How hot is hot?

[pequeajim]

I have been experiencing the dreaded shutdown of my 25 hp Robin on a regular basis. I can mow for about 30 minutes and then the engine starts acting funny. I can keep it running by nursing the choke, but I think it is more than that?

Just for kicks, I put a temp gun on the cylinder heads, (not near the exhaust), and saw 270 degrees??

Thoughts?

[Phils]

Sorry I don't know the temps, and I have no excuse since I own an infrared thermometer.

You might want to add a fan... it stopped my vaporlock problems. I put mine on it's own toggle switch but will be changing that so it's on whenever the PT is running (although I'll probably leave the toggle switch but make so I can turn the fan off if a reason presents itself).

Phil

[cqaigy2]

I had a similar problem and ended up replacing fuel line, and fuel filter. Then i cleaned out the junk stuck in the fitting at the bottom of the fuel tank along with other junk in the tank. Then made my way to the carb and cleaned junk out of bowl, seat and channel for needle valve and last but not least, removed fuel shut-off of valve and cleaned the crap out of there. Haven't had any problems after all that.

I think the main culprit was the junk in the fuel shut-off valve, but im sure if i hadn't cleaned the rest it, would have just ended up right back at the fuel valve.