McCormick CX105 w/4.0L Perkins

I need a little ag help. I have a friend with a McCormick CX105. I think it's a 2003 with the 4.0L Perkins Tier 1 emissions.

He has been doing some pretty heavy bush hogging and after several hours it lost power and started loping at idle. He removed the fuel filter and found nothing there, put it back on and it started it again after a short time. He put a new filter on it and it did the same thing. I suspect trash or algae in his fuel clogging the pickup tube in the tank. It's not cold enough here yet for the fuel to gel. Anybody have any experience with this?

Seen similar in tractors in our shop, yes. Deere tractors but it's all similar. Algae won't be too hard to remove. An algaecide in the tank and prepare to change filters every couple hours for a little while.

There also may be a screen in the outlet of the tank that is getting plugged over time from junk laying in bottom of tank.

Last idea is if they have a electric lift pump. It dying after running for a while and losing fuel pressure?

Thanks Todd. I'll tell him to check the lift pump.

Check inlet pressure like Todd said, but a lopey idle after it gets hot sounds like a IP to me...
Fuel gets thinner as it gets warmer and sloppy tolerances show a worn pump worse than when it's cold.

But as normal, check the easy stuff first. Algae and fuel pressure. The lift pump should suck on your finger when pumped.