Hello all, this is a model 170402, type 235201, it is mounted on a mighty mac chipper shredder. Durring the last use it seamed to be surging and required the choke to be slightly set, so I pulled the carb and cleaned ,now it will only run for 1 to 2 minutes (when it is running it runs strong), Have done the following :

1. pulled the carb off and cleaned, Sprayed with cleaner and compressed air
2. new plug
3. check fuel tank vent cap, (ran it without the cap on & still did the samething)
4. checked the fuel filter, remove the line from the carb side and put a can under the filter, then I opened the fuel shut off valve and fuel flowed just fine.
5. cleaned the fly wheel mag contact area.

Ok all whats next? Pull the carb back off and reclean, new coil?, replace the fuel filter?

Thanks for your time.
Bill

rebuild the carb, not take it apart slightly and clean it, but take the jets out and clean them well by taking the carb cleaner tube right to the holes. take the fuel bowl off and check that to make sure its not sinking by being full of fuel. and clean all the holes out with cleaner and just leave it be and slap it back on and try it then.

Can you explain this: This evening I went back out and before pulling the carb back off, I gave the rope a pull and it fired right off and is running like brand new. I let it run for over a half hour. So should I do anything to it or leave it go?

well you should see why it did what it did, mainly it could have been the cleaner but it could have been something else. oh and give the oil a good smell to make sure no gas is in it. just as a precaution in case straight gas ran.

Could be there was still some chunks of carbon in the combustion chamber from the earlier crappy running & the chunks would get on the spark plug causing it to die, could also be a coil about to crap out & opens as it heats up.