JD 450B RPMs Bouncing when under power.

I have a 1972 JD 450B that run steady rpms on the tech when I first got it. Two years of pretty heavy work it now lopes on tech and does now hold the rpms up like it did. I've changed the fuel filters (all three), changed the voltage regulator that was fried. The air cleaner needs the outer filter changed pretty bad, but don't know if this is the problems or do I need new injectors or what? When running right this is a real workhorse and I love it, but it seams sick these days? Also can you weld on new cleats to the track pads or will this ruin the temper in then? I'm leaking pretty bad out the end of one of the lift cylinders, what's the fix, is it the packing's or something else? rolleyes:

hard to say but i would start by running the valves. and yeah you can "re-toe" the pads. they actually sell the bar stock for it. maybe someone here has experiance with it and can point you in the right direction as to where to look

Pj

By running the valves do you mean a pressure test or tearing the engine down and re-valving the engine? I guess running the valves is throwing me off, let me know. Does anyone know a really reasonable site or place to get 17" re-toe bars?

I would think Powerjoke means to do a valve adjustment. I would change the air filter ASAP. That can really affect power although I've never known a dirty filter to cause "loping", sometimes caused by speed governor needing adjustment. Keep in mind I know nothing about that engine in particular.

Now ya got me thinking it does lope when setting still and loses rpm when under power from 2200 down to 700-800 rpms. Sometimes I have to shift down, which I didn't have to before and it had plenty of power. Also, I have a Ford 600 Dump Truck with a 390 engine. We have to put gas in the carb throat everytime we start it up the first time. After it runs for ten minutes or so it starts fine all day long, till it sits again over night then back to the gas in the carb again. Also we have to keep it choked pretty much all the time which uses a lot of gas???

Check the 12 volt supply line on top of the pump for bad connection.

Sounds like the injection pump to me. I think that there is an inspection plate on the side of the pump. About 1/2 inch wide and two inches long. There should be two screws that hold it on with a rubber gasket behind it. If so, hold a rag under it and take it off. Fuel will come out (not much) catch what you can and look for debis. Any forign matterial would indicate a need for pump repair.

Thanks for the input so far I'll check out these things...Keep the ideas coming.

in general most people when they look at the price of a new shoe compared to an old shoe with new grouser welded on will purchase a new shoe , if shoe is less than 20"