Lawn mower ran out of gas and wont start

16.5hp ran out of fuel yesterday on a mowing job, put in fuel but won't start. ether/petrol down the throat and it starts for 2-3 seconds. Its pumping fuel to the carby. I swapped another carby onto it today but it is exactly the same. Pulling my hair out, need it for work - please help!!!

Joined: Jan 2009

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Pushrod Honda preferrer

Using the last of the fuel sometimes results in water or dirt that was in the tank finding its way down the fuel pipe. Most times it gets to the in-line fuel filter and blocks it.

I suggest you disconnect the fuel line at the carburetor input connection, turn on the fuel, and see if you get a full flow out of the pipe. If you don't, try the same test with the filter removed (temporary bypass fuel line, or just disconnect the line upstream of the filter and repeat the flow test).

Do not replace a red (gravity feed) filter with a black (fuel pump feed) type or you won't get any fuel into the carburetor.

Joined: Jan 2009

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Pushrod Honda preferrer

If the engine had to be cranking to get a fuel flow it must have a fuel pump. Please post the Model, Type and Code so we can all get on the same page.

A silly question: are you sure the substitute carburetor was OK? It hadn't been out of service, resulting in it being gunked up somewhere?

Because it will run if you prime it directly into the cylinder, the problem isn't ignition or compression - it is fuel. Do you have a massive vacuum leak somewhere - e.g. carburetor insulator or gaskets incorrectly assembled? Vacuum tapping left open?

It sounds as if we need a bunch of pictures of the engine in the mower, and try to do this from first principles the way we normally do here. I know this doesn't meet your needs in this case because of the work situation.

Joined: Sep 2006

Posts: 154

Apprentice level 2

*FIXED*

a dodgy connector on the lead going to the shut-off solenoid...strange coincidence with the empty tank

those nikko carbs are nice and easy to work with as far as removal/replacement, seem to recall the walbro on the earlier L series being more finicky (this is the current 16.5hp briggs used on Cox mowers, nice when its running...a "f**king briggs!!" when its not lol)

Last edited by Redeye; 06/03/14 12:06 AM.

Joined: Jan 2009

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Pushrod Honda preferrer

Odd that you still didn't get it to make contact when you fitted a different carburetor, Redeye. I was wondering if it had an anti-dieseling solenoid, but there was no way you would have bad solenoids on two carburetors simultaneously, and a bad connector wasn't going to fail to make contact twice running. To me, there is no substitute for some decent pictures, so we see the solenoid, and naturally focus on it because they give so much trouble.

Joined: Jan 2009

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Pushrod Honda preferrer

That makes it more difficult, Redeye, I agree. It is the kind of thing people might or might not find, depending on how much they tend to focus on electrical issues. Above all though, there is the the unfortunate coincidence that the problem occurred at the same time as running out of fuel, which traditionally causes some specific knock-on problems that have nothing to do with solenoids. Maybe some of us would routinely substitute a bolt for the solenoid whenever a no-fuel problem crops up, and maybe we wouldn't. I think probably, those who have been through this particular problem might be tempted to put the bolt in and leave it, until such time as they were annoyed by the dieseling when they shut down the engine.

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