Briggs 18hp vangaurd trouble.


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Old 04-15-14, 02:56 PM
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Briggs 18hp vangaurd trouble.

Hello everyone. I'm hoping someone can help me with my problem. I have a briggs vangaurd that backfires under load. I've checked almost everything including valve clearance,filters, gas tank for vapor lock coils plus testing diode wire, compression test , leak down test ( normal). Number 2 cylinder plug looks sooty and had a little oil on it. Number one is clean as a whistle. Almost to clean. I went through the carb and found no dirt. I did clean it out. I'm thinking I have a burnt valve but I don't know what side. Also the problem occurs more and gets worse went hot and more run time. Thanks for any help.
 
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Old 04-15-14, 06:48 PM
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Is it an occasional backfire amidst otherwise perfect running? Does the engine surge at idle? Does applying partial choke help or stop it from backfiring? Is it a very loud bang out the exhaust, or a little pop, or is it through the carburetor instead of the exhaust? Is the clean plug white looking at the electrode?
 
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Old 04-16-14, 09:28 AM
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Once it starts it's fit it runs pretty rough. Half choke will help it. Enough to get by. I did notice the number two cylinder spark plug boot was split and arcing to the head bolt, like a good half inch arc. So far it seems alright. Won't know for sure until it gets some run time. But that fix certainly didn't hurt anything. The backfires did not seem to be coming from the exhaust but it's still possible because of the way the exhaust is on this mower. It has a long exhaust system. Thank you for your reply!
 
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Old 04-16-14, 09:45 AM
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Sounds like a carburetor issue still. The arcing spark problem is fixed?
 
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Old 04-16-14, 04:24 PM
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Yes I put a new boot on to fix the arcing problem. It deffinatley ran better. The text will be when it runs for a while. Everything seemed clear and clean throughout the carb. I guess it could still be a problem though. I have found that out with some small two strokes.
 
 

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