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View Full Version : Why does Briggs & Stratton motor push gas out cap?


Bobcat1
07-20-2011, 07:05 PM
I am trying to get my bobcat with a B&S 5hp engine running. Right now it will run for a few minutes with the choke on but as it runs, it pushes gas out from around the gas cap and the tank is only 1/4 tank full.

Anyone know why that might be?

I figure there is pressure in the tank but I have never seen this before.

Thanks!

monoshock
07-20-2011, 08:18 PM
Try running it with the cap loose and see it that helps. Maybe lay a rag over it to catch the gas.

wandfsmall
07-20-2011, 10:05 PM
I am trying to get my bobcat with a B&S 5hp engine running. Right now it will run for a few minutes with the choke on but as it runs, it pushes gas out from around the gas cap and the tank is only 1/4 tank full.

Anyone know why that might be?

I figure there is pressure in the tank but I have never seen this before.

Thanks!

I agree with monoshock that it could be a gas cap but the choke thing leads to the carb as the problem...... a gas cap usually will allow it to run fine for a short time then die out. plus it is pushing it out of the gas cap not trying to suck air in. I would say look at the carb first...

Bobcat1
07-20-2011, 11:06 PM
Thank you. What would make the carb want to blow gas in reverse instead of sucking it in?

wandfsmall
07-21-2011, 08:31 AM
Thank you. What would make the carb want to blow gas in reverse instead of sucking it in?

now that I can not help you with as I would have to see the carb.

Bobcat1
07-21-2011, 03:42 PM
Here is a picture of the carb with the throttle full open and the choke closed.

The next picture is the throttle halfway open and the choke open.

Does this help?

Right now it seems like it will only run full throttle with the choke on and when I try to slow it down, it dies.

Steve
07-22-2011, 05:47 PM
When the carb is closed, it should suck up and force more fuel into the engine. So I am not sure why it would be forcing pressure out into the gas tank.

wandfsmall
07-22-2011, 11:16 PM
after looking at all of your posts on this engine have you looked at replacing the engine? after you buy all of the parts I have a feeling your looking at you could get a new engine. The frame is worth it but are you sinking money into an engine that could be older then a lot of members here.