Water in MSX 140 crankcase

[KTMforlife]

My buddy got a 2003 MSX 140 for $400. It only has 93 hours but it has a few problems. He bought it not running so i took the heads off and the cylinders looked great (though they had been bored out) but there was a nasty mix of oil and water everywhere. We pulled the motor out to replace the bendix (which was rusted shut) and i took the reeds out and there was water halfway up the reeds. Tomorrow i am going to pull the bottom half off the crankcase and clean everything out. My question is what could cause it to be flooded with water? Is there anything i need to check while i am in there? I have been working on four wheelers for 7 years now but i am new to jet ski's. Any help would be appreciated!

The previous owner was no help because he bought it from somebody else broken and didnt know anything about it.

[urugol]

If you have that much water in the case, and given the previous owner bought it like that I would say your crank bearings are well and truly gone. You will need to tear that engine right down, the cause of water entering the engine is varied but most commonly if it is tipped over and not attended to quickly enough, and turned over in the wrong direction. You didn't mention if the engine turns by hand, I suspect not you may have a bent rod in there as well just tear it down and be prepared to invest in a crank at least, probably a top end as well. What makes you believe the cylinders have been bored out? These cylinders are nicasil so they don't get bored, they can be sleeved but I haven't seen any oversized applications would be good to see some pics from you.

[KTMforlife]

If you have that much water in the case, and given the previous owner bought it like that I would say your crank bearings are well and truly gone. You will need to tear that engine right down, the cause of water entering the engine is varied but most commonly if it is tipped over and not attended to quickly enough, and turned over in the wrong direction. You didn't mention if the engine turns by hand, I suspect not you may have a bent rod in there as well just tear it down and be prepared to invest in a crank at least, probably a top end as well. What makes you believe the cylinders have been bored out? These cylinders are nicasil so they don't get bored, they can be sleeved but I haven't seen any oversized applications would be good to see some pics from you.

The motor turns over by hand (with plugs out) and it does have good compression. The reason i think it was bored over is because there is scarring on the middle cylinder head from what looks like, a piece of metal got loose and got beat around every where. The pistons all look brand new and they have "1.00" stamped on them, which i assumed meant they were bored 1mm over. I am used to working on 4 strokes so it is a little different for me. I will take some pictures tomorrow afternoon.

[Mr. GP1800]

I bet someone put 85mm pistons in it from a sleeved 1200, which are the wrong pistons for that motor. Can you post pics of what you have?

[K447]

Welcome

The MSX 140 engine is unique within the Polaris watercraft engine series. It is similar to, but not exactly the same as, the red '1200' three cylinder 'domestic' motor.

The red engine is 1165cc, the MSX 140 engine is 1192cc.

The red engine has sleeved cylinders, the MSX 140 uses Nicasil cylinders. These cylinders are not rebored in the same way as lined cylinders. The best method is to have the cylinders, if they are not good, replated back to factor spec, using factory spec size pistons. I just rebuilt my own MSX 140 engine last year.

The MSX engine uses different (more expensive) pistons from the red engine.

The water cooling is routed differently, even compared to the red Ficht 1200.

The MSX 140 electrical, fuel and ignition are quite different from a carburetor red engine. The MSX 140 uses the Ficht direct fuel injection system.

Certainly you can expect the crankshaft bearings to be rusted. Even a thin film of surface rust in the crank bearings is too much and cannot be trusted at 6000+RPM and 120+ HP. The Polaris crank shafts are pressed together, so crank rebuild requires a press and some experience.

[rr44red]

SPI or SPX pistons for the 800 twin polaris snowmobile are the same and can be found on ebay for around 60.00 apeace

[KTMforlife]

I got a couple of pictures today. Unfortunately I only got 2 pictures before my phone died. They are of the middle cylinder and head. The other heads are unharmed. If you look closely on the piston you can see the "1.00".

[Mr. GP1800]

I am guessing thats an SBT sleeved cylinder. The give away to me is the visible rust. A plated aluminum cylinder has no ferrous metal to rust. They probably do something goofy to allow them to use their 85mm pistons from the 1165cc red motor.

[K447]

I can see shrapnel damage in the cylinder head surface. Looks like some pits and gouges are quite deep.

What do the other cylinders look like?

[rr44red]

looks like pieces of crank bearing.i have experienced this before

[locito007]

looks like pieces of crank bearing.i have experienced this before

Yes looks like a bottom up rebuild to get the core bearing redone and that cylinder and the other 2 should be fixed to be done to the MSX 140 specs correctly with a good set of pistons to do the job good so you can enjoy a great ski in the water doing the job right now. it is worth the time and effort.

[KTMforlife]

looks like pieces of crank bearing.i have experienced this before

Same here. I had a KTM 125 dirt bike and somehow a ball bearing worked its way into the cylinder and tore everything up. But like I said all of the cylinders on the polaris are, it's just the center head that is still messed up. I am going to get into the bottom end this weekend so ill post more pics then.

[locito007]

Good luck and enjoy working on the MSX because it is a devine ski to do a rebuild no matter how hard things seem along the way. When you have it running you will love how the hull handles, especially out in the chop.

[KTMforlife]

I have run into a problem in splitting the bottom halves to get the crank out. I have take all of the bolts out, the cylinders, and the front cover and I still can't seem to get the bottom end apart. Any hints?

[Mr. GP1800]

Tap it with a dead blow hammer to brrak the sealant bond. Although if that's a SBT motor, god knows what kind of goo they use on the cases.