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Old 09-02-2012, 05:52 PM   #3081
Happy Wanderer
Day Dreaming.. .
Joined: Apr 2010
Location: Vancouver, BC
Oddometer: 207
Originally Posted by EKinOR View Post
OK, I have some performance related questions on my 2002 R1150GS. It has 42k miles and the valves were adjusted and TB sync done at 38k miles, along with an oil change. I put new Autolite 3923 plugs (.035 gap) in 1k miles ago.

1) It's hard starting when cold. It takes at least two 4 second cranks to get started, and sometimes three or four attempts. Once warm, it fires right up. What might be the cause of this?

2) After a cold start, I usually let it warm up to one, sometimes two bars. Invariably, the first time I accelerate on to the road, it stumbles and lags for a second, then "catches" and off we go. It does not do this when warm. Ideas on this? Is it related to #1?

3) I have the typical low RPM surge. I've played around with different configurations, including factory CCP, Steptoe jumper, no CCP, connected O2 sensor and disconnected O2 sensor. Right now, I'm running no CCP and the O2 sensor is disconnected, but it doesn't seem to help. I reset the Motronic by pulling the fuse for 5+ minutes, between each change. After I put the 3923 plugs in, it seemed to help some.

Other than these things, it runs great. Mileage, on E10, is between 36 and 41 MPG. Often, I'm fairly aggressive with the throttle, but It's better on the highway (as I would expect) I haven't been able to correlate a mileage difference with the various CCP/O2 combinations I've tried. Overall, the mileage seems a bit on the low side.

Lastly, if I roll off the throttle quickly, it decelerates hard. I believe this is caused by "overrun fuel cutoff." Can this be improved?

I'd love to fix the surging and increase the mileage, too. I have an Ice Air on order - will it help with any of the above issues?
If you don't have an IIce Air on the bike this thread is the wrong place to post your problem.
Moderator: Clean up on aisle 3!

- the correct gap for your plugs should be ,028 not .035 I believe. Don't re gap old plugs, they may break and wreak havoc.
- Have you cleaned the brass idle screws and the oriface they go into lately?
- How's your air filter? Clogged up with dirt and dust maybe?
- Who tuned the bike? If it was not you then you can't be sure the valves or the synch was done correctly.
- If the problem did not exist before you changed the plugs... start there! It's usually the last thing that got worked on that leads to the solution. Retrace steps methodically and change only one thing at a time.

- Oh and NO, The IceAir will not help with any of the issues you describe.
Happy Wanderer is offline