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 Build carb riser for Kohler M18?

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Ranchrodder
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PostSubject: Build carb riser for Kohler M18?   Build carb riser for Kohler M18? Icon_minitimeThu Sep 14, 2017 12:09 am

I am currently running a vertical shaft Kohler M18 with a Molkt 26mm modified to fit. It is a gravity feed carb, but due to the height of the engine on the Murray frame, I lose fuel flow after I get around half tank.

Could I build a short riser (technically a dropper...lol) out of pipe that would drop the carb down below the tank level? Maybe two or three inches max, with as few bends as possible. It would have flanges on both ends.

Could this work, or would it cause issues?
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MightyRaze
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PostSubject: Re: Build carb riser for Kohler M18?   Build carb riser for Kohler M18? Icon_minitimeThu Sep 14, 2017 12:19 am

Is there a place on that engine to hook up a plus pump?

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Modified Tractors:
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Ranchrodder
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PostSubject: Re: Build carb riser for Kohler M18?   Build carb riser for Kohler M18? Icon_minitimeThu Sep 14, 2017 1:23 am

It has the factory cam driven fuel pump, but it pushes the needle valve off its seat. Is that the same thing as a plus pump?

I never had problems when I had the Briggs 18hp, it had the carb down low. Lol.
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CraftsmanQuad19
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PostSubject: Re: Build carb riser for Kohler M18?   Build carb riser for Kohler M18? Icon_minitimeThu Sep 14, 2017 9:27 am

I believe he meant *pulse pump, which is powered by the PCV valve. They don't make as much fuel pressure so shouldn't push the needle valve off the seat. I would do what @prancstaman suggested and just run a T fitting at the carb so you have a return. The carb will get plenty of fuel and it will act as a pressure release so the needle doesn't get pushed open
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MightyRaze
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PostSubject: Re: Build carb riser for Kohler M18?   Build carb riser for Kohler M18? Icon_minitimeThu Sep 14, 2017 9:27 am

That would be mechanical.  So you saying it is too strong for the carb?  That would be an interesting situation you have with that Molkt 26mm modified to fit.  You could try it.  The info above sounds good and easier.

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Kal-El 82 Murray GT
TheGreenMachine - "coming 2022"
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Ranchrodder
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PostSubject: Re: Build carb riser for Kohler M18?   Build carb riser for Kohler M18? Icon_minitimeThu Sep 14, 2017 11:20 am

Yes. It is at least as strong as a newer pulse pump like my 23hp Briggs v twin (on my mower that actually mows), if not stronger. It fills it up fine but then it overflows through the bowl drain and in front of the throttle slide. It starts running super rich when that happens. If I cut off the fuel it stops overflowing.

I will try that. And yea, it was never designed for a Molkt carb, but hey, a Murray frame was never designed to hold a 150lb Kohler M18 either. Lol
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Build carb riser for Kohler M18? Empty
PostSubject: Re: Build carb riser for Kohler M18?   Build carb riser for Kohler M18? Icon_minitime

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