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Thread: MSX 150 Water Pump
07-08-2012, 10:05 PM #1
- Join Date
- Jul 2012
MSX 150 Water Pump
I'm a new member to the Greenhulk (great forum), and have a few question after a fairly long story.
About 2 weeks ago, I started my 2004 MSX 150, (which I've had since it was new) in the driveway , and turned on the water. When it started up, it revved up to a gazillion RPM's so I shut it off, then started it again a few times before it started idling. In the meantime, I didn't turn off the water, and after a few minutes of idling, it burped a big stream of oil. I immediately shut it down, and checked the oil - which was milky. Called the dealer and they changed the oil (4 times) and the filter.
We took the MSX to the lake the following Sunday, and it started right up. Idled out past the no-wake zone and hit it. The warning light / check engine light came on, so I shut it down. Started it back up and the same thing happened again - so we loaded it back up and took it home. I checked the oil, and it was not milky, but I noticed the engine coolant was low. When I took off the cap - it had an oil slick on top of what little coolant that was left. I cleaned out the oil, filled it back up with antifreeze and went back to the lake. Same thing happened, so I called the dealer and took it back. They said the water pump was not working correctly, and it needs to be replaced.
And now for the questions:
(1) Would a bad water pump force oil into the coolant & if so - how?
(2) Do you really have to pull the engine completely out to replace a water pump (16-18 hours labor)?
Any help will be greatly appreciated. I don't want to shell out 2 grand if it won't fix the problem.
07-09-2012, 11:20 AM #2
Welcome to Green Hulk!
Sorry for your troubles. It's nice to hear of an original MSX150 owner... sounds like you've had years of good running up until now.
When starting the ski out of the water, it is not uncommon for the MSX110/150 to rev sky high before it settles down to a normal controlled idle. It is highly recommended to always start the ski with the reverse lever engaged. This will limit revs to 3400 (as it does when in reverse in the water) and prevent any high rev issues.
Do you have the Polaris hose flush attachment on your ski? Is this where you hooked up your hose?
As far as I understand, the fresh water system (where your adding water to via your hose) is not directly dumping into the exhaust of this 4-stroke ski as it does on the 2-stroke ski. It has a separate water jacket on the exhaust manifold and turbo downpipe and I don't think it's possible to backup water into the actual engine like you can on a 2-stroke (someone pls correct me if I'm wrong). So I don't think running the hose with the engine off should have caused any trouble, like it can on 2-stroke engines.
Can you explain, "burped a stream of oil"? Where did it expell this oil? Out the little hole on the cyclone oil separator (beside oil tank)? Out the dipstick of the oil tank?
So you had milky oil. Water got in there somehow. This usually happens via the oil tank which has a water circulating around it to help cool the oil. Perhaps your water pressure from your hose was too great and found a way to leak/blow through? Normal house water pressure (in your hose) is around 55-60psi... which is higher than what is normally circulating in the ski from the jet pump.
What oil level do you maintain in the oil tank? Do you have the original round oil tank? The original oil tank had improper markings on the oil dipstick. Oil must not exceed the MIN mark on the dipstick when the engine/oil is cold. If you fill to MAX mark it is too high and the oil will be sucked back into the engine. This will coat the hoses from the turbo to intercooler to intake all with oil and get on the two MAP sensors and likely ruin them. It is a big process to clean out all this oil. Flushing out the oil from the intercooler is the most challenging. Do you have any oil coating on the big hose from the turbo-to-intercooler or intercooler-to-intake?
As for oil in coolant. It could be a blown headgasket. Or it could be a leak in the oil cooler (under the intercooler) where coolant and oil flow through (separate paths) to help cool the oil. The oil runs at higher pressure so it'll leak into the lower pressure coolant and you'll see it in the coolant in the coolant resevior. So that's a possibility... but I've not actually heard of anyone with this issue. When the engine is running... and you pop the cap on the coolant resevoir and look in... do you see coolant in there swirling? A stream being pumped into the resevoir? If not, then this points to a problem with the water pump.
And yes, to get to the water pump, you do have to pull the entire engine out of the ski. It is a very involved process requiring tearing pretty far into the front of the engine. My MSX150 had to have this too. The waterpump has a plastic gear that drives it off a gear off the crank. This gear has been known to be a weak link and strip out rendering the waterpump inoperable. Later Weber engines upgraded this to steel gear.
Tell us more and we'll see if we can help you home in on the issue.
**edited to clarify oil level markings
Last edited by ripcuda; 07-18-2012 at 10:04 AM.
07-09-2012, 10:48 PM #3
- Join Date
- Jul 2012
ripcuda - Thanks for your great reply. We've absolutely loved the MSX150, and haven't had any problems until now.
