Massey Harris 744d

I have a 744D (Perkins P6 motor)which has stood languishing for an extended period and a mate tried to get it going. With new fuel flowing he got it running but with virtually no power. Next time no go with no fuel getting to the injectors as if the shut off was still on, but the lever on the governor is free. I think it has a pnuematic governor.

Any suggestions?

I know nothing about these Perkins, I had a P6 once was pretty useless I thought
Is fuel getting to the injector pump at all as in does the lift pump work

Paul

Hi Mammoth, I have a 744d with a L4 engine sounds like the rod that goes through the fuel pump is stuck or not moveing, this rod makes contact with the vacuum diaphram on the back of the pump and alters the fuel delivery amount from the plungers to the cylinders. I know for a fact that if the diaphram is holed it causes the engine race and run fast as this happened to mine. I am no diesel mechanic but this is what I found after playing with my tractor. Hope you work out your problem, Cheers Graham

Its probably gravity feed,but may well have a plunger type lift pump.I think you may find that one of the injector pump plungers is frozen.(or more).Take the flat cover plate off the front of the inj pump.See if all the plungers are returning down under spring pressure,if one is stuck ,its pretty obvious.If the shutoff lever goes full travel and turns all the pumping elements ,then thats ok.

fuel is gravity fed and flows through pump ok, all the plungers are operating, so I suspect something is happening at the governor.

The shutoff lever should move approx 90deg back and forth.If it only moves a bit,the pump rack is stuck.The commonest cause of stuck rack is frozen injector plungers,otherwise,the rack is stuck in the bushes in the pump body.I will get out a pump book and refresh my memory on the exact details.