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12S907 surging
- Thread starter kh0432
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Export threadWent back to check the valve clearance and realized I had the intake and exhaust adjusted wrong (got them mixed up). The exhaust was too tight and the intake too loose. Readjusted and same problem but it didn't seem like as much blow by coming out of the carburetor. Pulled the head off. Cylinder is like new with no scoring or ridge at the top. Pulled the valves and both seats are nice and shiny with no signs of burning or a seating problem. The thing that has me stumped is the fact that when it starts surging I can hold the governor spring and it will continue to run strong. It doesn't act like it's running out of gas. Even when the choke is fully open it will continue to run fine for a few minutes even under load before the surging starts. My other problem is I'm too hard headed to admit defeat. At least now that Maryland is on a shelter in place order I have plenty of time to play with it. I appreciate everyones help although I don't know what's meant by "Duh, ???????"
Thanks for clarifying your response. The head gasket was fine and I cleaned and lapped the valves anyway. The inside of this motor looks like it was hardly used. Wouldn’t you think if it were a fuel problem it would act up before running for 5 minutes? I even pulled off the screen in the bottom of the tank, stuck a rod through the nipple to make sure it was open and used a new 1/4” hose connected to the carburetor with no filter or shut off valve to make sure I had good fuel flow. If the governor was out of wack it shouldn’t run as long as it does before acting up. Also if the washer pump is changing the load the engine was designed for it shouldn’t run as strong as it does. This is driving me crazy?
Well I couldn't give up and finally fixed it. Never got the first engine to work right so I picked up a free mower (deck was rusted out) with a 125K02 engine. Cleaned the carb, got it running and it was fine on the mower. Took the engine off and had to shorten the crankshaft to bolt on the pump but got everything to fit. Started it up and it was surging just like before. Found a box of assorted springs in my basement and found one a little stiffer than the one on the governor. Put it on and now it works great under load and at idle. One thing I learned from this is that it's not worth it to make your own pressure washer‼