2008 R3 15000 miles starts bucking while crusing at all speeds,

Lucky Lou said:

Can you expand on "starts bucking while crusing at all speeds"

Yes, when crusing at 55MPH, or any speed when not accelerating, the bike cuts in/out like a loose plug wire, loose batt connection. As soon as I open the throttle, she accelerates fine. It gets so bad,You want both hands on the handle bar at all times! Thank you.

Click to expand...

Sounds like a TPS (Throttle Position Sensor) problem. When the throttle isn't moving the signal goes to idle, then back to normal. Replace the TPS (or clean the contacts) and see if the problem persists.

Tha battery is an AGM (Acid Glass Mat) so it doesn't have a normal overflow issue like lead/acid wet cell batteries. The sulphur smell maybe the battery, but unlikely, especially if the bike starts and idles fine. May have to look elsewhere (like the exhaust) for that one.

Cleaning the crank angle sensor is a 5 minute job (at most). Single screw holds it in and has an O-ring for sealing. It's located on the bottom of the engine toward the back (oddly enough it has a wire coming out of it). Pull it, clean it and replace. See if it runs any better.

Thank you.
I will clean the crank angle sensor and check the TPS contacts.
Lucky Lou

LI NY

CHECK the battery connections. My R3 came with the bolts holding the wires on only by the bolt threads digging into the lead posts rather than the threaded floating blocks which really hold the wires firmly in place. The bolts are only just long enough and the blocks may need a little assistance to engage.

This WILL lead to earth faults and this can too lead to misfires and the smell of unburned fuel - especially if the cat has been removed. It could also lead to internal arcing in the battery - AGM's can dry out despite being officially sealed. If plates are NOT covered they die fast.

Thanks,
I had the a Battery Tender installed 3 years ago, tried to tighten already, got 1/2 turn on Hot lead, still has problem. I am going out today to double check all after I look up how to raise fuel tank up.
Lucky Lou