Stuttering problems

[2006busa]

My beloved bike has developed some kind of a stuttering problem. it happens when I'm going about 70 in 3rd gear when i get on it pretty hard. it only does it for a split second but its enough to get my attention. i never noticed it at first so it might just be normal. my bike is a 2006 with 11,330miles and a full muzzy single sided exhaust, a PCIII and a TRE. all other engine parts are stock still.
any input???

 

[IG.]

Any work done recently? Does it happen going over a bump only, or pretty randomly? What about in 1st, 2nd, 4th - all the way to red line? Next time it happens pay attention to the rpm - does it drop to a certain rpm, or all the way to zero? When it happens, does it happen once (i.e. a single stutter), or a few times in sequence (i.e. a few stutters in a row)? Was the bike sitting for a long time? Did you recently start fueling at different place, or are you getting gas at some pop-and-mom gas station?

 

[2006busa]

no recent work has been done i put the exhaust and PC on at about 6K miles. the stutter isnt noticable in first and second. it only seems to happen in 3rd gear and it gets more noticable in 4 5 and 6. the rpms dont drop too much maybe like 100 if that. once u get past the hesitation it runs strong up to the redline. its more of a hesitation than a stutter. ive always put 93 octane or better in in.

 

[IG.]

OK. So, this does not look like an electrical issue, and looks more like fuel/air issue. Very puzzling. It's probably better wait for someone more knowledgable. However, it's always a good idea to eliminate simple things first. Try disconnecting PC, and see if this helps. Try putting '87 octane. When was the last time you looked at the plugs and they looked good? Also, did this problem progressed gradually, or appeared all of a sudden?

I bet the issue is present in 1st and 2nd, just not noticeable by the feel. The fact that it gets worse with higher gear because the taller the gear the more "difficult" for the engine is to pull the bike, so the same problem simply gets amplified.

Try gradually rising rpm while idling. Is there a hesitation at about the same rpm?

Another simple thing to check: lift the tank and check all air/fuel hoses carefully just to exclude the possibility of air leak, etc. See if any oil/sludge got on any electrical connectors.

Another crazy possibility is that at a certain rpm, a bad electrical connection somewhere gets worse because the connector resonates on the frequency at a certain rpm.

Otherwise, I'd suspect a map, plugs, injectors - not too sure though.

Another easy experiment. Put the bike on the rear stand, start up, and put in 3rd gear. See if that happens. If it doesn't happen while bike is on the stand, but does happen when you ride, then it's definitely fuel related because without the load the engine needs much less fuel to sustain the same rpm. So, if it's a fuel, again points to map, injectors, sparkplugs, maybe even fuel pump.

I jest re-read your original post and noticed important detail - you say it happens when you get on it hard. While you have the tank up, carefully examine your throttle cables for a possibility that there is some sort of binding which simply delays the cable movement. When was the last time you lubricated your throttle cable?

Try simple things first. There was a post recently how someone's idle became too high. In the end, it turned out a piece of something stuck on the throttle stop screw - all it took was a carefull look under the tank.

 

[brpo]

Sounds like fuel mapping based on strong perfomance in other rpm ranges and the fact that you describe it as happening in the same same gear and rpm range.

 

[rashad]

check your fuel filter... my bike did this ONLY at 8K rpms.. and it had gotten rust in there somehow.

 

[Spkrdctr]

Check the fuel filter BUT on all of these different motorcycle boards 99% of the time there is a problem, unhooking the PCIII, PCIV or PC5 usually fixes the problem. Everyone puts them on and some people have problems crop up down the road. Unhook it and your problem will most likely go away! Good Luck!

 

[Tufbusa]

Pull the plug on your PC! That would be my first move. If your stutter goes away, toss the PC and enjoy the ride!

 

[2006busa]

ill try some of these things out but, one that im not sure about is the PC... dont you need to run one if u have a FULL system?????

 

[Busacure]

reflash your stock ecu. look into it. looks like the new way to go. boostbysmith sells the interface harness boostbysmith.com - Home

 

[IG.]

ill try some of these things out but, one that im not sure about is the PC... dont you need to run one if u have a FULL system?????

It should still run. It may run a bit crappy, but you are doing it only once to see if this eliminates the problem.

I removed mine when I was troubleshooting another problem (engine would die momentarily), and it ran OK. I have a full Micron system. Remember doing simple things first, even if they seem unlikely.