# Universal M25XP / Kubota D950 question



## kaptaindave (Feb 10, 2003)

Ok... so here's the deal. I have a M25XP that's seized and a running Kubota D950 tractor motor. There is countless information on the 'Net about the fact that the M25XP is a marinised D950 and for the most part, everything's been a direct swap. My main issues is setting the valves.

Believe me, I've set valves before. I know you always do it with a cold engine. In fact, on Wednesday I set the valves on my freind's 2 cylinder universal diesel and it ran great when I was done!

Specifically here's the problem:
1) the flywheel just has a single TDC marking (label 1TC) and serveral other grooves some marked "10" and "20". I would think these other marks must be for injection timing ok fine. No problem here.
2) with no transmission on the engine there's no transmission bellhousing notch to line up, I had to get creative. The injectors were already out so I could see the top of the cylinders. So I turned the flywheel by hand until Cyl #1 (the one closes to the v-belt) is in compression and then looked at the flywheel notches. Nothing on the back of the engine looked like a timing mark at first until I noticed a raised stud (at 11 o'clock)on the back of the engine... right inline with the flywheel. It was nowhere near the factory mark on the flywheel. So I rotated the engine counterclockwise when facing the flywheel until the stud lined up with the #1 mark. And then I realized that it was #3 that was really at top dead center. Ok... now we're getting weird. 
3) Then I got out my feeler gauge. #3's exhaust valve gap was at .014 and intake valve was .000. Strange. My knowledge of Universals is that both are suppose to be .007 when the cylinder is in compression. I put an injector back into the cylinder #3 so I confirm it was in compression. I turned the flywheel around twice... exhaust then compression... to confirm this. It was. Ok now it's getting really weird.

For those that are wondering, the flywheel has never been off this engine. Heck, the injectors and even the valve cover have never been off this engine!

*Questions:
1) Where is the timing mark on a Kubota D950 ( or D850 or D750 which all same stroke)? 
2) Is it really possible that Kubota number's the cylinders different that Universal? Could 1 and 3 really be reversed?*
*3) I understand the whole concept of "rocking the rockers" until they're at their most open and watching the valve open and close to confirm which is exhause and which is intake. Again, I literally just did a valve adjustment on a 2 cylinder Uni!* *What other tricks should I know?*


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## erps (Aug 2, 2006)

Universal Diesel Engine Owners Manual - Fuel Injection Timing - Marine Diesel Direct / Torresen Sailing Site

Looks like the mark should align with a hole in the bellhousing at TDC


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## kaptaindave (Feb 10, 2003)

*No Bellhousing*

This engine had no transmission. I refered to that same drawing when I set the valves on my friends 5411!


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## kaptaindave (Feb 10, 2003)

Hey wait a minute. Just looked at the link again. It says the gap should be .145. That's gotta be it. Oh and if that mysteries raised ?timing? mark is at 11 o'clock, then perhaps something lines up at where the bellhousing hole is when I bolt this together. You know... 3 cylinder engine should have TDC at 120 degree interval, right?


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## kaptaindave (Feb 10, 2003)

*Update... still not right... different problem*

Ok... I misread the clearances last time. A gap of .007 IS fine. The marking of 1TDC IS really 3TDC. That little raised bump at 11 o'clock on the engine's rear vertical HAS TO be the timing mark as the engine is TDC when the timing mark lines up there on the flywheel.

It seems now that the problem is that the fuel injection timing is off... and THAT'S causing the noisy valves. While cranking the engine over by hand I noticed the fuel being delivered to each cylinder at TDC... not at 25 degrees before top dead center. I understand, in principle, about shiming the injection pump but if each shim equals 1.5 degrees... that would mean I need 16 or 17 shims to get the timing to where it needs to be. That seems like a lot of shimming.

Today I'm going to pull out the injector pump of both engines and 1) measure the thickness of each's shim and 2) see if I can figure out where the lobes of the fuel cam shaft area. If they're in different spots, I might have to figure out how to adjust the fuel cam itself.  I really hope I don't have to tear inside this engine.

Has anyone on here done this conversion before? Except for this hiccup, I really think I'm in the home stretch!


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## erps (Aug 2, 2006)

I would be very skeptical about the fuel injection timing changing by itself. Was the tractor motor running when you got it? Has the injector pump been removed/changed? You say you notice that the fuel is being delivered at TDC. I guess I wouldn't automatically assume there is a problem based on this observation alone. If it were me, I would finish swapping parts and then start it up. If it starts and runs fine, the timing is probably good. If it doesn't start or run good, then I would start my further troubleshooting.

By the way, how much did you get the tractor motor for?


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## kaptaindave (Feb 10, 2003)

After getting the starter rebuilt and rewiring the engine to ABYC standards, tractor motor started up fine. It did, however, cough a little smoke when I revved it up. The smoke was black with a ting of blue. The valves didn't sound loud then but I figured I better check their gap. They were _ridiculously_ off so I changed them after making my notes... figuring that and some Seafoam later would clear the carbon build up in the cylinders / valves area.

I agree... fuel injection timing doesn't just change itself but perhaps the needs of a farmer's engine aren't the same needs of a sailor's engine. No matter what, cylinder #3 is at TDC when the 1TC mark lines up with that bump.

As for dealing with this at the end, I'm pretty much at the end. All that's left is changing the transmission dampener & adapter at the flywheel, paint and an oil change. - D

PS The M25XP was pretty much given to me. The tractor motor I bought / traded for with a bunch of other stuff.


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## reynoldsnumber (Oct 7, 2003)

*universal xp25*

Where does one obtain a reasonably priced starter and solenoid for the universal xp25? Thanks


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## captainmarts (Dec 2, 2009)

*D950 gearbox question*

Hello,

Sorry if this is the wrong place for this - but there seems to be some people here knowledgable about the Kubota d950. My gearbox has packed in and I am wondering what the cheapest way would be to get up and running again.

I have the option of buying a new SAE housing and fitting a PRM80 from Lancing Marine in the UK (boat is in Gibraltar). All up its looking like it would cost around £700.

Can anyone suggest a viable (prefereably cheaper!) alternative?


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