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Small (Mower) Engine Question

Scotts 42" deck riding mower. Has the Tecumseh Briggs-Stratton 15 hp motor. Anyone know what the plug gap is supposed to be? I have scoured my owners manual front to back multiple times, and it says nothing about plug gap.

cannot go wrong with 35 thousands

All Briggs and Stratton are 30 thou.

You might find this reference handy :

They are all 30 thousanths, but Tecumseh is one company and Briggs is another. Which one is it? Thats like saying you have a Ford Chevrolet.

Use a matchbook cover until you find the exact gap. Always worked for me. Rocketman

Sorry its briggs. had tecumseh on my other mower.

It’s usaully printed on a small sticker somewhere on the engine or underneath the tractor hood-look around, you’ll find it.

35 thousands is probably a very safe bet.

But which engine is it…Tecumseh or Briggs-Stratton???

WARNING, absurd vector to new topic follows: A few years ago I decided to try synthetic oil
in my walk-behind lawn mower and like the results. The start pull rope seems to pull easier
and even with a slow, wimpy pull, the mower always starts first time. It seems to run smoother as well, but it might all be the power of suggestion or maybe the fumes have me halucinating.

I warned you.

I was using synthetic oil in ALL my power equipment like mowers and snowblowers LONG BEFORE I used it in cars. Typically I only changed the oil at the start of each season. I don’t think any will argue that synthetic is NOT superior to regular dyno oil. The main objection is the cost. But how much are you wasting with a lawnmower per year…$3…TOPS. Financially it makes sense to me.

I’m not happy with your post about synthetic oil in lawnmower engines. I’ve had the same mower since 1987. It took me 15 seasons to get it to the point where it wouldn’t start when it was hot. I would let the mower cool off while I cooled off with a beer. The mower also was useful as a mosquito fogger. Unfortunately, for my birthday a couple of years back, my wife took the mower to a shop and had a short block installed, and the mower starts fine when hot. Now you come along with a post about how synthetic oil will make the engine last longer. My wife saw the post and bought me 2 quarts of Mobil 1 synthetic oil for my birthday. Now I’ll never get this engine worn down to the point where I can have some enjoyment while I’m mowing.

I do have a generator and the manual recommends using synthetic oil for maximum engine life. I do make certain to use synthetic oil in the generator. I need something to reliably keep the refrigerator and hence my beer cold during a power outage.

Actually, your suggestion about using sythetic o8il in power equipment is a good one. Air cooled engines need all the help they can get in the lubrication department.