18 replies to this topic

[Rustysteele]

A good way to see if the valve clearances are too tight is to run it til it gets hot and stops. Check the compression then, if it has compression, the valves aren`t staying open.

[gardentractornut]

I've also seen a blown head gasket act like that , run fine till engine heats up and then sputter and lose power and die after 10 to 15 minutes  . Usually accompanied by a little black smoke right before they die . A quick check for oily residue around the head bolts will tell you if its got a blown head gasket . I've also seen a sticky exhaust valve cause similar issue if there is carbon buildup on it .

Same here, check the plug before and after it heats up. If it's oily then clean it off and try running it again. Happened to me and after a HG replacement she runs great!

[chieffan]

Got it up on the ramps to the table this morning. Found a bad connection at the coil going to the points. Moved it a couple times and it broke off. don't think that was the whole problem as it still had a connection. Removed the high speed needle and seat at the bottom of the carb. It ran out about a quart of gas with no problem. A heck of a lot faster than that engine could possibly burn it. I did not believe it was the valve clearance as it started suddenly, not a gradual thing so didn't get into them. Checked the fuel tank cap, which is not original. The waxy cardboard seal inside the cap had a tiny hole in the center. I took a small drill that would fit through the hole in the metal part of the cap, set the cap on a dowel and drilled the cardboard hole out. Moved the spring on the governor link to the 4th hole down from the 5th hole. Looked a lot of other things over and it all looked good to go. Fired it up this evening in 85° temps and started mowing. It ran for close to an hour and never missed a beat. I felt it was a fuel problem all along and I am 99% sure that the cardboard seal inside that fuel cap was swelling when it got fuel soaked and shut off the air supply to the tank and by enlarging that hole the tank could breath and the engine got the fuel it needed. Such a simple little thing that can cause a ton of headaches. On to the next problem, what ever that may be. going to an auction tomorrow that has a Super RAM listed with a B&S engine. Hoping to grab that for a song and dance. Thanks for all the input and suggestions on this problem.

[gardentractornut]

Glad you got it fixed!