Carb "Hunts"

[Tankman 3,523]

Guess I'm more mechanical than engine.

414-8 14 hp Kohler carburetor "hunts", doesn't like low RPM's.

Tried GUNK spray carb cleaner, all's clean.

Tried the initial settings, 2-1/2 turns out, then WOW, have to open up the idle

and main screws perhaps 1-1/2 turns.

If I try a low idle, like my happy two 12 hp Kohler engines, the 14 hp will stall out.

Any ideas? Any hope adjusting the carb on the block?

[MarkPalmer 81]

The hunting is almost always a main jet blockage problem. Pull the needles out and make sure they are completely free of any varnish, and that the tiny holes in the long main needle are not clogged and can pass air. I carefully clean the ends of both the main and idle needle with very fine 800 grit emery paper to remove any varnish, then spray them with carb cleaner and dry. I also spray carb cleaner down the holes with the needles removed then re-assemble and do the initial settings and tune once engine is running. This should clear up any carb jet related issues.

-Mark-

[Tankman 3,523]

Thanks Mark. I'll get both needles and their seats clean and report back.

[Coadster32 793]

I agree with Mark, and I'd definatly start there. Sometimes those really small holes on the needle get plugged up.

. I've also seen a carb hunt because of a makeshift govenor spring.

[squonk 43,899]

Hows the throttle shaft? If it's worn and letting air through it will keep changing the mixture depending on how much it's vibrating back and forth. Letting in too much air and then closing it off.

[rmaynard 16,343]

Also, when cleaning the main jet needle, the tube is hollow. So just cleaning the tiny holes isn't good enough. The tube must be able to pass air from the top holes, through the inside of the tube to the bottom ones.