Small engine repair

December 16, 2007 11:49 AM

Trying to dig ourselves out here in New England... snowblower problems... Anyone know how to find out what the sparkplug gap should be for a snowblower?? Can't seem to figure out how to find out on the web.
posted by beccaj to home & garden (6 comments total)

Probably the same as for a lawnmower.
posted by Steven C. Den Beste at 11:57 AM on December 16, 2007

added difficulty: engine not the one orginally in the snow blower.. all I know is its a 7 horsepower tecumseh.
posted by beccaj at 11:58 AM on December 16, 2007

This site, if I'm reading it correctly, says that the spark plug gap for your Tecumseh should be .030 (.762mm). Scroll down almost to the bottom for the relevant section.
posted by amyms at 12:28 PM on December 16, 2007

.030 is a safe place to set it. it's probably set like that out of the package, but it's a good idea to check.

chances are it doesn't run cause the carb is all crudded up with varnish from last year's gas. the float bowl comes off easily on a tecumseh, usually, and you can clean it out and spray the dangly bits of the carb with some carb cleaner.

beats shoveling!
posted by KenManiac at 3:06 PM on December 16, 2007

The old rule of thumb for most motors was to use a paper matchbook cover to set the points gap (0.16 inch) and a folded matchbook cover to set the spark gap (0.35 inch). This was usually good enough to get an engine running until you could use a real gauge or dwell meter. Most spark plugs are 0.30 to 0.35. Unless they have been dropped, most spark plugs these days come out of the box gapped pretty accurately.
posted by JackFlash at 6:33 PM on December 16, 2007

Agree on all the above, about 0.030" is common. You should be able to crank the engine over with the plug out and observe the spark; if it's not there then you have other problems like a busted magneto, corroded points (give 'em a good wipe with 800-grit) or a dried out ignition capacitor.

If you can see a spark, then adjusting the gap won't have much effect unless it's wildly wrong, which will usually cause problems under load, but the engine should still start.

If it's not starting and you have spark, is fuel coming in? Cranking without the plug in should result in puffs of white petrol vapour coming out of the spark plug port.
posted by polyglot at 9:55 PM on December 16, 2007