Running pig rich...

[Mrx2002]

Okay i have been having issues with my scoot and WOT it just won't do it. Replaced the spark plug ran the scoot around the block still won't run past half throttle! Pulled the plug out to find this...



Now i have a serious issue because with the engine running i can turn the air/fuel adjuster screw all the way in and it keeps running. If the screw is pulled back out to where it should be WOT on the stand sounds VERY choppy and there is lots of black smoke coming from the exhaust. The elec choke is working like it should be i pulled that out the body of the choke was warm and as it started cooling off the needle retracted. Im about to say screw it and get another carb....

[FrankenMech]

What is the fuel level in the bowl?

Is there a leak in a diaphragm somewhere?

[Mrx2002]

Nov 26, 2014 13:38:10 GMT -5 FrankenMech said:

What is the fuel level in the bowl?

Is there a leak in a diaphragm somewhere?

The top diaphragm looks great i'm not sure on the level of fuel in the bowl ill check that tomorrow. Im also going to look very hard for cracks something is leaking fuel i know with the air/fuel adjuster screw in all the way the engine should stall but it keeps running. 

[FrankenMech]

Check the vacuum hoses for gas. A leak in a petcock or pump diaphragm can add extra fuel.

[niz76]

A/f mixture screw shouldn't have an effect on WOT. Adjust the screw so you have good idle and throttle response to 1/4 throttle and change the Main Jet for tuning WOT. (the needle-along with MJ tunes mid-throttle)The airbox snorkel can be a good tuning tool- if you think you're running rich, take the snorkel out which lets more air in and leans the mixture- if it runs better then you can use that as a clue to go leaner with the Main Jet...

[Mrx2002]

Well i was about to get another carb when i thought to myself pull the carb apart one more time and see if i can see anything wrong. The damn main jet insert was sitting on the bottom of the carb! Screwed it back in and omg the scoots running great. The spark plug definitely needed to be changed because i hit a new top speed today 48 Mph! Thanks for all the help you guys! Im so glad it was something simple!!

[FrankenMech]

Good to hear it wasn't anything major.

If that jet keeps falling out a tiny divot in the jet threads will usually tighten it up enough to keep vibration from loosening it.

[Mrx2002]

Nov 28, 2014 19:37:23 GMT -5 FrankenMech said:

Good to hear it wasn't anything major.

If that jet keeps falling out a tiny divot in the jet threads will usually tighten it up enough to keep vibration from loosening it.

Okay ill keep that in mind! Thanks for the tip man!