What you all think?

I recently built a 3 horse for my mini bike and since the first time I started it I have to pull it atheist 4 to 7 times before it'll cold start and stay running. Once it starts its a beast and will start back up quickly while warm. First pull it'll fire but die 3 or 4 more pulls nothing then it ll fire and die, one more pull and it'll start as it should. What did I miss? Thanks guys.
 
Choke?

Governor?

With governor, throttle blade is held wide open, giving more draw with choke closed.

Does it start easier with full tank of fuel?

Just some thoughts.
 
Choke?

Governor?

With governor, throttle blade is held wide open, giving more draw with choke closed.

Does it start easier with full tank of fuel?

Just some thoughts.
No choke sir. it's a raptor style carb. It has to be a diaphragm I'd say cause I don't use screens and I have looked in the metering holes. Another thing that is odd is it idles pretty high for the setting I am at. I have the screw all the way out not touching and it is idling like it should be if it was screwed in to normal position. I figured air leak but can't seem to find one
 
Last edited:
Must be a air leak somewhere . As Brian said pickup tubes , tank to carb seal , diaphragm . Even the little cup could have a hole or crack .
There used to be a cap with a pump too pressurize the tank .
 
If no screen, I would check pickup tube for blockage.

Stock 3 hp usually not have diaphragm. Shallower tank and draws directly from tank.

If is infact raptor style carb, check to see if bowl is holding fuel.
A crack there can cause problems.

Low fuel level there can act like getting air.
See adjusting float level for examples of changing jetting.
Make sure there is a gasket on mixture screw adapter.
 
Last edited:
Yeah I have two gaskets on everything it's a one quart tank but it is quite rare I think cause it is a diaphragm setup with two pick up holes instead of one like the others I have seen. This 3 horse is basically just a mini version of a raptor. It don't even have a governor hole or a points hole behind flywheel
 
The cup in the gas tank for the short tube may have a small leak in it, allowing the fuel to leak out when it’s sits for a while.
 
Found the issue. Feel dumb. I kept getting shocked when pulling the plug. Got to thinking and discovered my plug was not all the way in the boot. Wow now it starts first pull, way more power and I don't get shocked. Thanks guys
 
Sold a snowmobile because it wouldn't start good .
Always screwed the plugs in by hand because of it .
Guy said he tightened them an it starts right up ..
Ya never know .
 
Back
Top