Hi very helpful people As the title says it won’t rev up. I drained the fuel tank, not too bad, some rust in the beginning then clear. Changed the air and fuel filters, no luck, same problem. Then on a search of this forum found the dreaded return line blockage. It’s the first fitting before the return line elbow on top of the injection pump (part number A47066). As the pictures show, it seems to have a piece of clear plastic blocking it. Is that suppose to be a check valve of some sort, the engine revved up when I started it without that fitting in the line. Thanks Ron
There is a clear ball in that fitting but that gets pieces of material from a failing flex ring around it, you are headed for an expensive repair if you delay having the ring replaced, Running it could be very costly if the head and rotor are scrapped by not having the ring replaced.
Aside from no rev problem does it run for a while then die,then restart after a couple minutes,then die again??
The rubber ring is a wait retainer for the governor fly weights.
With that clogged fitting in the return line the engine only idles, if I increase the rpm's it stalls. If I reattached the return line without that fitting the engine runs fine, revs up.
That whole stalling thing is probably your return line clogging and causing back pressure which doesn't let any more fuel through the pump..I would suggest blowing air through return line to tank,but if the machine runs fine without the check valve I think you've got a retaining ring disintegration issue like Mel said...pull the top cover from the injection pump and look for a bunch of coffee ground looking crap...if present pump needs rebuild...