A buddy of mine at work. Spring comes and get favors-like tinkering anyway. This is a 4-cycle mtd product. Came to me a week or so ago and died on him last year and would not start. Pulled apart and saw nothing wrong then read someone about a stuck valve and needs regular adjustment. Anyway new plug, exhaust valve looked stuck. Loosened, set at speck per owner manual, new plug and voila. Changed his oil, cleaned filter. Two pulls ran for 10 mins good to go. Ran again at work and still ok. Used on weekend ok. Used next day and sucker died while running and wont start.

He's bringing it in again tomorrow. Who has ideas? Thanks.

Check the valve again, if it's stuck, could be the fuel causing the problem, or the oil may need to be changed and make sure the cooling fins are not plugged up with debris. Could be something else entirely, really need to have a look at it first before jumping to any conclusions.

Update. Played with this in lot after lunch as he brought back in. Valve is still set at spec. Spark is good. It kicks but only for a second and i am guessing an intake/fuel problem. This carb has a pseudo-choke on it that closes the air intake. Manual states not to close it unless under 40 degrees. Well it keeps going longer when this is fully closed but still dies after about 5 seconds. so it is not getting fuel correctly. My 2 cycle echo had an issue with fuel lines before at 13 years old. Looks like only 2 lines on this. one from filter line to carb and a return/breather line from carb to tank. echo had 2 lines and a grommet. no echo-type grommet and the return line just sticks in the tank. unit is only 1.5-2 years old and lines look fine look fine. dont know if this could be it. return line gets lots bubbles while pumping primer bulb. carb is zama 753-04296. any typical problems with these? thoughts here? thanks