I have a tecumseh H60 on an Ariens tiller. I rebuilt the carb as the motor was running terribly (started the first pull!), but noticed that a lot of oil is coming through the rebreather, fouling the plug such that the motor loses spark. There's enough oil coming out that you can see it running down the side of the engine. I think the valve seals are shot. There are a lot of hours on this engine and it sits for long periods. Oil levels are fine.

Any suggestions on other strategies or helpful hints on replacing the valve guides? I've only done this on an old briggs vertical and gravely 5.5/6.5 motors.

-Motorhed.

coming through the breather into the carb through and onto the combustion chamber?? it may just need a new breather.

I was just brainstorming that a few minutes ago. I also talked to a friend I loaned it to (in exchange for an oil change) and he put the same stuff he uses in his push mower - 10W40. The manual says DO NOT USE SAE 10W40 (their caps). Dunno if this could have hurt anything, but before I pull the motor apart, I might try a qt of SAE 30 to see if that helps at all.

dunno, have you smelled the oil lately? had one man before with about the same problem with gas in the oil, not saying its your problem though, umm 10w-40 wouldn't have hurt it unless it was cheapo crap. hmm of course i've seen where people mistake the oil fill for gas or the oil filler for gas.

You may also have a bad breather.

Funny thing, but I emptied the motor of oil and replaced the 10W40 with SAE 30, and now no oil comes out of the rebreather! Don't fully understand why, but I'll bet that it was probably a little of the oil issue and a little of my testing out the rebreather by blowing air in/sucking air out of it.

The current issue that I am having is that I have a spark and can get a pop, but gas is just flying through the system and out the muffler. I have set the float to a lower position and tightened down the main jet, but this is still happening. Not sure why. The seat is oriented correctly and the needle is seating well when the float is high enough. Need to play around a bit, I guess.

I set the gap on the magnatron using a $1 bill and using a tester (one end in the plug wire and one grounded on the engine) I can verify that I have continuity and therefore SHOULD be getting spark. Plug is new and I have tried both old an new plugs. Anyone know how I can test magnetron performance? The "contacts" on both the flywheel and the magnatron are nice and clean.

either the magnets are loosing their power or the magnetron is screwing up, umm 30w oil is a little heavier then 10w-40. and its mono grade as well. not multi. have you tried the float, either its dented a little or its filling up and sinking or sticking. does it still use a points and condensor system under the flywheel?

Sorry I've been out of the loop lately - building a nice new house for my new Deere.

There are no points or condensor on this engine. When I look at the magnetron from the flywheel POV, there are some separations between the sandwiched layers of the pickup. I'm guessing that it is time for a new one.

No sign of any leakage in the float - I pulled the bowl off and the float is EMPTY. I put it in a coffee can with an inch or so of gas and weighted it down - it was still empty and floated after a few minutes.

I verified that the kill switch is working properly and that the ground is nice and clean. I'm thinking the magnatron unit is the issue, now.

yeah could be, though tec's are picky, one little degree off and they won't run or run right. thats why i stick with b&s.