I could really use some good advice--what a mess - PWC Forum: The best hang-out for Personal WaterCraft enthusiasts

chwtom · 08-13-2011, 08:34 AM

I bought a waverunner that doesn
t work

Ernest T · 08-13-2011, 09:44 AM

You are right, a bad impeller and/or wear ring could reduce your speed and cause cavitation, but it should have nothing to do with the engine dying. You can check the impeller to wear ring clearance to see if there is a problem (generally you want a gap less than 0.5 mm). On skis it is rare for the impeller to need replacement unless it is dinged or dented. Much more common for the wear ring to need replacement, especially on SeaDoo models since they design them that way. New wear rings are relatively inexpensive and not that hard to replace. You have other issues as well.

There are many possibilities for the stalling and poor running. I think that engine is fuel injected as well as direct injection for the oil, so the fuel injectors or just a fuel flow issue could be the problem...........there are a number of knowledgeable SeaDoo guys on this forum that can probably advise you.

Did you check the compression before you bought the ski.............mandatory on a used 2 stroke, unless you like surprises? I'd definitely check it now. That would give a clue as to how much work you may be looking at. You might have a worn out engine that could be very expensive to repair.

I've seen far more problems with skis that have been sitting in someones garage, etc., than ones that have been run to death. When I see one for sale that says that its not been run in several years, the hairs on the back of my neck stand up.

chwtom · 08-13-2011, 10:52 AM

Thanks for the reply. I talked to the repair guy again. He said the rear cone was missing, and that allowed some fluid to leak out that caused the jet pump to seize around the impeller shaft. He said that is why the ski wouldnt start.

He said the impeller wasn't shot, the edges were just "rolled". He said that it wasn't mandatory to replace it, I would just lose a few mph of top end speed, which isn't super important to me. He said they could just file the edge down.

They haven't checked the compression yet, but I'll ask him to. What do I do with that info once I get it? Is there a certain number that you want?

Ernest T · 08-13-2011, 12:33 PM

Now the explanation makes more sense. If the pump seized that could explain all your symptoms. If the edges of the impeller are rolled, I'd replace it. Otherwise you the ski will be less efficient (you will burn more fuel), it may cause cavitation on take off and be a slow starter, etc.. $1000 still sounds high to me, but I don't know all the parts that have to be replaced.

My guess is that you would like to see around 140 psi compression numbers on a sound engine (somewhere above 130 would be good on a used engine).................SeaDoo guys correct me if I'm wrong.

chwtom · 08-13-2011, 01:58 PM

They checked the compression and they were 136 and 138 or something like that. He said that was in range.

appreciate your help on this ernest.

YamaDoo · 08-13-2011, 02:52 PM

I know it does not help you now but you should always test ride a PWC before buying it. The compression turned out ok, so that's good. If the impeller is damaged I'd replace it, otherwise you'll have cavitation, top speed, and possible vibration issues. If the guy who sold it to you is offering to pay half, that's very good. Repair it, get the money from him, and consider it a lesson learned.

chwtom · 08-13-2011, 03:30 PM

I am thinking I might see if I can sell it and get as close as possible to my money back after it's fixed. This has taken all the fun out of the purchase and it's hard to trust a machine after it left you stranded in the middle of a big lake with your kid on board.

It's a bummer, I was really excited about having it with the kids.

Anf for the record, I am admittedly very ignorant about PWCs and what research needs to be done before purchase.

Mainer · 08-13-2011, 04:10 PM

I wish I could help you with your situation, but as someone who's just gotten interested in the world of PWC, I too am new to all this. Thankfully, there are some knowledgeable folks here who are willing to help out.

However, I've been in your shoes before, and in times like this, the cause of the problem doesn't really matter all that much since frustration, indecision, etc. is the same now. That being said, all I can offer you is my two cents based on having walked in your shoes before.

I certainly understand, and appreciate, your frustration. As you stated, it can be hard to trust in an item that has let you down, and now that it's been "tainted", it can be hard to get excited about it again. I've had a sports car that I really liked and a high-end paintball marker do the very same thing to me.

Still, I don't know as I'd throw in the towel just yet. Once you fix this, you'll have a good understanding as to where it stands mechanically. That "should" give you some comfort since you have a mechanic that's spending some time on the sled.

Once the repairs are done, I think I'd give it another chance. Although, you might want to go solo for a few hours until you're more comfortable with its reliability. If something else goes wrong then I'd say you'd be justified in getting rid of it, but this may just be a hiccup in an otherwise fine machine that can give you hours of fun in the sun.

Certainly, your mechanic should be able to give you some valuable insight too, but from the compression numbers, it would appear the engine is giving you a strong thumbs up.

Also, if after a couple hours of riding you are still having doubts then at least you gave it an honest shot and can sell it knowing you're selling a good running machine.

Just a thought....