Turn up the fuel pump

[KillerRC]

The diesel shop did some research and talked to a Yanmar mechanic. They backed out the fuel screw 1-1/2 turns from stock. The mechanic said that the Ranger accelerates a lot quicker now, and gained maybe 2 mph. He said that the injectors in this engine will never be able flow enough fuel to be able to overheat the engine, so it's pretty safe to turn up the fuel without hurting anything.

Now she rolls the coal. LOL.

Polaris Ranger Diesel fuel turned up - YouTube

Polaris Ranger Diesel fuel turned up - YouTube

[soosb21]

i overheated my engine with 10psi black smoke will over heat the engine u need more air

[KillerRC]

Black smoke doesn't mean an engine is running hot.

[soosb21]

black smoke is over fueling which creates heat. its not like a gas motor. the richer a diesel runs the hotter the egts are

[KillerRC]

Anything under 1500F is fine. Mine's not near that hot.
Turning up the fuel makes a big difference. It accelerates a lot quicker. The diesel mechanic raised the RPMs up to about 3800, by adjusting that thing that looks like a little fire hydrant, above the fuel plunger adjustment screw. He said up to 4000 is about the limit for this engine. It certainly does smoke if you push the pedal to the floor, but the Ranger hardly makes any smoke and goes almost as fast if you only press the pedal about 85% of the way. So if you just don't mash it to the floor then you don't have to worry about a big cloud of smoke. The mechanic had the fuel plunger set at 1-1/2 turns out from stock. On flat ground the speedometer got up to 42 mph. Previously my top speed on flat ground was about 39. I then backed down the screw to 1-1/4 and my top speed went down to about 40, so I think I'll turn it up to about 1 3/8 and see what happens. Even at 1- 1/4 turns it still has lots more acceleration than stock, but not as much top speed as 1 1/2 turns. Anyway, I'm happy with the results. The engine isn't much warmer than it was before, even after a long drive at top speed. But I did buy a nice Pyrometer that I'll install later. I want to do some air box modifications too.

Polaris Ranger Crew Diesel on road, turned up Fuel - YouTube

Polaris Ranger Crew Diesel on road, turned up Fuel - YouTube

[wwt2]

I just turned mine up to 3/4 and man what a huge improvement. I get my k&n tomorrow so I'll get back with ya on that one. But after reading this post I'm gonna turn mine up some more. I read the ppe turbo kit directions and it said 1.5 turns out with there turbo kit so I figured 3/4 was plenty safe. But it'll be cranking out some more tomorrow

[wwt2]

I had to cut the little cover to access the fuel screw does anyone have a part number for that little cover and that special washer so that when I'm done I can put it back on. ( I'm still under warranty ).

[Slacker]

Okay class can anyone tell me why Polaris doesn't want to cover stuff under warranty?