MSX 110 and MSX 150 (2004) with Weber turbo-charged MPE750 engine

Polaris introduced their first 4-stroke powered MSX 110 and MSX 150 models in 2004.
The 750cc turbocharged and inter-cooled engines were sourced from Weber in Germany. They are compact in size, and quite fuel efficient as PWC engines go.


Things to consider when buying a Polaris MSX 110 or MSX 150

More info related to the MSX 110 and MSX 150 PWC


Oil and oil levels
In terms of oil levels these Weber MPE750 engines are quite different from most engines people are familiar with, and this leads to errors. The service and owners manuals don't really do the best in this regard, hence the recurring problems with oil levels on the Weber engines.

Many owners worry about having too little oil in their engine. For these Weber motors, even a little bit too much oil causes problems.

Also, the stock ECU fuel mapping is very rich and results in rapid degradation of the oil from gasoline contamination (via piston blowby). Frequent oil changes are highly recommended.

There are only a couple of oils that are compatible with the Weber engine. Make sure you are using the correct oil, and have the correct amount in the engine.

Oil level markings on the dipstick are incorrect.
Too much oil in the tank causes excess oil to be pushed into engine air intake tract, where the oil contaminates sensors and reduces engine RPM and power.
It can also clog up the entire intercooler
How to correctly set the oil level for the Weber engine
Dipstick level check - Alternate description

Weber engine oil level check, Cold engine

Verify that the watercraft is level.
Run engine at idle speed for about 30 seconds. Stop engine.
Unscrew dipstick, remove and wipe off dipstick.
Place back in tank (do not screw down), then remove and read stick.
Maintain the oil level at anywhere from just on the stick up to the Add Oil mark
Any higher than this will be over filled.


How to change the oil in the Weber engine (official service manual method)
How to remove the oil filter and change the oil without using a suction pump

What oil to use - Mobile One 15W-50
Polaris Marine PS-4 Synthetic 15W-50

Polaris oil filter for Weber MPE750 engine
Updated one piece oil filter (preferred) is part number 0451842
Original style oil filter paper insert only is part number 0451430


If a Weber engined PWC is capsized, that can also contaminate the sensors with oil

What sensors need to be cleaned or replaced due to oil contamination?
Engine surging is one symptom of sensor oil contamination

If you get the plugs for the two MAP sensors swapped, the engine will pop and miss
Manifold Absolute Pressure sensor specifications


Maximum engine RPM under different conditions

How to fix a stuck wastegate on a Weber turbocharged engine

The mainfold can also be rebuilt with better lubrication

There is an updated version of the wastegate solenoid available

How to check and adjust turbo wastegate arm to actuator

The oil tank internal baffle can become loose inside
How to fix it

Using air pressure and mild heat to get the tank apart (be careful)

Weber Oil Tank upgrade Kit with Catch can

Alternative sources for the 0451353 Oxygen O2 sensors
Bosch PN 0 261 230 042. Try your local Napa or Carquest stores...

PN 2410605 is the exact same sensor but used in Polaris FST snowmobiles
supersedes 0451352

MSX 110 and MSX 150 Technical notes and Service Bulletins

MSX 150 and MSX 110 Winterizing / Storage instructions

Options for boosting power output on Weber MSX 150 engine
Offering ECU upgrades -- MSX150 & MSX110
Other upgrade options for the MSX 110 and MSX 150

MSX 110 engine (100HP? rated) can be converted to MSX 150 engine (135HP rated)

What are the technical differences between the MSX 150 and MSX 110 engines?

Weber engine ECU diagnostic plug location is mid-way on side (right side) of hull, a gray or black plug with a wire loop...


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