Runs bad cold

[Bob1100RTC]

My 07 RT (6200 miles) runs extremely bad until it reaches full operating temperature. When started cold it doesn't want to take any throttle, sometimes stalling when the throttle is opened. Today I started the engine,it ran for about 20 seconds,I blipped the throttle and it backfired thru the air box and stalled. It runs fine when hot. No surging,good throttle response. I set the valves 200 miles ago and they were within .002 of spec. No difference after the adjustment. I'm thinking a temperature sensor or a bad secondary coil. Before I start getting into checking everything, I was wondering if anyone here has run into this. Thanks.

[marchyman]

I set the valves 200 miles ago and they were within .002 of spec.

Inch or mm? If inches you are 33% off on the intake and 17% off on the exhaust, not close at all!

[Bob1100RTC]

Inch

[andrewsi]

If you're measuring the gap with inch feelers, a .002" feeler is .0508mm, so that's quite a lot of variability ("within .002") when the intake valve spec is .15mm and exhaust .30mm.

I guess my question is how do you know it's within .002" if you were using inch feelers in the first place? Do you have a .00591 inch feeler for the intake valves and a .0118 for the exhaust valves? I'm not trying to be snarky, I just want to understand how you were measuring the gap in the first place.

To be honest, I don't know if being off to that degree on the valve clearance is enough to fully explain the cold engine behavior you're seeing. Certainly seems prudent to make sure they're actually set to spec. The next question, after taking care of that, is whether you synced the throttle bodies after adjusting the valves back at 6k? That's something I'd take a look at also - make sure there is still the appropriate amount of throttle cable play on both sides, and that the vacuum is properly synced.

[Semper_Fi]

To make my life easier during the valve adjust I bought the feeler gauges from my dealer, I only use a standard feeler set to check the gap on the rocker arm.

+1 with what Andrewsi said.

In winter riding here in New England (and it was in the 20's to low 30's) the bike would be sluggish at intial start up until warmed up but never during current temps we are seeing now.

I would double check everything as the other folks have mentioned.

[mneblett]

My 07 RT (6200 miles) runs extremely bad until it reaches full operating temperature. When started cold it doesn't want to take any throttle, sometimes stalling when the throttle is opened. Today I started the engine,it ran for about 20 seconds,I blipped the throttle and it backfired thru the air box and stalled. It runs fine when hot. No surging,good throttle response. I set the valves 200 miles ago and they were within .002 of spec. No difference after the adjustment. I'm thinking a temperature sensor or a bad secondary coil. Before I start getting into checking everything, I was wondering if anyone here has run into this. Thanks.
Those are all symptoms of running extremely lean -- as if the computer does not realize the bike is cold, and is not enriching the fuel injection to provide for cold starting/warm up. My first thought is to start checking temperature sensor wiring/connections, but my second thought is it will likely be easier/faster to just have the dealer put it on the computer to report any sensor fault codes.

[Bob1100RTC]

I have a complete set of snap-on feeler guages. I used a bigger IE: 012 inch to check the clearance before I adjusted the valve. I have been a master mechanic at a Chrysler dealer for 25 years. I have set valves on everything from ford flatheads to chrysler hemis to bmw oil and hexheads. I think that they are set to spec. And as I said there was no difference before and after the adjustment. I will take it to the dealer after I have determined whats wrong as its still under warranty.

[Bob1100RTC]

No need to go to the dealer. Bike's fixed.

[andrewsi]

Great! For those of us who were interested: What did you ultimately determine the problem was?

[Semper_Fi]

great! For those of us who were interested: What did you ultimately determine the problem was?

+1

[Bob1100RTC]

When I got the bike it ran phenominal. Took it for the 600 mile service and it never ran good from that time on. That said, I ballanced the throttle bodys per Don Ellenbergers article. The first thing I found was there was no play in the right side throttle cable. I had to back off the adjuster 3/4 to to achieve a minimal amount of play (I checked to make shure both ends of each cable were seated fully first) I backed the left side adjuster off an equal amount even though it had freeplay to try to achieve a base line. I did a balance at 2500 and 4000 using my homemade manomometer. It was way off to start. Rode the bike about 5 miles and came back and fine tuned 2 times. Not only does it run fine cold but its as smooth as new when warmed up.

[andrewsi]

Excellent! Glad to hear it was as simple as getting the throttle synced properly. Of course, now the question is why can't the service department at your dealer do a simple throttle body sync correctly? I'd definitely bring it to their attention.

[Polarbear]

Huge question mark about your dealer, huh? Twin Max sales boosted here:). I carry one in my saddlebag and it lives there. Even so, the TBs rarely need adjusted, once set right. Randy:thumb

[deilenberger]

Huge question mark about your dealer, huh? Twin Max sales boosted here:). I carry one in my saddlebag and it lives there. Even so, the TBs rarely need adjusted, once set right. Randy:thumbI'll agree on the TB's rarely needing adjustment. I did adjust mine - just to make sure what I was writing in the DIY was correct - but the TB's didn't need it, and when I was done it was back where it was when I started.

I think BMW got the throttle-cable setup right with the R12/hexhead engine. Unless something really odd happens, I can't see them needing adjustment for a long long time.