Tecumseh 8.5 HP Snow King Engine LH318SA Air Bleed question

NickD

wrench
Joined
Aug 28, 2007
Messages
5,041
Points
48
Son purchased a new Troy-Built snow thrower with this engine, since new, engine surges like crazy, spark plug is black, won't idle, but does start on the first or second pull.

Took a look at it last Friday, really runs rough, no mixture adjustments on the carburetor, period, just has an idle speed adjustment, and what is called an air bleed screw right above the fuel bowl with a plastic cap on it. It was seated, I backed it off about a half a turn, and the engine came to life, backfiring quit, and ran much smoother. I talked to a Tecumseh tech, said that on some engines, this air bleed has to be backed off to get it to run smooth, but have to put Locktite on it or it will vibrate loose, has no spring on it.

Also talked to the dealer the one I purchased my blower from, not my son's and he gave a different story, says the engines come with gas in it that gels blocking the low speed circuit, carburetor has to be removed, and cleaned. And that air bleed has to be seated. Oh by the way, Tecumseh will not repair this under warranty, claims it's your gas and not theirs. This is ironic as their manual tells you to drain the tank for storage, but dealer tells me they all come with about a half a tank full, that sounds crazy, shipping a blower with gas in it.

So two different stories on the same problem. Plan on removing that carb and cleaning it and see what's happening. The Troy-Built I just purchased has a Chinese copy of the Honda engine, starts with a half a pull with no strain, powerful, and extremely quiet, quite an improvement over that Tecumseh. Neighbor has last years Tecumseh, can hear that thing backfiring in the house, he is blowing right now, maybe I can fix his too, to get some peace and quiet.

Always had high regards for Tecumseh, but beginning to learn why MTD dropped them, their technician on the phone was quite rude. Anyone else having this same kind of problem?
 

NickD

wrench
Joined
Aug 28, 2007
Messages
5,041
Points
48
fixed, finally got over there, removed the carburetor, every simple, took it apart and blew it out with choke and carb cleaner, about the cleanest carburetor I ever took apart. Main jets and the holes in the idle restrictor valve looked very clean, but blew them out, anyway. Really the only thing I noticed was the carb to intake manifold bolts were loose, they aren't loose now.

If you take one of these apart, get a magic marker, the governor lever and the throttle lever both have a lot of the same size holes in them, must be for multiple applications, circle the holes the linkage is in. Pulled the starter rope, started the first pull and ran smooth, well as smooth as you can expect from an L head Tecumseh, and that was with the idle restrictor seated the way it's suppose to be.
 
Top