in bind with grandkids

[Piddler]

The grandkids are in for a few days and were looking foreword to riding the go karts. As luck would have it both of them are down. One has a B&S 3 1/2 HP engine model 91212 type OR1 01. It will not start without a little shot of carb cleaner or gas dumped it the carb. When it does start it will not accelerate as it should. This is an old go kart and there has been some interesting things done with the linkage and governor. I took the carburetor apart and cleaned it. The diaphragm looks good and all the orifices seem to be clean.

I can move the throttle butterfly to advance the speed but it still will not rev up. I am not a professional but I have worked on small engines for a while and this one is driving me crazy.

The kids are only going to be here a few days and I would really like to get these things going. I live in a small town and I will have to order any part that I need.
I will post I Tecumseh forum for help on the other one.

Thanks in advance, Pete

 

[ILENGINE]

Your symptoms are indicating a fuel problem either dirt in the carb restricting a jet, stale fuel would be the most likely culprits. Those old briggs are also bad at floating the intake valves so that could also be part of the problem. Meaning the valves won't close completely.