Briggs and Stratton stalls after new carb kit


  #1  
Old 01-11-05, 03:13 PM
Mike H
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Briggs and Stratton stalls after new carb kit

I have an 8 h.p. Briggs and Stratton which runs a Coleman Powermate generator. Recently the carb started leaking gas. I installed a new carb kit and reinstalled it. I adjusted the idle mixture and needle valves according to owner's manual. I opened the gas valve from the tank and no leaking. The generator started. The generator ran but the RPMs didn't want to level out. I adjusted the needle valve and it ran better. I applied a load to the generator and it ran even smoother under the load. I adjusted the throttle for proper voltage output. During this entire process, the engine stopped several times as if it were out of gas. I would restart with little effort, usually a couple of pulls on the cord. I discovered that as the engine is dying, I can keep it running a while by closing the choke all the way. It runs smoothly, but only at half speed. Eventually it dies. It will restart again. Although I didn't time it, it runs about 3-4 minutes. Model# 190412 Type# 3098-01 Code# 89061310.
 
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Old 01-12-05, 12:15 AM
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Hello Mike!

Check fuel flow from the tank to the carb. Maybe the fuel line is collapsing internally and blocking fuel flow. Could also be a bad/clogged vent in the gas cap, allowing the tank to vapor-lock. Try loosening the cap a bit. Make sure the fuel cut-off valve is allowing fuel to flow freely.
 
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Old 01-12-05, 09:08 AM
Azis
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Possibly a low oil pressure switch also. I have had some that will act like that. Depending on how its wired, you may be able to unplug it to check. Look for a wire and terminal near the oil fill or drain.
 
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Old 01-12-05, 01:19 PM
Mike H
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Problem Solved-Thanks Cheese

As suggested, I changed the filter and fuel lines. The fuel cap was venting fine. While I was doing that, I pulled the carburetor and and did some minor adjustments to the float, it wasn't sitting quite parallel in the closed position. I put it all back together and it started on the first pull, more importantly, it stayed running until I shut it down. It's hard to say which fix corrected the problem, but the filter was a good idea since it was the original. This particular model doesn't have a low oil pressure sensor and shut off.
 
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Old 01-13-05, 12:35 AM
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Glad you got it fixed!
 
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Old 11-04-07, 12:45 PM
R
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Vapor Lock!

Son of a gun. My mower was also stalling after 10-15mins and then wouldn't start except w/the choke fully engaged. I replaced the fuel and air filters (they both needed it anyway) and still the same symptoms. I did notice that after letting it sit for 10minutes it would start up again but wouldn't run more than another 15 minutes. I watched the fuel filter and there was almost nothing going through. On the advice I found here, I check the gas cap...it was very tight. I loosened it snug but not tight and damn if the mower didn't start right up - no choke and it ran as long as I needed it to. Vapor lock - go figure!

Thanks - you saved me a carb rebuild!
 
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Old 11-05-07, 02:13 AM
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Technically, that is not vapor-lock, that is plain old fuel starvation. It sounds like you need to replace your fuel cap due to a plugged venting system. Vapor lock is when the fuel cooks from overheating and goes from a liquid state to a gaseous state.
 
 

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