Yep, flooding. Be sure to turn the fuel off just a few minutes before finishing so it empties the fuel bowl, at least until you get it fixed. The flooding carb could contaminate the oil. If I were you I would cut to the chase and put a new carb on it. Then you can tinker with the old one at your leisure, maybe rebuild it and put it away for later. Sounds like a bad float.

Hi Guys Further update, IÂve had another hour with the mower this evening. Before attempting the cam cover removal I thought IÂd check the ignition timing. To do this I removed the red plastic cowling removed the plug and turned the engine by hand to TDC,inserted a thin metal rod to touch the top of the piston, and turned the engine to measure the down stroke (I make it approx 55mm). This gives 55mm X 2 =110 mm for the total down and upstroke of the piston, this is achieved in 360 degrees rotation of the crank. So a bit of maths (please correct me if IÂm wrong on this one) 360 degree of crank is 110mm piston movement 1 degree of crank = 110/360 piston movement =0.3mm piston movement 10 degree of crank = 110/360 x10 piston movement =3mm piston movement. ( I took 10 degrees as an optimum ignition timing for an engine). I marked a position on the started ring with fluorescent paint and marked TDC and 10 degrees before TCD and 10 degrees after TDC on the red plastic cowling adjacent to one of the slots in the cowling so I could strobe through it to the starter ring fluorescent mark. Re-attached the cowling connected the strobe and the engine ran with the timing showing about 10 degrees BTDC on this crude measurement. Increasing the engine speed did not alter the timing after the usual 20 seconds at about 2,000 - 2500 RPM the fault reoccurred but the ignition timing stayed constant until the engine stopped. I think this has eliminated ignition problems. Have I missed anything before removing the cam cover ? Cheers Pete

Well, I had a few minutes to check a few things over last night. Gotta love these things, engine shroud off, removed carb, float bowl....tools used, 1 screwdriver.. :-) So..float bowl was clean and crud-free, so signs of gunk in the needle valve, moves freely, etc. Cork float is all in one piece, and once the surface gas dried upp it doesn't seem saturated. The air vane moves freely, spring not broken. Throttle is held wide open, vane will close throttle, spring back to wide open, seems fine. I blew through the ports I could with the carb off....did NOT touch mixture screw (I assume it's the brass one sticking straight up behind the throttle through-shaft?) The mixture screw has not been touched at all (as long as I've had the mower, and it worked well since I've had it). Exhaust port is clear. Pulled the plug out, cleaned it up, a fair amount of wet sludge (from running so rich)..cleaned it up like new, reinstalled. So, that all checks out.....put everything back together, same issue. It's running rich to the point that you can tell it's sputtering when you move the air vane...it should rev up but it sputters instead, like it's way too rich. It ran a few minutes while I tried each direction on the click wheel (it changes the idle speed but it remains rich and doesn't want to rev up...sputters instead), and it left a big oily spot on the lawn under the exhaust port....so..yeah, rich... Also, it's spitting gas out the intake. Not a huge amount, but enough that it gets the air filter wet, and will fire drops into your eyes if you stick your head down there with the air filter off. LOL I didn't fiddle with the mixture screw. (Any time I fiddled with carb mixtures in the past ended with a trip to the small engine shop to have them fix what I screwed up.) If someone can confirm how many turns from bottom it should be, I'll pull it out in case there's a piece of dirt or something in it... As for the adjustment..it 'should' be good..it was never changed... So...recapping::: rich, will idle not too bad, but as soon as you cut any grass it just slows right down and stalls. Will not rev up any significant amount when moving the air vane..it wants to but just loads up with fuel and sputters instead. The issue came on slowly over 2-3 mowing sessions..it wasn't there all of a sudden...it came on slowly and got worse and worse over time. Feel free to toss the hints at me....thanks in advance!!

I would first suspect the carb is still gummed up. Get it running and raise the throttle and spary carb. cleaner directly into the carb venturi. It will only take about 1 or 2 second blast and the engine will lug down, let it gain rpms and do it again and again. I would also try to find the bowl vent and spray some carb. cleaner down that so it gets pulled through the carb. some. As for the valves I don't know if it a overhead valve engine or a flat head. If it overhead valve engine check the lash adjustment. if its a flat head remove the head and decarbonize the comb chamber or chambers.