PoA Jet Ski Project

Very large screwdriver on the lip of the inner seal, once you have the new seal. It'll pop right out.

Clean the races and inspect for pitting or rusty lines. You can sometimes clean them with some 1500 fine grit wet sandpaper, or just knock them out and replace. If they look good just leave them in. Your bearing pictures look ok from here, clean them better, don't use a rag.
 
asechrest said:
Passenger side, outside bearing is out. Looks alright to me to be honest.

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Trying to get the grease seal out now. Gotta rewatch videos. Don't know how it comes out. Also do I have to replace the races?
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If you are not replacing the bearing, you are not replacing the race. The way I get the seal out is remove the outer bearing, stick the nut back on, catch the inner bearing on the nut, then use a yank to pop the seal out with the inner bearing.
 
OK, the worst part of this job is the $@%@&# cotter pin. Doing the other side now.
 
I am done for the night. I got both sides apart and inspected. Tomorrow I'll need to pick up new bearing seals, grease, a grease gun, and new cotter pins.

The tires are nylon and really don't look too bad overall. I think I'll pick up a spare, can press my luck with the trip on the existing tires.

Thank you everyone for the help so far.
 
asechrest said:
I am done for the night. I got both sides apart and inspected. Tomorrow I'll need to pick up new bearing seals, grease, a grease gun, and new cotter pins.

The tires are nylon and really don't look too bad overall. I think I'll pick up a spare, can press my luck with the trip on the existing tires.

Thank you everyone for the help so far.
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Good. When setting preload, if you are going together with the old bearings and you can't manage to pin it exactly where you want it, set them looser. New bearings you set them tighter.
 
Well, my friends, I think I am done. I wanted to reuse my bearings, but I had a bear of a time finding the right sized grease seals. I finally found one at the fourth auto parts place I went to, and had to buy a bearing kit to get the second one. I cleaned and repacked the bearings and reinstalled everything. I put the bearing buddies back on and refilled them until I saw a bit of movement in the piston. Then it took it for a test drive and all seems well.

Then I made a midnight trip to Walmart. I picked up a $32 full size spare tire, and a u bracket tire mount, and mounted to the trailer frame. So, I am hoping for a successful trip tomorrow night. I'll let y'all know if I have a wheel bearing failure. :D

Thanks again everyone.
 
You're gonna be fine. When you put on > 100 miles, have a glance at the inner hub and look for any grease flung out once it's been hot for a bit. Check it at a gas stop. The inner seal is easy to damage putting the wheel back on, but it'll be easy to see if there's grease flung out to the inside of the wheel or fender.
 
To be clear, you did not use the new bearing, or if you did, you also changed the race, right?
 
docmirror said:
You're gonna be fine. When you put on > 100 miles, have a glance at the inner hub and look for any grease flung out once it's been hot for a bit. Check it at a gas stop. The inner seal is easy to damage putting the wheel back on, but it'll be easy to see if there's grease flung out to the inside of the wheel or fender.
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Wilco. I saw that suggested on a video too.

Henning said:
To be clear, you did not use the new bearing, or if you did, you also changed the race, right?
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Correct, I just poached the seal from the kit. I considered using the new bearing set but didn't want to mess with the races. O'Reilly actually sold me two seals. I had the thought to open them in the car and one was the wrong size (too thick). Went back in and looked at the higher priced version and they were all also too thick, even though the same part number. He had no idea why. There bearing kits has the correct seal so he sold me one at a discount.
 
asechrest said:
Wilco. I saw that suggested on a video too.


Correct, I just poached the seal from the kit. I considered using the new bearing set but didn't want to mess with the races. O'Reilly actually sold me two seals. I had the thought to open them in the car and one was the wrong size (too thick). Went back in and looked at the higher priced version and they were all also too thick, even though the same part number. He had no idea why. There bearing kits has the correct seal so he sold me one at a discount.
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Good. Now you have a spare bearing. Just making sure you didn't put a new bearing into an old race.
 
