idle issue By hawgheaven (Read 544 times)

[hawgheaven]

Hey I have a high performance Hoca carb I put on my bike. I understand how the idle screw works and the fuel and air mixture one works as well. I've checked all hoses on the bike and there are no leaks. The problem is it idles high as hell sometimes and other times it cuts off. Is there anything I could try to fix this?

[fflintstone]

Welcome to the forum ,hawgheaven,and tell us a little about your ride,model,type ,year..somebody here will be able to help--fflintstone

[hawgheaven]

Its on just a basic qmb139. It has a bbc, high performance crankshaft, high performance transmission as well. The carb specifications are listed here: Inner Diameter (intake): 26mm Outer Diameter (air filter mount): 42mm Electric Choke (plug style): 2-pin, male Accelerator Pump Main Jet: #105 Slow Jet: #35. Oh it also has a high performance Hoca head as well. Its a 2012 Honda ruckus clone.

[alleyoop]

Your main jet is way to big, do you realize that size comes with the 24mm carbs on the 150cc scoots. Try a #95 main also if that is a 26mm carb that is a lot of CARB for a 139QMB motor even bored out. You have to remember bigger carbs also have bigger passages and bigger Venturi and they suck in quite a bit of fuel and air.

The #35 Pilot may work but with the big main fuel is getting by the needle EVEN when it is all the way down so that is allowing fuel to get by the needle even at idle.
Alleyoop

[hawgheaven]

Maybe I should have put this in different context. The scooter runs great just not at idle speed. I do REALIZE that's a lot of carb for this engine, but that's specifically what this carb was designed to do. I've tried various different jets and the performance isn't there with the 95.

[alleyoop]

Ok, from your description that it idles high then starts to drop and dies that is a classic case of a overly rich condition on the low end. Change out the PILOT JET drop down on the pilot jet try a #32.
Alleyoop

[justbuggin2]

Alley is the carb guru

[hawgheaven]

Thanks for the help and how do I upload pictures I would like to put a few up.

[alleyoop]

the easiest is this one:
picturepush.com/host.php?image=10075950

Go to it and on the right you will see UPLOAD ANOTHER PICTURE in blue
1. CLick on it and it will come up with a BLANK entry to the right is says BROWSE.
2. Click on BROWSE and it will show your directories on your computer
3. click on whereever your picture or pictures are at and then click on the picture.
4. then Click on open and it will upload the picture for you.
5. Then go down to the 2 SET of LINKS and CLICK ON THE 2nd link in the box.
6. IT WILL TURN BLUE
7. RIGHT CLICK and then CLICK COPY
8. Then come here and RIGHT CLICK and CLICK ON PASTE.
Done

[hawgheaven]

These are my Bikes.

[alleyoop]

Very nice the ruckus type easy to work on
Alleyoop

Now how about a couple of shots of the carb area and hoses.