Briggs and Stratton Vanguard 18 hp running lean

shagster

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Hello, I am working on a Briggs and Stratton 18 HP Vanguard engine in a 10k generator. Model number 356445 0208-G1 10110311. Engine runs lean, it surges slightly and the spark plugs are practically white. If I close the choke slightly it clears up nicely. The generator is ten years old with little use. So far I have drained and flushed the fuel tank and line, it wasn't terrible. I then removed the top half of the carburetor and cleaned the pilot jet, main jet which is located in the side, and removed the float and needle to clean the seat. I blew out all the passages and cleaned the float bowl. Overall the carburetor wasn't that dirty or corroded. Reassembled and filled tank with non-ethanol 92 octane fuel. Still runs on the lean side and again closing the choke slight makes it run so much better. I have drilled out jets in the past but was wondering if anyone has any first hand experience with this concern with this engine? It does a have an idle adjustment screw with a plastic lock on it that I haven't touched yet. So any input would be greatly appreciated. Thankyou!
 

bertsmobile1

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get a trigger spray bottle and fill it with WD 40 or similar.
remove the blower housing and saturate the manifold and carb with it slowly from the engine back.
If there is an air leak it will suck in the WD 40 which will make the engine miss a little & blow white smoke
 

slomo

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Dirty carb. This is a standby product sitting for untold days/months/years. You need to strip the carb down entirely. Might take 4 cleanings to get her alive proper. Strip it down and put it in the wife's dishwasher on HOT pot scrubber mode with a quart of pure ammonia. Spray it all out again with carb cleaner. Don't spray any plastic or rubber parts with carb cleaner. Blow all passages out with an air compressor/blow gun nozzle.

You should never have to drill out any jets. Most all OPE runs on the rich side. I would love to lean out a bunch of mine a bit. Plugs would run cleaner.

slomo
 

slomo

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Your "wasn't terrible" comment to me meant it was filthy. Any dirt or varnish in there, other than fresh fuel is filth. Need to remove the pilot jet and clean it all out.

slomo
 

100 td

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Get a set of oxy/acet welding tip cleaners, and run them through the main jet particularly, a tiny layer of varnish builds on the inside of the jets reducing its diameter and reduces fuel flow, you can see through the jets and they look clear but are slightly diminished in diameter due to build up. Have had the problem on my own equipment and other folks. Worth a check, works for me. You aren't making/drilling the jets bigger, just scraping off the varnish to bring them to their correct size. Something like these
 

Born2Mow

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Old gas will put a varnish coating on parts of the carb interior due to the ethanol. Non-ethanol is a fix too late. Obviously, this "coating" includes the interior of the jets, which get smaller due to the varnish. The smaller jetting orifii then lean out the engine.

The best thing is simply get new jets... if they screw out. The brass is machined so finely that you never want to use abrasives like torch tip cleaners. Maybe the hardest thing would be round wooden tooth picks (the long, fat fancy ones for h'orderves) dipped in carb cleaner. If the generator is seeing a lot of run time, then you could also dope the fuel with StarTron, which is a cleaner and stabilizer. But that might take take too long.

If you decide to open the carb back up, then pay attention to the smaller jets. They are the ones that clog first and are effected the most by the varnish.

PS. If you do use the high class h'orderves sticks, then decorum dictates you should hold your "pinky" in the air. :ROFLMAO:
 
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100 td

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A tip cleaner is a fixed size, designed to clean out a cylindrical component, a tooth pic doesn't get in and clean the walls of the cylinder, it just chamfers the opening as you try to force the bigger sized log into the small hole. If you have time and money, order/buy new jets, or a whole new carby, if not get some tip cleaners. Each to their own though. YMMV
 

ILENGINE

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A tip cleaner is a fixed size, designed to clean out a cylindrical component, a tooth pic doesn't get in and clean the walls of the cylinder, it just chamfers the opening as you try to force the bigger sized log into the small hole. If you have time and money, order/buy new jets, or a whole new carby, if not get some tip cleaners. Each to their own though. YMMV
Those are the file type cleaners which are not recommended because the can enlarged the jet. Non file type are recommended. And Briggs recommends the toothpick
 
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