I made it. No issues with the bearings. Thanks all. I even stopped a number of times to take a look at them and see if they were hot to the touch, and they were actually relatively cool. I did use about a quarter of a tank more gas than is typical for this trip, and it took an additional hour.

Also my passenger side running light only is not working. I have to diagnose the issue soon. I will probably just replace the light and double check the wiring.
 
Weather was bad on Saturday. But on a whim we went out to the lake Sunday. Had a good few hours of fun.

But wait, there's more. After a couple hours I am out on the ski with little man and I notice different throttle response and loss of top speed. Came back to shore, popped off the seat, and the hull is full of water almost to the bottom of the ebox. I pulled the ski out and drained it. Put it back in and had the same level of water in about 20 minutes. Day over.

At the lake I'm thinking leak from outside in. But when flushing it in the driveway I had water building fairly quickly in the hull so I believe it's probably in the exhaust/cooling system. After shutting off the water and killing the engine, I think I could hear the source of the leak -- whatever that may be -- dripping down into the pool of water to the left of the engine. So that's the exhaust pipe and manifold side. A flow of water wasn't visible to me after a little looking, but I ran out of time. It'll be a week before I can mess with the ski so in the meantime I'll get familiar with the exhaust and cooling system.

I see what ya'll mean about boat ownership. :D
 
asechrest said:
Weather was bad on Saturday. But on a whim we went out to the lake Sunday. Had a good few hours of fun.

But wait, there's more. After a couple hours I am out on the ski with little man and I notice different throttle response and loss of top speed. Came back to shore, popped off the seat, and the hull is full of water almost to the bottom of the ebox. I pulled the ski out and drained it. Put it back in and had the same level of water in about 20 minutes. Day over.

At the lake I'm thinking leak from outside in. But when flushing it in the driveway I had water building fairly quickly in the hull so I believe it's probably in the exhaust/cooling system. After shutting off the water and killing the engine, I think I could hear the source of the leak -- whatever that may be -- dripping down into the pool of water to the left of the engine. So that's the exhaust pipe and manifold side. A flow of water wasn't visible to me after a little looking, but I ran out of time. It'll be a week before I can mess with the ski so in the meantime I'll get familiar with the exhaust and cooling system.

I see what ya'll mean about boat ownership. :D
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Was it only leaking when running, or sitting as well? Also remember they sit lower in fresh water.
 
Yeah, it's a boat, just a small one. Same mx issues with any marine system.

Big problem with cooling leaks is that when running the engine you are actually PUMPING water into the hull, so it can come up fast. Use your flush kit without the engine running, and see if you can get an inspection mirror down under the pipe with a small light and sort it out. Rubber bellows are common places, and also where the manifold joins the expansion pipe. Also, don't forget there's a pee tube that leads to the hull fitting. Do you recall way back when I said you need to see warm water coming out the pee tube? This is why, another place to check.
 
Henning said:
Was it only leaking when running, or sitting as well? Also remember they sit lower in fresh water.
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That's a great question that I didn't have time to test. I was behind the 8-ball all weekend. Didn't even really have plans to go out on Sunday. I may shoot for next Sunday to launch and just let it sit to see if it leaks. But my driveway test would seem to indicate at least part of the problem is exhaust/cooling system (and also that this is a new issue; I've never had water in the boat when flushing).
 
asechrest said:
That's a great question that I didn't have time to test. I was behind the 8-ball all weekend. Didn't even really have plans to go out on Sunday. I may shoot for next Sunday to launch and just let it sit to see if it leaks. But my driveway test would seem to indicate at least part of the problem is exhaust/cooling system (and also that this is a new issue; I've never had water in the boat when flushing).
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I had a leak in mine, on a big u ish looking pipe that runs basically under the rear seat. I patched the leak in the metal pipe with a high temp jb weld ish stuff. That held fine until I eventually saw a deal for one on eBay that I bought.

