YM336D Fuel pump problems

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Kavaman
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YM336D Fuel pump problems

Postby Kavaman » Wed Apr 24, 2019 2:35 pm

Hi everyone, I have a Yanmar YM336D and it looks like my fuel pump is bad. I checked the price for a new one and it was over $500.
Is it possible for me to use a universal electric fuel pump instead?
Also if I have to change the old pump because a electric pump will not work, how do I get the mechanical pump out? Thanks.

Kavaman

Aaron
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Re: YM336D Fuel pump problems

Postby Aaron » Thu Apr 25, 2019 8:42 am

Unfortunately it will not work that way. Your mechanical fuel injection pump produces several thousand psi bursts and does it at precisely the right time during each cylinders' combustion stroke.

You will need to unhook your internal governor linkage (accessible through the crank vent plate (highlighted below). Then you can just unbolt the pump and carefully remove it.

What is your old pump doing that makes you think it is bad?

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Kavaman
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Re: YM336D Fuel pump problems

Postby Kavaman » Thu Apr 25, 2019 12:40 pm

Aaron wrote:Unfortunately it will not work that way. Your mechanical fuel injection pump produces several thousand psi bursts and does it at precisely the right time during each cylinders' combustion stroke.

You will need to unhook your internal governor linkage (accessible through the crank vent plate (highlighted below). Then you can just unbolt the pump and carefully remove it.

What is your old pump doing that makes you think it is bad?

1.jpg

Hi Aaron, thanks so much for your help in this matter. It started with water in my fuel. I drained everything out, cleaned things and put new clean fuel in with a new fuel filter. I bled the air out of the system and will not start. when I disconnect the 3 metal lines that come out of the fuel pump and crank the engine, nothing comes out, not even a drop of fuel. Does this mean that the fuel pump is bad? Thanks again.

Kavaman

Aaron
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Re: YM336D Fuel pump problems

Postby Aaron » Thu Apr 25, 2019 12:47 pm

It sounds like you are probably right (water is very bad for those pumps) but you might try the tip in the link below just to be sure. You are cranking the engine with the throttle lever at full throttle?

https://www.hoyetractor.com/support/kno ... article=12

Kavaman
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Re: YM336D Fuel pump problems

Postby Kavaman » Thu May 02, 2019 2:57 pm

Okay, now I have the new fuel pump, is there anything I should know before installing it. What are the shims for and how do I know if I need to use the shims? Any other info that I should be aware of would be great. Thanks.

Kavaman

winston
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Re: YM336D Fuel pump problems

Postby winston » Thu May 02, 2019 5:10 pm

Shims change timing. I would install it with the same shims that came off the old one. After bleeding air crank it up and if it runs fine then don't worry any more. This thread shows timing procedure if you need it. viewtopic.php?f=1&t=7628&p=27417&hilit=timing#p27417

Kavaman
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Re: YM336D Fuel pump problems

Postby Kavaman » Wed May 08, 2019 7:31 pm

Hi, I have put the new fuel pump in and got all the air out of the fuel system. I was able to start the tractor but the governor linkage seems to have a problem. When I changed the fuel pump I disconnected the governor linkage, all I did was lift it off the pin, there was no clip or anything to hold it in place. I put the governor linkage back on and started the tractor and it went full throttle and would not stop. I stopped the engine and then I took the plate off and inspected the governor linkage and it was off the pin. I think there is something that holds it in place so it will not come off. This is what I need help with now. What is supposed to keep the governor linkage on the pin of the fuel pump. Thanks.

Kavaman

winston
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Re: YM336D Fuel pump problems

Postby winston » Thu May 09, 2019 6:37 am

https://partscatalog.deere.com/jdrc/sid ... d/17519886

Thinking parts 12 & 13 here. Hoyes would likely have them.

Aaron
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Re: YM336D Fuel pump problems

Postby Aaron » Thu May 09, 2019 7:55 am


Norm
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Re: YM336D Fuel pump problems

Postby Norm » Thu May 09, 2019 8:16 am

For a $500 pump I would go to all lengths to repair the old one. If not pumping at all, the pump cylinders are frozen in the "up" position, against spring tension.Soaking in PB Blaster and hammering-on, (prior to disassembly) is in order.


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