929 Idle Issues

[Snake358853]

hey guy i have a 2001 cbr929 and I am having issues with the idle in the mornings. my bike will start rough and idle a 1000 rpm and as the bike warms up the idle will gradually climb to 4000 rpm and stay there. i have been letting it warm up to about 180 degrees befor riding. can any give me ideas as to where to begin trouble shooting.

[07919Dave]

FPR, Injectors.....Take your pick. Start with the obvious first it the "choke" out?

[arctic954]

Depending on the mileage.... it could also be out of check valve clearances.... Though, I had 25,000 miles on my Honda 954 without any valve clearance changes.... it did run rough at that point though.

A Throttle body re-sync can also do wonders if it hasn't been done.

[brian]

Im gonna say FPR, but like dave said check the dumbest thing possible 1st choke. (we've all done it man or we wouldn't know)

Not to familiar with the inards of the 929 but do a google search on "Fuel pressure regulator test cbr 929" it's easy and free to test if you read up on it and easy to replace. I bet thats it, or do you have a Power commander or something like it? If so disconnect it and plug the wiring harness back together like honda had it. Ive seen those go spooky on several bikes.

Mabye someone more familiar with the 929 with chime in, I wonder if a simple vacuume leak would do this???

[arctic954]

Can't speak for the 929......my 954 did not have a choke. It was ECU controlled. I also haven't heard of FPR or PCIII-USB problems like what we've had on the 919's.

Assuming his airbox is sealed properly.......My bet is still on him needing a throttlebody re-sync because of higher mileage.

[Snake358853]

thanks guys really ill check that stuff out and let u all know how it goes. the bike does have 24450 miles on it

[HondaJim]

idle set too high?

[arctic954]

Originally Posted by Snake358853

thanks guys really ill check that stuff out and let u all know how it goes. the bike does have 24450 miles on it

.......it may or may not be 100% of the problem.....but if it hasn't been done with that mileage it will make a noticeable improvement at idle.

Google the Morgan Carb Tune. You use the same tool to sync a throttlebody as you do a carburetor. Simply put.....there is a vacuum nipple to each cylinder w/ an adjustment screw on the throttlebody linkage. All you have to do is align the vacuum readings of each cylinder at idle with the adjustment screws. Usually one of the cylinders is non-adjustable and the rest are synced to that cylinder. You perform the sync with the gas tank propped up, air box off, but with the AIT & IAP sensors reconnected. (the ECU still needs data from these). As you sync them....you have to keep adjusting the idle back to the recommended idle setting. (it's usually around 1,200-1,400 rpm).

In the end, your bike will run as smooth as butter.....

If it's still running bad after this? You have a bad sensor or vacuum leak somewhere.

[arctic954]

Word of note....... Before performing this......I would also recalibrate your throttle position sensor....(TPS)

If this is off.....your ecu thinks your at a different throttle opening and can make the bike run like crap.....

[Bigdaa]

What is the exhaust/tuning config? Stock?
Has it had valve check ups?
1st thing I'd try is compression check.

[07919Dave]

Any update with this?