I'd start with running with a hose, shouldn't be too hard to find the leak, probably corrosion.
 
Looks I may get some of the mechanical experience I was looking for when I first bought the ski (vs. electrical which is what the problem originally was).

docmirror said:
Yeah, it's a boat, just a small one. Same mx issues with any marine system.

Big problem with cooling leaks is that when running the engine you are actually PUMPING water into the hull, so it can come up fast. Use your flush kit without the engine running, and see if you can get an inspection mirror down under the pipe with a small light and sort it out. Rubber bellows are common places, and also where the manifold joins the expansion pipe. Also, don't forget there's a pee tube that leads to the hull fitting. Do you recall way back when I said you need to see warm water coming out the pee tube? This is why, another place to check.
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I'll pick up an inspection mirror as a new tool in my growing arsenal. There was water from the pee hole both on the lake and in the driveway.

jesse said:
I had a leak in mine, on a big u ish looking pipe that runs basically under the rear seat. I patched the leak in the metal pipe with a high temp jb weld ish stuff. That held fine until I eventually saw a deal for one on eBay that I bought.

I'd start with running with a hose, shouldn't be too hard to find the leak, probably corrosion.
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Yeah, time for some driveway work. I need to find the actual source of the leak.
 
Oh, and it sort of hit me on Sunday: this puppy will SINK if it wants to. :lol: Would an electric bilge system have kept up with 6+ inches in 20 minutes?
 
asechrest said:
Oh, and it sort of hit me on Sunday: this puppy will SINK if it wants to. :lol: Would an electric bilge system have kept up with 6+ inches in 20 minutes?
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I seriously doubt it would sink even if the entire engine bay is full of water. They have a bunch of foam in them. I think that may be a coastguard requirement.
 
asechrest said:
That's a great question that I didn't have time to test. I was behind the 8-ball all weekend. Didn't even really have plans to go out on Sunday. I may shoot for next Sunday to launch and just let it sit to see if it leaks. But my driveway test would seem to indicate at least part of the problem is exhaust/cooling system (and also that this is a new issue; I've never had water in the boat when flushing).
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Yep, exhaust systems rot out, typically they are 5 year items around salt water regardless of how well you flush. The erosion and damage happens while running. Take it all apart and do an IRAN on the system, because if one part has failed, 3 more are about to. It's kind of a PITA because of the working space, but it's gotta be done.
 
asechrest said:
Oh, and it sort of hit me on Sunday: this puppy will SINK if it wants to. :lol: Would an electric bilge system have kept up with 6+ inches in 20 minutes?
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Shouldn't sink all the way, even the smallest electric bilge pump would only be coming on sporadically to deal with that. They typically rate over 8 gallons a minute/500gph.

However, putting an electric bilge pump on the engine battery has some risk. As long as the engine starts, you have a pump that will keep you from sinking on the way home. If you aren't paying attention, the electric pump can kill your starting battery.

I add a 2nd small battery to hook to pumps.
 
jesse said:
I seriously doubt it would sink even if the entire engine bay is full of water. They have a bunch of foam in them. I think that may be a coastguard requirement.
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Ah, that's probably true. I bet it'd roll, though.
 
A vast majority of the pre-2000s jet skis don't have electric bilge pumps anyway. Most use a siphon tube which uses vacuum off of the pump, but that only works when the engine is running. It's not much of a high-volume system, though. I'd be investigating the water tube going from the engine to the water box as well as the feed line coming from the pump to the engine cooling system. Those two items will be under pressure when the engine is running, which will cause the bilge to fill up much more quickly when running, than when sitting with the engine off.
 
Ectually, the entire cooling system is pressurized all the way to the discharge into the exhaust stream with the engine running. The water can come from anywhere in the circuit, but exhaust is more common.
 
Yep, of all the places it can happen, the exhaust is usually the first to go. :lol:
 
In the two minutes I had to stare in the engine bay and then put my ear to it and listen after flushing, it is my belief that the puddle was building, and the dripping sound was coming from, the expansion chamber area. I need a lot more time to look, but if that's correct, we're looking at expansion chamber, exhaust pipe, exhaust manifold, and associated hoses and hardware.

