Briggs engines stalling; bad carb?


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Old 08-26-16, 10:23 AM
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Briggs engines stalling; bad carb?

Got a head scratcher. 3 different Briggs engines(12 to 13hp) stall after running, while cutting, for about an hour to hour and a half. One smells of gas after quitting, other puffs dark (grayish) smoke, sputters, then either comes back to life
for a while or dies and has to sit for a while then starts up. Gone thru the carbs on all 3 in a sonic bath (completely disassembled) then I spray carb cleaner thru them to make sure every thing is flowing. Have checked flywheel pin and valve lash and made sure choke is working properly. Next step, in my mind, is to replace carb. For some reason I'm thinking it could be something else and don't want to waste money. I have also checked compression and all are right at about 100.Any help is greatly appreciated!!! P.S they are all riders.
 
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Old 08-26-16, 10:27 AM
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I suppose the fuel tanks are well vented and not creating a vacuum over that hour of usage ?
 
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Old 08-26-16, 11:16 AM
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I replaced the cap on one of them, guess that's a cheap test. Thanks
 
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Old 08-26-16, 12:12 PM
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The assumption that all three have the same problem may lead you down the wrong path, although it could be. I would take them one at a time.

When it dies, check for spark with a good grounded plug. You may have a weak coil that gives out when hot. Use that as the first check on all three. If you find you have a weak spark (yellow, no bright blue) disconnect the kill wire at the coil and try again. If it's still weak, replace the coil.

After you have checked out the coils go back to the carb. The 100 lbs of compression is fine.
 
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Old 08-26-16, 01:15 PM
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marbobj Thanks. I've had that thought in the back of my mind for a while now! I put my spark test on it and it fired. Coil reads 4.9k ohms. So I'm going to run it a while to heat it up and read it again. Thanks a bunch!
 
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Old 09-10-16, 09:21 AM
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Well I'm back on #2. It is definitely staving itself for fuel. I replaced the fuel line and filter. All seemed to go well, cut mine and my neighbors yards, then tried to start it the next day, it wouldn't start but I saw it was empty! Refilled after replacing the needle and seat. Started and it ran for a while but spit and sputtered then died. Had my meter ready and checked the coil hot,5.1k. This one is a 10hp Briggs with a Walbro carb. I can see through the filter that it doesn't stay full of fuel always. Did a pressure check on tank and it's vented well, doesn't have a vacuum. Cap is new. Gap on armature is correct and fly wheel key is in tact. Needle and seat hold pressure. Carb? Please help me!!!!!!
 
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Old 09-10-16, 09:41 AM
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Pull the fuel line off below the filter and let it drain the tank into something to see if the flow is good enough to keep the bowl full. Have a good one. Geo
 
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Old 09-10-16, 10:34 AM
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Just did that and flow was great. Put filter back on and did it again, flow was great.
 
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Old 09-10-16, 11:18 AM
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Please post the model type and code for this engine. xxxxxx-xxxx-xx
While it is running spray/dribble some carb/brake parts cleaner behind the carb and along the intake if the engine tempo changes you have an air leak causing the lean condition. Have a good one. Geo
 
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Old 09-10-16, 12:27 PM
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Briggs 214907 0272 E1. I did the carb spray and didn't hear a change, but it spit and spluttered and died again so I pulled the fuel line right away and it seamed to flow good. then I rerouted the fuel line under the air cleaner to give the fuel line more of a long slope. Fired it up and it ran smother than ever for a while. Started to spit and sputter again so I shook the fuel line and it smoothed out. Hardly any sputter and I used a squirt bottle with gas at the front and back of carb with no rev up at all.
 
 

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