Hello,
New to the forum and looking for some help.

I have a 2009 Honda Metropolitan and I'm having issues with high rpm after I release the throttle.
The carb is a generic aftermarket carb that came on the scoot when I bought it from the previous owner. It also has an aftermarket air intake from RuckShop.
Carb has 35 slow jet and 85 main jet, along with 1mm shim.
I've taken the carb apart fully multiple times and cleaned and reassembled to make sure slide and needle isn't sticking or jets are gummed up or anything.
I've also done the ECM reset as specified in the manual, and one thing I noticed was manual says headlight is supposed to light back up, but in this case it does not.
Battery is brand new.
I keep adjusting the air fuel mix screw and idle screw, thinking it has to do with those somehow, but can't get it fixed.
When engine is warm I adjust the air fuel mix screw to highest rpm, and then adjust idle screw to get close to 2000rpm.
Scoot runs well once adjusted, but once I rev over 6000-7000ish rpm and let go of the throttle, the rpms won't drop below 3000rpm.
When it's stuck at 3000+ rpm if I adjust idle screw back down to 2000ish and turn it off it won't start without giving it throttle.
If I turn it off when its stuck above 3000rpm, and then I start it back up, it starts right up and idles around 2000ish, where I set it.

Any ideas on what it might be?

Thanks in advance, and looking forward to discussions on the forum here!

 

did you manage to fix this? I’m having the same issue. I just let it idle high. But I’m worried that there might be more wear happening in the trans parts. Band, rollers, clutch etc. especially at a red light. Let me know what you did to fix it. I try to keep my RPM around 2000-2400 after warm up at idle. Maybe my tach is cheap.

 

This may help.
Pop the hood and crank the car.
Track down your intake hoses and spray one at a time with wd-40.
If the idle shoots up that hose is leaking.
Replace the hose.
Repeat until all hoses have been sprayed.

 

Appreciate the response, this is for a Honda Ruckus Scooter. We both have one single hose that goes from the carb to the filter. At least for me, I tightened the carb side with the clamp that was provided by the kit. (The ruck shop) the other side where the air filter meets the hose has a pvc pipe that is fitted or maybe glued? So the hose to pvc pipe is fixed. Finally, the filter mount to pvc has a hose clamp as well. Tight fit. It does come with another filter that replaces the hose coming out on the side by the electric idle sensor? That was also tight fit with hose clamp. I even went as far as setting a filter on the pcv valve on top of the radiator that is mounted on frame.

I’ll also mention that I have a decompressor tube kit. Could that be the issue?

i also checked the trans final gear oil, and it had nothing! Rode roughly 60 miles with it like this. Flushed it out 3-4 times and I can see green/shiny metal?, Residue coming out. Hoping I don’t have to change gears.

 

Hey did you ever figure it out? Cause mine does the same thing?

 

Did you get it figured out ? I've done the exact same thing as you and am having the exact same issue.

 

Did Anyone have any luck getting this resolved? I am having the exact same issue, even experience the same issue when trying to do the ECM relearn. Have another Ruck that the relearn works fine on, but this one I can’t get the light to flash as it should, I do hear the fuel pump turn on, so I’m not sure if the relearn works…. In any case I still experience the issue where the throttle “Hangs” when I release it, it does typically eventually drop, sometimes I can get it to drop quicker by hitting the brake (while on kickstand obviously, trying to troubleshoot).
Thanks!