View attachment exhaust_diag.pdf

View attachment cooling_bilge.pdf

View attachment cooling_flow.pdf

I was looking at diagrams tonight. I don't fully understand the cooling system flow diagram. Do I have this right:

Water intake from the jet pump housing area, to the exhaust manifold to cool the cylinders, part of that branches off to the stator(?), the rest flows up the exhaust pipe (u-shape), some branching off to the temp sensor and out the pee tube, the rest flowing down into the expansion chamber (meeting with the bit from the stator), to the water box, then out the exhaust port in the back. Although now that I think about it, it wouldn't make sense to cool the stator with hot water flowing from the manifold, so the intake flow must branch off before that and head to the stator.

So I'm missing that little cooling outflow line that seems to lead from...the expansion chamber exit area? and out just below or to the right of the jet pump. What is that?

And I'm missing the bilge system, which I see but don't quite understand. I guess it uses suction from the water outflow to pull water from the hull when under power?

[EDIT] - Here, so you don't have to download the PDF of the flow diagram:

Screenshot from 2015-07-20 23:16:45.png
 
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The water enters the hull aft of the impeller in a high pressure area of the pump. It's drawn off and fed through the deliver line up into the exhaust where it is pre-heated to approx 160F.

It exits the exhaust, and goes into the stator cover which is also the manifold for the distribution of cooling flow. One branch goes into the cyl base, and through the cyls and up through the head. That water exits the head on the hose, and dumps into the outlet of the top of the exh manifold where it will later mix with exh gasses and be blown out with the exh from the expansion chamber.

The second branch goes directly to the exp chamber and cools the outside, and then that too dumps into the exh stream and is blown out the exh with the gasses. The third circuit goes through the temp regulator(that little stub valve in front), off the front of the exh pipe and from there depending on temp it's blown out the pee tube. The amount of water flowing in the block and heads is dependent on the heat of the incoming water, the heat load of the engine, and the temp of the exh gasses that pre-heat the incoming water. In very cold water, at low operating load, the pee tube will be dumping a lot of water because the thermal load will be very low. In hot water, with high speed runs, the pee tube may not flow at all because all the water is being used to cool the engine and exh manifold.

At the bottom of the exp chamber, at the lowest fluid point in the system is the drain out so that no water is left in the ski after shutdown. This is important because we don't want to have water left in the ski when it freezes which would burst the engine jacket or head. I think this is the line you are missing, and it's important to have because you don't want water dumping out the lowest point. It must be connected to the expansion chamber fitting on the bottom and lead to the discharge vent.(shown just under the impeller in the pic)

The last part, with the little box and the riser tube is the bilge drain, and it operates on the low pressure side of the pump so that any water collected in the hull goes up the riser, and then out the back by suction.

Don't let the small size of the hoses fool you, that thing flows gobs of water. The axial jet pump at full throttle pumps ~20 gal/second. That is, it will fill a 55 gal drum in 2.5 seconds. The take off for cooling is only a small fraction of that, but if you put the ski in the water, and take off that supply line, you'll see water coming through like a little fire hose.

<edited for clarity of the temp regulator water, which comes off the exh pipe to the thermostat valve.>
 
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Correct about the factory bilge system, normally uses one or two hoses in the bottom that use suction from low side of the jet pump to draw out water. Just make sure they are clear of debris (most have strainers on them). It's designed to remove a few gallons of water from burying the ski in a wave or tipping it over. It won't keep up with a steady stream of incoming water, especially not coming from the engine. It's better to pull the drain plugs and ride around to drain large volumes of water if needed. Just remember to cut the engine and out the plugs in immediately upon coming to a stop!
 
