DF 50 2000 bogging down

[Rweenzz]

So my DF 50 will bog down randomly, and seems to limit itself to 4000 rpm or so. It does sound as if it is starved of gas or air. I do know that I also have cooling issues, my thermostat and poppit valve are not working good, and my alarm will go off. Is it possible that my engine is not allowing itself to warm up properly because of the where the thermostat might be stuck? I believe it's my high pressure fuel pump, but thought maybe the cooling system could possibly cause this?? Otherwise, randomly hit or cold, while at 6000 rpm, engine will bog down to 4000 while cruising, and sometimes will recover, but usually won't. I have to shut engine down, let sit and start back up.., and that doesn't work all the time. Any suggestions appreciated!

Thanks!

[artdf175]

You bring up two or three issues
Overheating when was the impeller last serviced?
The full impeller kit should be replaced every two years or more often if used a lot of hours every year
Get some new thermostat gaskets and pull it out to inspect or replace
Starving for fuel can be any number of issues
Start with fuel tank venting
Fuel lines are known to go bad internally and not let fuel flow consistently
Fuel filters plugging up inspect both inline and the high pressure fuel pump filters and if you have a pre water/fuel filter -replace every year
Check some of those and report back
Art

[Rweenzz]

Thank you Art... I'll look into that.... question, if thermostat is stuck open, not allowing the engine to warm up, will that bog down a engine?

[artdf175]

The ECU will take all the sensor input and make it run pretty well even if running at less than normal operating temp so it may not be real obviou

[Moonlighter]

You possibly have several separate issues.

On the bogging down, the first thing I would look at is a fuel restriction - meaning, change all the fuel filters, including high and low pressure filters on the motor and also your separate water separating filter on your fuel line (Racor style one - you do have one of them, don't you?). When you change the Racor, tip the contents into a glass jar and check it for water or other contaminants.

I would then ensure fuel lines are all in great condition and if any doubt, replace them. And, make sure the tank vent-breather line is not kinked or the breather outlet blocked.

On the cooling system side, replace the water pump impeller and housing. Check and replace the thermostat. If you see evidence of salt buildup, you could then do a vinegar flush as well.

Also check and if necessary replace the engine anodes.