"but the RPM's go up and down with the governor swinging back and forth" ========================================================== I agree with the advise from Baymee and NW. Find the model, type and code - which is probably on the top engine cover - and use the link provide to look at the parts breakdown. http://www.commercialpower.com/display/router.asp?DocID=22742 If the engine continues to run up and down (surge), the carburetor may be running too lean. In this event, the carburetor would probably need to be disassembled for cleaning. Here is a link that might be useful: briggs commercial power

Walt I drained the oil last night and it was clean with no signs of any fragments. I also did try and set the governor shaft at the farthest most clockwise setting and setting the governor arm at full throttle. By doing so the engine would not start, it always starts on the 1st or second pull. I then moved the governor shaft and arm to the farthest counter clockwise position and it started on the first pull, however, still racing. In desperation, I tried moving the governor shaft to the counter clockwise position and adjusted the governor arm so that it was mid throttle, same result, races. Then tried setting it at it's slowest throttle speed, still races. One thing is for sure, the governor shaft must be in the counter clockwise position, otherwise it would race even faster. The spring and linkage all work freely so I'm at my wits end of what is causing this. I suspect it's internal governor issues. Fisher40037 Thanks for your suggestion regarding the throttle plate screw, pulled the carb and everything is fine.

Bruce, being a diesel mechanic, you may have a dial indicator that you can set up to measure the lift of the cam. These engines have something of a reputation/history for wiping out cam lobes. It would be a stretch to think a cam lobe would wipe out "instantaneously" so this step may be just to assure the cam is in good shape and eliminate that as a possibility. The symptoms of exhaust and compression coming back through the intake valve would point toward the exhaust cam lobe being the culprit. It's not that the engine would be firing at the wrong time, it's that if the exhaust lobe is gone, the combustion chamber is not purging on the exhaust stroke. That leaves a significant volume of "compression and exhaust" remaining in the CC which will rush out through the intake valve as it opens for the next intake stroke. Measure at each rocker arm/push rod position and see how much lift the cam is providing and compare the intake lift to the exhaust. The values should be nearly identical. Briggs does not give a specification as to actual lift, instead they give a physical dimension size of the lobes to be determined using a micrometer after the camshaft is removed. That is all fine and good for checking during rebuild but does not help when diagnosing on an intact engine. Best you can do without tear down is the measure the lift of each and compare the two values.

Thanks for the additional comments everyone. I replaced plug and ensured correct gap. I will check the ignition coil if when I put the carburetor back on, it still demonstrates the same issues. I also replaced the diaphragm in the carburetor. Since I last posted, I took the caruburetor off the engine and thoroughly cleaned it again with compressed air and carb cleaner. When I took the gas tank off, the small fuel well at top of tank was full (the main tank was not full), so that demonstrates to me that the pump/diphragm system is getting fuel adequately to the small well. This time, I took the welch plug off the idle mixing well and shot compressed air through the tiny orifices that deliver air/gas idle mixture to the throat. I blew compressed air through each hole and felt the air come out the throat so I know they are unclogged. I also put compressed air down the idle air blead that goes from the mixing chamber to the throat. I removed the idle mix needle and put carb cleaner down the orifice that brings fuel form the needle valve to the mixing chamber and from the needle valve down through the short pickup tube. I am convinced now that the entire idle air/fuel deliver system is clean. Now I'm waiting for the mail to get my new welch plug so I can put it back over the idle mixing well and reinstall the carubetor. I will reassemble and start back up after I get my welch plug. If it demonstrates same behavior, I'll take a few minutes and scream and then proceed with the next suggestions which I believe is air leak past the carburetor and ignition coil fail when hot. Thanks again for your suggestions.