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This is also an opportunity to look into higher performance chambers and pipes... :D ;)
 
asechrest said:
I see what ya'll mean about boat ownership. :D
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Old boat ownership yes. I'm now selling my 2004 Kawasaki STX-15F after 11 years of ownership. I bought it brand new and now it has just shy of 450 hours. It's been all over the damn state and in all kinds of water. Very little head aches. Just scheduled, routine maintenance for the most part.

I did have a bizarre failure two years ago where a factory defect in the hull manufacture caused a failure of the oil pan gasket. It required me to pull the engine to fix and it was cheap in terms of parts cost, still not too bad after 9 years of service.

Buy new and the head aches are minimal has been my experience. Just got my brand new 2015 Yamaha VXR and 20 hours has already slipped by. Simply awesome boat so far. The key is to keep it long enough to get your moneys worth.
 
On the low point drain discharge, there is a 90deg fitting as I recall. With the line taken off that fitting, take a piece of bailing wire, smaller than a coat hanger, and wedge it up in there, and scrog it around. This is an area where debris collects. If you can get some of the debris out with that, it's good. Next, clamp a rubber line on it, then blow backward up the line and into the fitting and then the exh so that any crud blocking the bottom is cleared from the drain. Much like blowing back up a drain line to clear it of ladies hair. If you want to take off the exp chamber exh connector you can then clean out and crud in there with a small vac hose. Put the line back to the drain outlet, and maybe test it with some water. If you are in FL, it's likely never going to freeze, even if that drain line is clogged, but if it does freeze, you are well and truly screwed.
 
We still have the '98 Kawasaki 1100STX which runs like a champ. We don't take it out much anymore, but it's been nothing but fuel/oil and an occasional battery for the past dozen years. Just pull it out of the lake (never been in salt), blip the throttle a few times to clear out the water box exhaust and shut it down. Never bothered winterizing aside from fuel stabilizer as it's a 2-stroke.
 
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My Kawa 900ZXI has run flawless for years. It gobbles batteries every other year, and uses a ton of gas, but it's the Energizer Bunny as long as the tank is full.

Does anyone know a battery that will last longer than two years? I condition them every winter, and keep them on a float, but by the third year summer, they are still dead, dead, dead.
 
Dav8or said:
Old boat ownership yes. I'm now selling my 2004 Kawasaki STX-15F after 11 years of ownership. I bought it brand new and now it has just shy of 450 hours. It's been all over the damn state and in all kinds of water. Very little head aches. Just scheduled, routine maintenance for the most part.

I did have a bizarre failure two years ago where a factory defect in the hull manufacture caused a failure of the oil pan gasket. It required me to pull the engine to fix and it was cheap in terms of parts cost, still not too bad after 9 years of service.

Buy new and the head aches are minimal has been my experience. Just got my brand new 2015 Yamaha VXR and 20 hours has already slipped by. Simply awesome boat so far. The key is to keep it long enough to get your moneys worth.
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Yep, if you want new, the best thing to do is use the heck out of it and have a bunch of fun, that's how you get your money's worth. I've been reasonably impressed with the products from Yamaha, you should enjoy the new one.
 
Damn, there's a lot more going on there than I realized or had even considered. Part of that is because I don't have an adequate internal picture of how engine cooling works. But this is fun to learn.

Doc, great writeup. I guess i could be looking at anything from a busted or loose hose, to a hole in a component (a la Jesse), to a bad gasket between, for example, expansion chamber and exhaust pipe. I'll probably start work next week, two at most I think.
 
asechrest said:
Damn, there's a lot more going on there than I realized or had even considered. Part of that is because I don't have an adequate internal picture of how engine cooling works. But this is fun to learn.

Doc, great writeup. I guess i could be looking at anything from a busted or loose hose, to a hole in a component (a la Jesse), to a bad gasket between, for example, expansion chamber and exhaust pipe. I'll probably start work next week, two at most I think.
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You have an entire system of components, each within a few percent of end of life. Pull the exhaust apart and evaluate every component, then decide how to proceed.
 
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