JD 300 engine rebuild.. still no fuel draw

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Mista Mota
Posts: 12
Joined: Thu Jun 08, 2017 2:21 am
Real Name: Jeff
Location: Saskatoon

JD 300 engine rebuild.. still no fuel draw

Post by Mista Mota »

Hello

I have a 74 JD300, I replaced all the gaskets and seals on the engine, and i replaced the gaskets of the carb. but i still cannot get any fuel draw into the engine.. i tried blowing air into the fuel tank to "pressurize it" but i hear an air leak coming from the check valve. would that be enough of an issues to cause no fuel flow to the engine ?

and where would i find another one of these check valves as i cannot seem to find any at any of my local store or online...

thanks in advance
jeff
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jep_800
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Joined: Wed Dec 31, 2014 1:33 pm
Real Name: Jason
Location: Grand Forks, ND

Re: JD 300 engine rebuild.. still no fuel draw

Post by jep_800 »

Jeff,

Newbreed Parts has them: https://www.newbreedparts.com/newbreed/ ... m.html?p=3

Yes, I would replace that check valve, and then put in new pickup, return lines in your tank, and fuel lines to your carb. Be certain that you have the correct line connected to the fuel fitting on your carb. Might as well put in a new fuel filter while your at it. The center fitting is the fuel line, the one next to the edge is the return line.

JP
1975 John Deere 800
1975 JDX8 (VC Finisher 2019)
1976 440 Cyclone (VC Finisher 2022)
1974 El Tigre 440 (Sold)
1996 Arcitc Cat 440Z
Curlymurt
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Joined: Thu Oct 05, 2017 8:29 am
Real Name: Adam
Location: Indiana

Re: JD 300 engine rebuild.. still no fuel draw

Post by Curlymurt »

I needed to replace my needle and adjust it. The lever for the needle was way off from the old needle to the new.

I was also left scratching my head because the line from the left side of the carb to the engine block had a tear. Once I replaced that, it had enough suction to draw the fuel through the lines.
1972 Deere 400
Matt
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Location: Coopersburg, PA
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Re: JD 300 engine rebuild.. still no fuel draw

Post by Matt »

Curlymurt wrote: I was also left scratching my head because the line from the left side of the carb to the engine block had a tear. Once I replaced that, it had enough suction to draw the fuel through the lines.
That's the impulse line. The positive/negative crankcase pressure from that is what pumps the fuel in the carb.
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