Carb talk

[Chance M]

Why would someone drill out the idle needle seat? I talked to the guy that I got the new carb from. Told him my prob with my old carb. He said someone likely drilled it out, that is why I can't get it to stop running with rich idle but to high end is fine. I hadn't replied back and asked him why yet. Gonna do that tonight. What Ya'll think? Is it some kinda modification for power.? I think my old carb made the tractor run stronger...is this possible?

Chance

 

[rustred]

people do all kinds of things. you can install bigger main jets or drill them out, for power as in tractor pulling or as in
stock car racing. but who knows why the idle needle seat??? unless its the main jet your talking about.

 

[Andy Martin]

Thought you had an M. The idle needle seat is an air bleed, if the seat is drilled out, I would think you would have a lean idle mixture unless you could still screw it down tight. I really thought your problem was the missing idling jet, which has a small orifice. That is the tube that sticks out the top of the bottom half.

 

[Chance M]

That part is not on my old carb....and yes it is an M.

That is what the guy said....I'm gonna ask him to explain more. It is Dans carburetor out in California. I believe he is a member here aswell. And, I could be mistaken, maybe it is the actual idle passage/port?

 

[jeffcat]

Good golly NOOOO. Don't drill the idle jet cause you just screwed the carb. They are NOT fixable unless you change the whole top of the carb with a new top and try again dummy pat on the head. Main jets are done with finger number dills from the back of the jet and very very carefully. With a regular tractor you should never ever need to drill the jet if it is sized correctly. Turn the main jet needle out a couple of turns first.

 

[Chance M]

Indeed jeffcat