Syclone

This might be a dumb question, but how high do you have your idle set? If you've got the adjustment screw pretty far in, that may be causing your rev issue. For reference, my idle is set at 900-1000.

Hawkrider

A lean running motor will cause the revs to hang for a moment before falling to idle. If you're running that lean then I suggest you rejet soon. Lean running causes hotter combustion temperatures which are hard on valves.

nuhawk

How about lubing the throttle cables. This made a huge difference for me on the Superhawk and now the VFR needs to be done. Take care of the most labor intensive parts first. They are the most likely to fail/need service.

8541Hawk

You could always try the "Old School" jet kit first. Pull the carbs and clean the jets. While you have the carbs off check the isolatoers to make sure they are in good condition. Then shim the needles up around .040-.080" you can find this size washer at radio shack or a place like that it's a #4 washer I believe but its been a while so I might be wrong with that number. Then open the pilot screw 1/4-1/2 of a turn. Put it all back together, sync the carbs, reset the TPS if you haven't done that yet and see how it works. The total cost is the price of the washers.

Syclone

It's a #4 washer, but no Radio Shack around here had em, so I found mine at Home Depot (any hardware store with bolt bins should have that small of a washer).

Shawker03

Thank you all for your suggestions. It gives me a place to start looking. I also need to correct myself a little bit. I stated that "1) When I roll off of the throttle, the engine speed does not drop immediately like I think it should. Example: letting off of the throttle and disengaging the clutch during braking-the engine speed will not drop for about 1-2 seconds." I watched it very closely today-when I roll off of the throttle, the RPMS "hang" right at 2k for 1-2 seconds before falling further-that happens every time.

Yes, my idle is set high, when warmed up, its around 1500, when its cold, it idles closer to 1200-1300. I couldn't tell you how lean the bike is or isn't running, I haven't tried to adjust that. My mechanic would have been the only one to touch that. (Pre-Paid Maintenance Plan-aka, buyer's remorse 101.)

Syclone

If it were me, I'd turn out the idle adjustment screw with the bike running warm until idle is around 1k and see if that helps your "hanging" problem, before tearing into carbs and jets.

Hawkrider

No, he needs to rejet, or at the very least turn your mixture screws out to around 2-2.5 turns from seated.

skokievtr

Someone mentioned lubing the cables: Remove the 2 screws holding the throttle "pod" together and dribble down the 2 cable sheaths DriSlide & pure machine oil, Dupont Multi-Purpose or some other good stuff WHILE working the throttle till it just runs out down by the carbs (put some paper towel down at the cable ends for easy clean up). I have found that despite using unscented "AuqaNet #3 Extra Super Hold" hair spray an as intall lube & glue for my gel "ProGrips" plus 2 rings of safety wire, the end of the rubber grip stretches and works down and rubs against the bar end weight. Result, engine speed hangs up a moment or 2 when throttle is released. Consequently I unconsciously push up the end of the grip at lights.

BTW, I set my engine speed at 1300~1400 at idle, which helps during heavy downshifts sort of like a poor man's back torque limiter.

Thumper

+1

Needs more fuel

Thumper

I have the Factory Pro kits in several of my bikes and friends bikes. I have always referenced this little troubleshooting sheet that comes in their kits. Very handy and notice this quote even related to bike being in neutral.

NOTE: A lean problem gets better as the engine heats up.
If the throttle is lightly "blipped" at idle, and the rpm "hangs up" before dropping to the set idle speed, and there are no intake leaks and the idle speed is set at less than 1000 rpm, the mixture screws are probably too lean: try 1/2 turn out, to richen mixture. Be sure there are no intake leaks and the idle speed is set at less than 1000 rpm!

http://www.factorypro.com/tech_tunin...m_engines.html

For what its worth i have the Jardine High Oval pipes, K&N filter, Factory Pro 4 degree ingnition advance, Pair system removed completely form the bike and the Factory Pro TI kit and mine is right in the sweet spot for the Fuel/Air Mixture ratio on the Dyno.

If you have the stock jetting you are lean.

48 pilots work well too including installing a rear emulsion tube into the front carb helps idling and surging as the front cylinder has a tendency to run richerr than the rear. The emulsion tubes are not the same front to rear.

From the Factroy Pro Web Site:

Emulsion Tubes

They are different - front to rear

The rear one is leaner at cruise than the front (as delivered)



For persistent over richness, you can use another rear emulsion tube to lean out the front cylinder. The higher holes delay the onset of fuel delivery. Diagnosed by the need to have the front fuel screw almost closed for best idle - That's a superb test for pilot jet size.

Best idle should be obtained between 1.5 and 3 turns out - if you have the correct size pilot jet and TPS adjusted to 500 ohms and you don't need a rear emu tube in the front - as some vtr's require -