Briggs Backfiring! New Carb, and Cam done. Now what?
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if you're thinking you got the wrong carb from the thread i linked, that engine is bit different from yours. However they do appear to use the same 791230 carb.
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suparoood
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According to the box, its the right number. I'll check the intake leak. I was going to tonight, but no carb clean.
Side question about the carb. The new one came with gaskets, while the original has the Oring. I looked at it for a while, but decided to reuse the old Oring. Is the gasket for a different style intake that always used gaskets? Is it an up-change? If I did find a leak, can I use the gaskets in place of the Oring? Should I use BOTH? I know best answer is just get some proper O rings. But just curious why the included none in box, but did give gaskets.
My thought process was use an oring if it's an oring, and it didn't come with. I didn't like how thick the gasket was, for the reason that it would move the carb/intake the tiniest amount further out, and possibly introduce new issues, with jetting etc. which scared me off due to knowing the dual jet sizes for such tiny differences. I've decided I'm going to try to peek at the valve guide with the head on, by removing valve cover and possibly the springs (filling combustion chamber with rope to prevent valves from falling - good trick btw for lots of things, like removing crank bolts and preventing crank from spinning. Can also use air pressure from leak down tester, but I don't like noise, haha)
Anyways, plan for tomorrow is to test for intake leak, and try to be tricky and see if it looks like valve guide has moved at all from the top. Also will try to verify if my spark tester is accurate on some other engines at work.
Side question about the carb. The new one came with gaskets, while the original has the Oring. I looked at it for a while, but decided to reuse the old Oring. Is the gasket for a different style intake that always used gaskets? Is it an up-change? If I did find a leak, can I use the gaskets in place of the Oring? Should I use BOTH? I know best answer is just get some proper O rings. But just curious why the included none in box, but did give gaskets.
My thought process was use an oring if it's an oring, and it didn't come with. I didn't like how thick the gasket was, for the reason that it would move the carb/intake the tiniest amount further out, and possibly introduce new issues, with jetting etc. which scared me off due to knowing the dual jet sizes for such tiny differences. I've decided I'm going to try to peek at the valve guide with the head on, by removing valve cover and possibly the springs (filling combustion chamber with rope to prevent valves from falling - good trick btw for lots of things, like removing crank bolts and preventing crank from spinning. Can also use air pressure from leak down tester, but I don't like noise, haha)
Anyways, plan for tomorrow is to test for intake leak, and try to be tricky and see if it looks like valve guide has moved at all from the top. Also will try to verify if my spark tester is accurate on some other engines at work.
suparoood
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For those following this, I sprayed carb clean around the intake, no change. I pulled the valve covers to inspect if the valve guides had moved. They looked to be in the exact right spot, and the same on both, roughly a 1/4" up. The 14YC spark plugs helped as it ran smooth for 10+ minutes, but is starting to carbon up again, and I could faintly here the popping starting again. I told him there is either something odd, like a crack in the head, a slightly bent valve, or slightly worn guide or something of that nature, or leaky head gasket maybe. Or else something acting up with the ignition system, like lazy coils. But we are both completely done with this engine for right now. I have no other ideas without taking the heads off, which costs 70-80$ just for gaskets, and may not find the problem. So we will wait until spring unless anyone else has any ideas.
Side note, it doesn't backfire until the plugs start carboning up again from what I can tell. And new plugs always seem to run fine for 10-15 minutes. Once again leading me to a carb problem. Is there any definitive way to say a carb is good or bad? Like I can't just take it back and say, I think this part that I've now used is bad, give me another one.
Side note, it doesn't backfire until the plugs start carboning up again from what I can tell. And new plugs always seem to run fine for 10-15 minutes. Once again leading me to a carb problem. Is there any definitive way to say a carb is good or bad? Like I can't just take it back and say, I think this part that I've now used is bad, give me another one.
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you can get a Stens Link: Stens 465-512 head gasket for $15 through Amazon.
suparoood
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So I read through this entire thread https://www.lawnmowerforum.com/threads/24hp-v-twin-b-s-fault-driving-me-crazy.50838/page-19 . I'm sure a few of you remember it from last year. It sounds like the issue Neo7 had was a bad intake, that he updated to an aluminum one, as well as a faulty knock off carb that hid the problem(as well as spraying carb clean not showing the problem) I have a carb directly from JD dealer, and was in a Briggs box. So I suspect the carb is fine. I do however suspect an issue with the intake. Anyone know the part number of the upgraded aluminum intake? It seems the plastic part number is 595606. I'm very tempted to try one, and if it doesn't work, just take it back as it will stay in new condition, and I have the gaskets already that came with the carb, so no harm no foul.