Breather tube, Intake V- Twin

kh0432 said:

The fuel pump (new) doesn't seem to be pumping enough gas. I'm also getting some backfire throughout the carburetor when starting. I'm going to check the valve clearance and flywheel key next.

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bertsmobile1 said:

Remote impulse fuel pumps very rarely give you any trouble.There was 4 in the parts box when I bought the business 6 years ago & I have only used one of them.
There is a small sintered brass filter that can get clogged which limits the pumping action as air can not escape fast enough.
Did you remove the pump ?
If so the intake is on the side nearest to the impulse line and the output is on the other side.
There is a check valve on the output on cheap ones and a check valve on both fuel lines on the expensive ones.
A mower will run for near 2 minutes on a float bowls worth of fuel which is 1 to 2 ounces so the pump does not have to shift a lot of fuel.

Remove the impulse line and hold some tissue near the end.
Start the engine and you should see the paper flutter.
I used to use the old tounge till some one here suggested the tissue, not as tasty but stops the nose getting burned.

When you reply to Gonzo with the make & model numbers, also post the symptoms you are having.
The internet is free ( well sort of ) so don't be shy.
There is no such thing as too much information.

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