82 fb which has just had the fuel pump and filter replaced.Starts and runs after a few miles it won't run under 3500 rpm if it goes under even with the pedal to the floor it slowly dies.Today I drove it 50 miles at 65-70 mph slowed down coming into town and it dies.Changed the plugs, checked fuel at carb which was ok and after it sat 3/4 hr started ran shitty til above 3500 ran another 50 miles died and came home on the tow rope. Temperature normal. Will check the coils,igniters and replace the dizzy cap,rotor and wires when the local parts store gets em in. This has me puzzled. Any ideas

 

Sounds like too little fuel or Compresion issues.

I'm not too familiar with carb terminology or specific anatomy but double check the jets that are responsible for low rpm fuel delivery as they might not be doing their job very well anymore.



Reason I say compression is because engines with low compression gradually build it as rpms increase and that reults in crappy low rpm performance and good high rpm performance.

check engine compression and let us know the results.

 

Start by confirming that you have spark on both the leading and trailing spark plugs.

If that checks out, then you are probably looking at a carb rebuild. This will cost about 30 bucks for the kit, and as long as you can follow instructions you can do it in a few hours. Just be careful not to lose any of the small parts.

You can also find a lot of good info on these carbs at www.sterlingmetalworks.com

One other thing, a can of Seafoam in the gas tank would be a good idea. This won't fix your problem, but should be done every month or so anyway to prevent clogging the apex seals in the motor with carbon.

Good luck.




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