Universal M25 losing power

[MarkSF]

I think we agree that it's impossible to say without knowing anything about your prop, and what cruising performance you are getting (speed vs. rpm)

[dabnis]

Don't know what the Mfr specs are but I think 10lbs of oil pressure at that RPM may be on the low side? Maybe try a mechanical gage? If it is still that low maybe a weak pressure relief valve or maybe the bearings are a bit on the loose side, or a tired oil pump? Proper viscosity oil? Are you running synthetic oil?

Paul T

[eherlihy]

Answers to your Questions:

Prop - rebalanced at the beginning of the season - Michigan Sailer 16 RH 9
Here is a pic;



at 2000 RPM I am doing ~5kts (when I am not tied to the slip)
Oil - changed about 30hrs ago. Shell Rotella 15W40
Fuel Filters: Raycor R24P 20Micron primary & WIX 33390 10Micron secondary.
The Raycor looks fine.

I agree that 10PSI was low. That is what caused my panic in the other thread. Actually, this is what is scaring me now. In the earlier thread I documented 2600 RPM (secured to the dock) as maximum RPM. It is now down to 2100 RPM when secured to the same dock.

Dino oil

[eherlihy]

If I recall correctly, the required filtration on this engine is to 17 Microns.

Also, MarkSF's Engine is also known as a Universal M30. Max RPM on his engine should be 2800.

[BarryL]

Hey,

I doubt that there is a problem with your engine. I bet that if you get the bottom cleaned and the prop cleaned you will find the missing RPM and speed.

IMHO, if the engine starts and runs well, doesn't smoke too much or use too much oil, then just keep using it. Of course, change the oil and filter once a year or ever 100 miles, and otherwise keep up on the maintenance, etc.

Barry

[Stu Jackson]

Have you removed the screen from the pickup tube in the fuel tank?

Have you corrected the fuel lines from tank to pump to Racor TO tank, Racor, fuel pump?

Have you checked the screen under the pump?

[eherlihy]

Great ideas Stu!

Screen from pickup has been removed.

Current fuel configuration is: Tank - Electric Lift Pump - Racor (30 micron) - Mechanical Pump - Secondary Filter (10 micron)- Injection Pump - Injector

I have not checked the screen under the pump... can you post a link?

Thanks!

[Stu Jackson]

Most of the OEM lift pumps were Facets. The bottom has a nut-looking protrusion. Look at the base of the pump, it has "ears" on it. Simply put a wrench or socket on the protrusion and unscrew it. Be careful not to lose the magnet inside. The screen's in the bottom, too.

FLIX!!! of NAPA Fuel Pump #610-1051

You should also replumb: tank, Racor then lift pump, to engine. Also discussed in the link.

[Stu Jackson]

Bleeding the fuel system:

I just listened to the video of bleeding. One of the interesting parts is that they suggested cracking the injector lines first, and only then referred to the knurled knob before the lines to the injectors.

On my engine (M25, D850) the knurled knob is ALL that is needed IF YOU HAVE AN ELECTRIC FUEL PUMP. It's a lot easier to turn the ignition switch on to get the lift pump working and then just open the knurled knob. No need to ever touch the injectors themselves.

Way, way back, I also posted this, right here on this forum: Universal M25 Series Engine Information

[eherlihy]

Thanks Stu!

And thanks - again - to Maine Sail for this timely HOW TO on the Facet pump (which I have) and cleaning the filer; Replacing A Facet Fuel Pump Filter Photo Gallery