450c performance

[77 Ford]

I've got a few questions regarding performance on my little non turbo 450c loader.

1) It seems hard to start. I always turn the fuel off under the seat when not in use. Normally several days or a week or two passes before I try and use it again. If I just turn the fuel on and start cranking it takes 3 or 4 cranking sessions of 15 to 20 seconds each before it will start and then it usually dies once or twice. If i give it a 2 second burst of starting fluid in the air cleaner it fires right off and stays running every time. Is this just a sign of age or is there something wrong with my injector pump? Most of the fuel lines are new as well as the filter.

2) If I run the machine for 4 or more hours it seems that it does not run as good, the performance of the engine seems sluggish. I normally run the loader around 1700 rpm and I find the longer it's ran the higher I need to run it. I never operate it above 2,000 rpm. The temperature of the machine after these long run sessions varies between 180 and 190 which seems about normal.

I don't know if this is all normal or if I should be looking for issues. In general I'm happy with the way the machine runs but I know as it gets hotter this summer it will probably get worse. Does anyone have any opinions on this either way?

Thanks for the help.

[vestor_guy]

You are getting air in the fuel line. If you do not see any fuel leaks, I would suggest loosening the tank cap a bit and see if it makes a difference in how the tractor performs.

If the vent line to the tank is stopped up, you can create a reduced pressure in the fule tank and suck fuel back into the tank.

[jdemaris]

1) It seems hard to start. I always turn the fuel off under the seat when not in use. Normally several days or a week or two passes before I try and use it again. If I just turn the fuel on and start cranking it takes 3 or 4 cranking sessions of 15 to 20 seconds each before it will start and then it usually dies once or twice. .

Why do you turn the fuel off? Unlike a gas engine, it cannot flood. Sounds like the pump might be getting air-bound after sitting a long time with the fuel valve turned off. I doubt the problem is the injection pump. There might be minor leaks in the fuel transfer-pump, lines, injection pump, etc. When you shut the fuel valve off and let it sit- they may be enough to cause it to get air bound.

How is it when it just sits one day and you try to start?

I will note that when the C series 350 and 450s came out - machine tolerances from Deere were at their sloppiest. So, some brand new 450Cs started great down to 30 degrees F, while other brand new machines could barely start at 50 degrees F without a shot of ether.

[vestor_guy]

What appears to be happening is a vaccuum developing in your fuel tank and when you shut the engine down, fuel is pulled back out of the lines into the tank. Air then leaks through any fittings to the fuel pump, injection pump and injectors.

Just take the tank cap loose and see how it runs. Leave the tank cap loose overnight and see how it starts in the morning. If it still has problems, it is NOT the tank vent stopped up.

[77 Ford]

The vent is plugged no doubt about that, i tried in vain last night with a coat hanger to get it open. I'll have to go back with something stiffer and some carb cleaner or something to soften it up.

Do you think this could be the source of both problems or merely the starting problem?

[vestor_guy]

It would cause both problems.

to clean it out, you might try to flatten the end of the coat hanger a litttle and use a variable speed battery drill to slowly drill a little at a time as you attempt to clean the tube. Be sure to not get the wire stuck and keep the speed low.