Predator 212cc carb troubleshooting

[JiveMagician]

Hey guys, to keep it simple I have a predator 212cc. Only mods I've done to it are a high flowing exhaust and a Mikuni carb. The engine itself is brand new and ran everytime I pulled the starting rope. However, after install the Mikuni, it will not run. It won't even sputter as if it was starved for gas. I've been attempting to fix it for 2 weeks, and so far nothing. Any of you guys got any clue as to what is going on? Also, it is getting spark, gas, and air. Compression is fine.

 

[Denny]

Try opening the throttle when you are trying to start it and hold it open,


Denny

 

[Hellion]

Adding to what Denny said, your idle speed might be set too low.

 

[JiveMagician]

So I tried the throttle trick, and it worked sorta. I have to have it at WOT for it to start, and when I let go it stalls. I'm guessing this means that my idle screw was set all the way in at the factory?

 

[Hellion]

Could be. Sounds about right for all adjustments to be set at factory 'zero' so they don't back out and come loose during shipment.

WOT though?
Sounds like you might not have enough FUEL going in at idle...

 

[JiveMagician]

Ill back out the idle screw and mess around with the needle adjustment in the slider. I will say that I have noticed that fuel comes out of the overflow tube on the bowl so I don't think the carb/engine is lacking fuel.

 

[Flyinhillbilly]

If you’re getting fuel out of the overflow, then there’s a good chance that you have a piece of trash in the needle and seat causing it to flood. Does it run rough when you get it to start at full throttle?

 

[JiveMagician]

Sorry for the late reply, but no. It runs really well actually. No back fire/misfire.

 

[bob58o]

Could be. Sounds about right for all adjustments to be set at factory 'zero' so they don't back out and come loose during shipment.

In order to prevent a screw from coming loose and backing out, it would be turned in. On every carb I’ve played around with, turning the idle speed screw in will raise the idle speed.

But it does sound like the idle speed needs to be turned up.