This engine is on an Excel 2525 pressure washer.
Starts easily runs OK but surges up and down without developing full power. Cleaned carb twice with carb cleaner and air. Has no adjustments. Only fixed orifices. Used SS fishing leader to carefully probe the jets. Cleaner flows readily. Have not touched the gov. Do not believe it to be the problem. Springs are in good shape and still set to the #4 hole from the factory. Testing with fuel tank removed on long , new fuel line. I feel it has to be running lean but can't see why. Idles OK. Tries to respond to full throttle. Small amount of choke improves, not cures, the problem.
Any ideas?

Thanks

 

Post the engine Model, Type and Code usually found one the metal engine shroud just above the spark plug. Have a good one. Geo

 

Hey geogrubb. Thanks. The only numbers I can find on the engine shroud may or may not be what you ask for. They are 000505FD and
123435 0168E1. These were on the rear above the pump.
Hope this helps

 

I am not sure if your carb has metering holes at the base, however check the bowl nut, the holes if any should be at the base. Also sounds like an air leak, so while it it surging spray carb cleaner along the mating surfaces behind the carb and intake, if the engine changes tempo you have found the leak and can take the proper action. Have a good one. Geo

 

Thanks geogrubb. I did as you suggested and you are right on target. There is an air leak but seems to be around the throttle shaft not intake. Does that make sense? Know more when I have time to take it apart again. This engine couldn't have more than 30 hours on it. Of course the carb looks like a gutless wonder so not surprised. B&S upper management must be really proud of this one.

Thanks again, appreciate your help, hefe