small engine: carburator confusion

First make sure the gas cap vent hole is open (not clogged). If that doesn't do it, blow air back thru the fuel line to the tank. There is a small filter in the tank, you may be able to use needle nose pliers and pull the tube out of the tank and check the filter that is at the end of the tube.

Hank

Did you ever leave gas in it like overwinter, My fs 36 got like that so I had the carb cleaned after leaving gas in it one winter.

Jet plugged.

I wondered a little about that. But, during its brief burst of life, it seems to have full power, and good throttle response. Would you still think the jet?

the crab is fouled......usually from leaving gas in the unit

BTDT with a Husqvrana chain saw...exhibited the the same behavior.

not getting gas, runs that short spurt on gas "primed" in

clean the carb, it'll work

I learned this the hard way, paid to have the card "rebuilt"

cheers Bob

Sure sounds like it. Carbs usually have several jets. One for idle, one for midrange and sometimes more. Your mid-range jet is very likely clogged. Enough gas dribbles past it to make the engine rev for 10-15 seconds, and then it starves. It's the same performance you would get by sqirting some ether in the throat and then starting it. As soon as the ether burns of, the motor dies.

Your carb has 2 jets. One is the pilot jet which controls rpm's from idle to 1/3 throttle, the other is the main jet which controls rpm's from 1/3 to full throttle.

If it runs for 10-15 seconds, we know you have compression and spark, and spark timing. Therefore, the only thing left to check is Air/fuel mixture. Most motors won't run 10 -15 seconds from fuel delivered by the prime bulb, but could I guess. Most only run 3-5 seconds at best.

Have you tried adjusting the needle jet screws (one is for the pilot, one is for the mani)?

If you have checked the gas cap and lines going to the carb and are sure they are clear of any debris, then try adjusting the needle jets. To start, screw them in all the way, then back out 2 turns, start it up and then adjust the pilot jet at idle speed and the main jet at full throttle.

Hank

I just flushed it with Gumout, and that seemed to do it. Thanks to all.