GT 1142 carburetor

[Andy L 0]

I have a 1982 GT1142 which has run great for years. It has the stock 11hp B&S engine. Just recently I've had troubles with it running properly. In choke, the engine runs like normal but then knocks out after a minute or 2. It used to start to spudder in choke and I'd slide it to high and off we went. The local shop said it could be an ethanol related issue. I removed the carb, disassembled it, soaked and cleaned it and put it back on. I removed the gas tank, cleaned it and the small screen at the shut off and put that back together. I removed the fuel line and there's gas pumping out when it turns over. Their last resort recommendation is to purchase a new carburetor. Would you recommend a rebuild kit first or just go for the new carb, or is there something else I can check?

[Save Old Iron 1,571]

:scratchead:

Sounds like the carb is running very lean - maybe that's why choking it ( enriching the mixture) allows it to run better for a brief period.

Probably some buildup internally that was not removed by the first soaking in carb cleaner.

A rebuild kit seems like a reasonable 2nd step if additional soaking and cleaning of the internal passageways does not address the issue.

Also check the side to side play in the throttle shaft rod, If excessive, air may be sneaking in around the throttle shaft making the whole system run very lean.

[Andy L 0]

I did notice there was side to side play in the throttle shaft rod and when it was cranking, gas must have been leaking out around the throttle shaft because the top of the carb was wet. Would the rebuild kit address this issue?

[Save Old Iron 1,571]

A rebulid kit sounds reasonable - some briggs carbs have throttle shaft seals - o'ring like seals - very inexpensive but very important

the gas leak needs to be addressed immediately as it represents a fire hazard - look for a leaky float needle or damaged gaskets on the carb body. Grunge buildup in the carb could cause a lean run condition ( clogged passages) and cause fuel flooding ( needle valve not sealing correctly).

find the proper rebuild kit for your carb and have at it.

P.S. do you see any white mist coming from the carb throat while the engine is turned off after a short run ?? - usually indicates a stuck needle valve when the carb floods.

[Andy L 0]

Yes on the white mist. And I always got one back fire when I turned the engine off.

[Save Old Iron 1,571]

Andy,

sounds like you might have at least two issues here - overflowing fuel from a stuck needle float and probably partially clogged internal passages withjn the carb body.

both probably from dirt / residue in the carb body

take the carb apart - remove the needle valve from the float assembly and check for damage to the needle valve tip and any residue in the float seat area - bet there is something keeping the float needle valve from sealing off the fuel entry into the carb when the fuel bowl is full - uncontrolled fuel overflows into the carb and makes the fuel / air mixture rich - engine stalls and backfires from excess fuel being blown into the hot exhaust manifold and is ignited.

the mist is from the excess fuel vaporizing in the carb / manifold area

you might as well disassemble - re-clean and rebuild including the throttle plate shaft seals

good luck partner :scratchead:

[rick 255]

Be sure to check the top of the carburetor closely for warping....clean the gasket surfaces carefully, put the top on the body of the carburetor w/o a gasket. There should be very little to no gap where they come together. I bought a new carburetor for my C111, the sum of the parts to properly repair it was more than a new unit.

[Andy L 0]

I went to briggsandstratton.com with my engine number 252417 0664-01 and found the carburetor. They list an entire carb but unfortunately it comes up "no longer available." The odd thing is it looks like I could order every piece but I would like to know what a new one would cost. Where else could I look for an assembled carburetor? Appreciate all your input!

[rick 255]

I did a search, came up with part number 392587 for a complete carburetor.

Lists for 190.25 from Briggs, 167.95 from www.smallenginesuppliers.com., and 180.74 from Jacks. I think I paid around 160.00 for the one I bought.

[TT-(Moderator) 1,162]

The correct carburetor is #397486 and is - as previously stated - no longer available.

That doesn't mean that a newer or slightly different 10hp horizontal shaft Briggs carburetor can't be used, but it won't be a direct swap.

[rick 255]

On reading TT's post, I checked again....I stand corrected, from Briggs & Stratton Form MS-6928-10/97 the carburetor part number comes up as 397483, and is alive and well priced at $179.55 from the makers.....

The part number is found on the second carburetor page, top of center column of part numbers.

[Andy L 0]

So I went the route of purchasing a new carburetor from Briggs & Stratton, part #397483. Bolted right on and with a little prime, she fired up. It ran rough at first, I didn't touch any of the adjustment. I see 3 spring loaded screw. 1 at the base of the carb that goes in diagonally, 1 at the top of the carb just before the intake, and 1 on the throttle valve? thats kinda hunting (at hig speed). At low speed there's no skip and it idles great. I turned the one at the base of the carb clockwise 1/2 turn. It seems to have smoothed out and most of the hunting stopped. It sounds better, with only an occasional skip. So, am I done with the carb adjustments? What are the other adjustments for?

[Andy L 0]

Forgot to add one thing, even with the new carb, when I shut the engine down after running for more than a few minutes, I get one backfire ???