I've been using the hose flush attachment for the last 6 years, and this is the 1st year I've experienced the high revving problem. Thanks for the tip about starting it in reverse. This wasn't in the user manual or in the instructions for the hose flush attachment. Too bad I didn't find Green Hulk before now!
I was screwing with the throttle when the oil burp happened. I didn't see exactly where it originated, but it was somewhere behind the oil tank - not out of the dipstick hole.
I'm not sure how high our outside water pressure is - but it's not excessive. Again thanks for the tip - I'll be sure to "slow the flow" from now on.
I do have the original oil tank, and recently read about the improper dip-stick markings in some other threads. I talked to the dealer about this, and they were aware - but nobody told me. I never received anything from Polaris either. Since the ski is with the dealer, I can't check for oil on the inter-cooler hoses.
I also didn't open the coolant reservoir while it was running. I do know the coolant was full before going to the lake. It was about empty, with oil on top when I got back. I cleaned out the oil, and refilled the coolant (about 3/4 quart), and when we got back from the lake the 2nd time - it was about empty again - with more oil on top.
Hopefully the new water pump will have the steel gear. We're headed to Lake Powell for a week this Saturday, so I'll have to trust the dealer.
Thanks again for your great response, and I'll let you know if/when it gets fixed.
07-10-2012, 10:05 AM #4
- Join Date
- Apr 2010
- Stamford CT
If the plastic gear driving the water pump has failed, the replacement will also be plastic. I don't think this has happened to you though because when that gear does fail it usually results in a catastrophic engine failure as all of the little plastic bits clog up oil flow. In the gen 2 Weber engine the gear was upgraded to metal, but the gear has a different pitch. The new metal gear will not mesh with the balance shaft used in a gen 1 engine.
Aside from the oil cooler and head gasket, the other place where oil can enter anti-freeze is through the seal on the water pump shaft. The water pump is the missing piece in the picture and as ripcuda said, it is a labor intensive project to replace a simple water pump and/or its seal.
07-10-2012, 01:16 PM #5
hi,i have had a knackered oil cooler on my msx,oil in antifreeze,
you need to pull the engine to replace,
water pump,oil cooler,turbo,head gasket, are passive points of antifreeze and oil,
check the turbo temp sender,mine melted and knocked ski into limp mode,
dont run the msx for more than 3-5 minutes on trailer even with the hose attatched,it doesnt cool the exhaust/turbo,
things will start to over heat,the msx needs o be running in lake/sea water to stay cooled at a controlled temp,,
but i would check the oil cooler 1st,before pulling the head,
you need to get it pressure tested for leaks,
07-10-2012, 10:05 PM #6
- Join Date
- Jul 2012
Thanks ride04MSX & simmy.
The mechanic at my dealer started working on it today, so I should know tomorrow or more likely Thursday - whether or not it's fixed.
Thanks for the tip about how long to run it in the driveway. I've never run it very long with the hose - just enough to make sure it's going to start and to check the oil before hauling it up to the lake.
I'm keeping my fingers crossed.
07-12-2012, 11:11 AM #7
Please let us know what you find out from the mechanic. Helps us all broaden our knowledge of these unique machines.
07-18-2012, 09:22 PM #8
Why is it needed to pull the engine to do the water pump? Is pulling the oil cooler mounting bracket and then the water pump cover not enough? Any info helps, thanks.
07-19-2012, 10:04 AM #9
Having pulled my engine... I don't see how you could get to the waterpump. You'd have to remove the intercooler first... major PITA. Then the oil cooler and mounting bracket which I don't think you can get to easily. All the bolts face forward... right next to the gas tank. Then if you did get both of those out... you still have to get all the water pump bolts out. I think you'd at least need to hoist the engine off the drive coupler and mounts and move it rearward for enough room.
And even if you did manage that, you can't remove get to the plastic gear that's probably stripped that drives the water pump without tearing whole front engine/flywheel/etc off (see pic above). It's a very tight fit in there. Not like the twin cylinder 2-strokes in a 3 seater hull. You pop the seat and see an engine the size of a basketball and think... that's it? Look at all the space! Haha.
07-23-2012, 02:50 PM #10
I have my intercooler out. Major pain there was removing the steering tree and then the cap on the end of the intercooler that connects to the water circuit. Having done that, the intercooler just slides right out the front of the craft. After looking at the mount for the oil cooler and the bracket that holds it onto the engine, and after feeling around near the bottom of the engine, I think there are only four screws that connect it to the engine? Two big ones on top facing forward, and two tiny ones on the bottom facing up? What I am trying to do is not replace the whole water pump, but just replace the seals. Mainly the ones that separate the coolant from the engine oil. Has anyone ever done this before?
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