Need help w/ my damn mower.
03-29-2007, 09:01 PM
#1
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Need help w/ my damn mower.
It's a Murray w/ a Briggs and Stratton motor.. Damn thing only stays running w/ the choke on.. take choke off.. it dies. I've put all new fuel filters on it.. wondering about bad gas.. but not sure. any ideas? I've checked all fuel lines.. ran through the whole thing.. blew out carb, all of that
03-29-2007, 09:23 PM
#3
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Re: Need help w/ my damn mower.
You need to clean the fuel pump on the carb. How many bolts are on the fuel pump? If it's a 3 bolt fuel pump they don't flow as much. The 4 bolt ones suck much more fuel. The problem that you're experiencing is not enough fuel, I can guarantee it. So you can do a few things... clean the fuel pump, find a new 3 bolt which is easy because every old briggs twin has one, or find a 4 bolt fuel pump which is on the newer briggs non-ohv. Your's is an opposed flathead, right? It's not bad gas and it's not fuel the fuel filter, it's that the pump isn't sucking enough gas. Another thing you can do is pull the whole pump off the front of the carb and run a gravity feed of gas, but that would require fabricating a bracket to hold a fuel tank above the engine.
03-29-2007, 09:26 PM
#4
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Re: Need help w/ my damn mower.
have you tried here http://forum.doityourself.com/showthread.php?t=265753
03-29-2007, 09:29 PM
#5
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Re: Need help w/ my damn mower.
Oh yeah another thing you can do is pressurize the fuel tank with 2psi, that will push the gas through the lines. The fuel pumps on the carbs of briggs opposed twins are operated by vacuum pulses and they only pull 2-3psi, but the diaphragms in them are weak as ----. Spray carb cleaner directly into the jets as well with the little red hose thingy.
03-29-2007, 10:51 PM
#6
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Re: Need help w/ my damn mower.
Originally Posted by TorganFM
You need to clean the fuel pump on the carb. How many bolts are on the fuel pump? If it's a 3 bolt fuel pump they don't flow as much. The 4 bolt ones suck much more fuel. The problem that you're experiencing is not enough fuel, I can guarantee it. So you can do a few things... clean the fuel pump, find a new 3 bolt which is easy because every old briggs twin has one, or find a 4 bolt fuel pump which is on the newer briggs non-ohv. Your's is an opposed flathead, right? It's not bad gas and it's not fuel the fuel filter, it's that the pump isn't sucking enough gas. Another thing you can do is pull the whole pump off the front of the carb and run a gravity feed of gas, but that would require fabricating a bracket to hold a fuel tank above the engine.
03-29-2007, 11:33 PM
#7
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Re: Need help w/ my damn mower.
Well there's really no best way since the caps, at least on mine, had valves in them. I would try finding a different carb. My race mower was like that. If I had no choke it would sit but if I gave it full throttle it would sputter and have a super low rev limit. However, if I got it going then gradually opened the choke from closed to open as I was accelerating it would work fine. Your best option at this point is to find a new carb, they shouldn't be more than a few bucks on ebay. You could even try a bike carb and make a custom manifold. On my next race mower I'll be doing this along with running a solid rear axle.
03-30-2007, 12:03 AM
#8
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Re: Need help w/ my damn mower.
Originally Posted by TorganFM
Well there's really no best way since the caps, at least on mine, had valves in them. I would try finding a different carb. My race mower was like that. If I had no choke it would sit but if I gave it full throttle it would sputter and have a super low rev limit. However, if I got it going then gradually opened the choke from closed to open as I was accelerating it would work fine. Your best option at this point is to find a new carb, they shouldn't be more than a few bucks on ebay. You could even try a bike carb and make a custom manifold. On my next race mower I'll be doing this along with running a solid rear axle.
