1979 450c lost engine power

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HEY Guys, I have a 1979 450c track loader and yesterday it started losing power. The motor still runs and starts but has no power when I let out on the clutch. the motor don't die just loses power. now in neutral the motor rpms wont go above 1500. Its like its not getting enough fuel of something What do I need to check? it has a Stanadyne AR 51747 injector pump on it.

[Stan Disbrow]

Hi,

Loosen the fuel cap when it loses power. See if that vent tube has a pesky bug nest in it....

http://www.jdcrawlers.com/messageboard/ ... =2&t=13107

That's a tread with pic of the vent tube.

After that, if the vent isn't it, time to see if there is mouse turd junk in the return line from the IP....

Stan

[nrowles]

As a newbie to crawlers I just went through the same exact thing with my 450. The first thing I did was open the timing window on the side of the injection pump (I'm assuming process is same for your 450c) and there were a bunch of small black pieces of plastic like Stan is referring to. Was a real quick and easy indicator the governor ring was coming apart and the pump needed rebuilt. It's been back together for almost a week now and I have a good 5 hours in the seat and it's working great. I made sure the return line was blown out and clear.

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Thanks Guys, I found out it was the check valve on the return line where it hooks on the fuel pump. it was not opening up enough and letting the fuel through. I seen that fix on a video on U tube. I cleaned it up and got it working good. Now the loader runs fine again, Crazy that a little piece would make it lose all its power. LOL

[amoskevitz]

As others pointed out to me when I had a similar problem, (see http://www.jdcrawlers.com/messageboard/ ... =8&t=14329) there is a good chance the gunk in the check valve is from the governor ring in the injector pump breaking down, in which case your issue is likely to quickly reappear.

[Stan Disbrow]

Hi,

There was a thread not too long ago with a pic of a ring falling apart and making up Mouse Turds.

I borrowed the link for a pic within.

http://jdcrawlers.lcent.com:8000/johnde ... 09F6E.jpeg

This is a common occurance. The small bits of plastic, which look like mouse turds (hence the term), plug the return line.

Stan

[jimmydiesel]

This was on an Allis Chalmers a few weeks ago.
Mouse turds

[Stan Disbrow]

Hi,

Yep. Sure are.

That's another good place to look for those things.

Stan