Spark plug gap?

[never_retreat]

Anyone know about what the gap should be for a 10hp briggs and scrap iron engine?
My snow blower was not running good, actually it will only run with the choke on. I removed the plug to clean it and dropped it and well "lost" the gap.

[Boomhauer]

Need moar engine info.

Heres a start...

http://www.briggsandstratton.com/support/frequently-asked-questions/Identifying%20the%20correct%20spark%20plug%20and%20gap/

[cassandra and sara's daddy]

a dime

[Tallpine]

Would depend on whether it is points/condensor or electronic ignition.

Seems like for points* was about .030 and for electronic about .050.


* NOT the points themselves, plug on a points system

[Fly320s]

Check the air filter, too.

[dogmush]

.035-.040 will get just about any gas engine running well enough to diagnose the other issues. On a B+S it'll do it fine unless you're running a jr dragster.

[never_retreat]

I set it to .030 earlier before this post. Sounds like it should do the trick. I don't have the manual for it. Its on a 15 year old craftsman snowblower I inherited.

[Hawkmoon]

.035-.040 will get just about any gas engine running well enough to diagnose the other issues. On a B+S it'll do it fine unless you're running a jr dragster.

^^^ This.

I use .035 for everything from lawn mowers and chain saws to my race engines.

[Gewehr98]

I've been using 0.035" since my dad taught me in the mid-1970s, on damned near everything.

Oh, and I'll take a Briggs & Stratton any day over a Tecumseh, even if I have to rebuild the former.  I consider the latter disposable. 

[Boomhauer]

I've been using 0.035" since my dad taught me in the mid-1970s, on damned near everything.

Oh, and I'll take a Briggs & Stratton any day over a Tecumseh, even if I have to rebuild the former.  I consider the latter disposable. 

Damn right. I can usually get an B&S running. Tecumsehs are tools of the devil.

[French G.]

I'll 4th the .035 and forget it, it is just not that important. It will run a chainsaw, it will run a 800hp alcohol motor. Verify your spark then go fix the problem. Only run with the choke on, so you have spark. Also means you have not enough fuel to match your air. So, blow through the carb with good cleaner, clean the gas tank, hope that fixes it before you have to disassemble the carb and clean out the fuel pick-ups. Can I bet the safe line on old ethanol containing gas?

[never_retreat]

I'll 4th the .035 and forget it, it is just not that important. It will run a chainsaw, it will run a 800hp alcohol motor. Verify your spark then go fix the problem. Only run with the choke on, so you have spark. Also means you have not enough fuel to match your air. So, blow through the carb with good cleaner, clean the gas tank, hope that fixes it before you have to disassemble the carb and clean out the fuel pick-ups. Can I bet the safe line on old ethanol containing gas?

It has staybil marine in the gas. so 

[Cliffh]

I've an old tiller with a B&S motor on it, when it last ran it would only run with the choke full on.  That was the second time this symptom appeared.

The cause was an air leak around the top of the butterfly shaft.  Instead of rebuilding the carb, I bought a new one for ~$35.  Ran fine until it was over-wintered a second time, pulled the same crap again after running for a few hours.  Didn't bother to fix it the second time, needed a larger tiller anyway.

[French G.]

It has staybil marine in the gas. so 

I lose again. Still need to clean the carb and make sure fuel is getting through.

[Tallpine]

If it's solid state ignition, it will run better at around 0.050"

Except I usually just eyeball it and it runs fine  


PS: sometimes a spark plug will go bad but it looks just fine.  I've had that a couple times on chainsaws: it suddenly won't run or runs like crap and a brand new plug fixes it. 

[never_retreat]

Well got done snow blowing 6" of crap. Thing is still running like shat, tried adjusting air and gas and no dice. Still wants some choke to stay running. I'll have to drop it off to the mower shop. God I hate small engines.

[Tallpine]

Well got done snow blowing 6" of crap. Thing is still running like shat, tried adjusting air and gas and no dice. Still wants some choke to stay running. I'll have to drop it off to the mower shop. God I hate small engines.

You might try a brand new spark plug first 

Although it is probably an air leak somewhere.

[geronimotwo]

Well got done snow blowing 6" of crap. Thing is still running like shat, tried adjusting air and gas and no dice. Still wants some choke to stay running. I'll have to drop it off to the mower shop. God I hate small engines.

i have a similar craftsman.  every winter it starts off like that, needing the choke to run.  i find if i turn the carb mixture screw all the way in, and then back it out the same number of turns, it will let me adjust the mixture better and will run well for the rest of the year.  to finalize the adjustment, let the engine warm up and (at full throttle) keep opening the mixture screw until it runs without the choke.   mine runs best under load if it is a 1/4 turn past where that setting takes me.