem started when shipped bike from Florida to Colorado. At 5700 ft there is a backfire when I come off throttle downhill. I changed the plugs and put in a K@N air filter that allows max air flow. To get air filter cap back on I tilted rear gas tank up. As soon as I turned the key the normal sound of the fuel pump now sounds totally different and there is a noise while running the bike. The original problem got better but not fixed. 2003 R1150R 7800miles. Any thoughts?

[Slablog]

It sounds like the Motronic had adjusted to Florida elevation and once in Colorado it was running differently until the computer readjusted as you rode it around. You could have disconnected the battery then reconnected and then reset the Motronic by turning the throttle full open with just the switch on (not running).

When you lifted the tank, did you disconnect any fuel lines or hoses under the edge of the tank on the right side? The fuel pump is inside the tank and it should not have been disturbed at all by simply lifting the rear of the tank...unless you dislodged some settled 'gunk' or something and it got sucked up into the filter partially blocking it.

When was the last maintenance? You may want to take off the tank and check a few things, topping off the battery if its still the original lead acid variety.

Lots of info at www.r1150r.net

[ArthurKnowles]

I agree that resetting the motronic might be a good idea, but a backfire on decelleration isn't too unusual either. Particulalry if you do not close the throttle all the way.

At least my RT does this as do many many others.

[trichiro]

Funny, I went to start the bike this morning and the noise was gone. Who knows!! I will reset the motronic though. Thanks

[trichiro]

Hey, I reset the motronic and the bike purrs. I appreciate the advice.