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Small engine running problem

I picked up a clean 4 hp Craftsman engine. It starts and runs fine after pressing the bulb primer 5 times, but stops after that gas is gone. If I keep pressing the bulb, it keeps running.

I removed the center bolt from the bottom of the float bowl, the bolt is also the main jet. It had some crud in the cross holes, so I cleaned them and ran a #75 drill into the jet to clear it. I also ran it through the tube in the carb. No change.

I then discovered that if I keep the bulb pressed in it runs fine, ie, I do not need to keep pumping it.

Reply to
DT
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Is the bulb leaking air except when you cover the leak with your finger?

Pete Keillor

Reply to
Pete Keillor

Hah! I was thinking "air leak", but I couldn't make that consistent with everything working when he had the bulb pressed in.

It may not be a leak in the part of the bulb that you cover with your finger -- it could be a split around the edge, that you compress when you push the bulb in. In fact, that may be more likely -- those bulbs flex the most right at the base, that's where you'd expect one to split from over use or from age.

Reply to
Tim Wescott

Sounds like a Tecumsch I have on my Craftsman high wheeler. Mine is kept where it is very hot [90 to 100] on most summer days and very dry. Any thing rubber that is under stress lasts but a few years. My advise, get a parts breakdown and order all new rubber parts. I just replaced the smog tube and the 'O' ring on the float bowl. This reminds me to order the a new bulb next time I order part from that CS Co [Sears that is].

CP

Reply to
Pilgrim

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Reply to
JR North

Upon further thinking, if this engine is equipped with a smog system check the short hose from it to the carb. If it is shot you may be losing all your vacuum to suck in the gas. If it is a horizontal it may be hidden under the flywheel.

CP

Reply to
Pilgrim

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