WR500, is this thing really this slow?

christians89

Seaman
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Jan 13, 2011
Messages
55
Just bought a 1990 Yamaha wr500d. Yes I know its old and is not going to be nearly as fast as the newer skis but gahh this thing just seems to be going too slow! With a second passenger on it the ski wont even get on plane, same if your trying to pull a simple knee boarder. Thats like 7-8 mph max. And when theres just one person on board it will do maybe 20 mph tops. Is that it or is something wrong here? Also if you turn any it cannot maintain its speed throughout any corner large or small. The engine seems to run great, it starts very easily, and seems to rev up to a nice high rpm. The carb is clean, and has a new fuel filter. Plugs look good and has a nice hot blue spark. Maybe a impeller problem? I have checked the grate and looked into the outlet of the jet and everything seems clear. Does anyone know of any simple mods that can be done cheaply to the engine or impeller for a little more speed/power? Let me know, thanks guys!
 

cpubud

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Jun 18, 2008
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468
Re: WR500, is this thing really this slow?

I have a 93 it runs about 30 with 2 people 38 with 1 adult no problems at all slides thru the turns wife loves it.
 

cpubud

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Jun 18, 2008
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468
Re: WR500, is this thing really this slow?

yes 500 cc
 

Andre900

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Jun 29, 2011
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Re: WR500, is this thing really this slow?

I was having a similar problem, though not quite as extreme, as your's on my '97 Yamaha Wavrunner 700. The shop replaced the coil and CDI electronic control unit. Now it accelerates much better, but only reaches about 20 MPH. The shop tells me it needs a new impeller and wear ring. Look up through the intake under the ski and see if you can see the impeller. Mine is pretty dinged up.
 

christians89

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Jan 13, 2011
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Re: WR500, is this thing really this slow?

Ive looked up into the intake on mine and the impeller appears to be, likely is, the original unit. However, I dont visibly see any major defects in it. No bends or gashes into the aluminium. I did notice it looked like the impeller may have been rubbing the pump housing a little though. But I wasnt sure if that could have been done while sucking up debris or other foreign objects. I have never worked on jet ski pumps but I assume the wear ring is what would center the impeller in the housing?? Someone teach me!
 

slag

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Jul 17, 2009
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471
Re: WR500, is this thing really this slow?

The wear ring is what the impeller turns inside. It requires tight tolerance so that the water that is sucked from the intake grate will push out the back of the water with good force. The bigger the gap between the wear ring and impeller, the less thrust you will have. Ideally you want the two to almost touch so that the water cannot escape on the side of the impeller and is forced out the back. The impeller rides on the driveshaft that comes out the back of the motor. Either your impeller is worn or your wear ring is worn. I don't recall if your wear ring is replaceable or not.
 

christians89

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Jan 13, 2011
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55
Re: WR500, is this thing really this slow?

Slag, after a bit of research i was thinking the same thing. But now im left wondering if this thing is even worth putting the money into?? Does anyone know if you can still get these replacement parts? Should I upgrade the impeller while im in there or would the difference be worth it on this smaller ski? Thanks so far guys!
 

christians89

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Jan 13, 2011
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Re: WR500, is this thing really this slow?

Ok I took a closer look today. The impeller housing is worn but i wouldnt say its bad enough to need replacing. When you rub your finger across the sides it does feel rough but it doesnt seem to have enough wear to make a difference. I believe the impeller needs to be replaced, each "fin" appears to have a noticable gap between the impeller housing which leads me to believe the impeller is worn out. The edges also seem flat and aged. Any opinions?
 

slag

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Jul 17, 2009
Messages
471
Re: WR500, is this thing really this slow?

sure, you can still get replacement parts. There is also a company, impros, out of california, who rebuilds jetski props. I've used them a few times. SBT also will rebuild your prop to OEM specs. You take your impeller(prop) off, send it in to them, and then weld and grind on it and rebalance it until it is back to spec.
 

christians89

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Jan 13, 2011
Messages
55
Re: WR500, is this thing really this slow?

That sounds really good, probably gonna go that route. Thanks slag!
 

dakmatik

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Apr 20, 2010
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5
Re: WR500, is this thing really this slow?

I'm running into similar issues with one I just bought. these things don't have a replaceable wear ring. The impeller housing is tapered, and you can just space the impeller out to fit better. Also, if yours has the stock aluminum impeller like mine did, you need to pony up and buy a whole new impeller. No one will touch them if you want them refurbished.
 

slag

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Jul 17, 2009
Messages
471
Re: WR500, is this thing really this slow?

I'm running into similar issues with one I just bought. these things don't have a replaceable wear ring. The impeller housing is tapered, and you can just space the impeller out to fit better. Also, if yours has the stock aluminum impeller like mine did, you need to pony up and buy a whole new impeller. No one will touch them if you want them refurbished.

SBT and impros both will work with the stock aluminum impeller.
 

christians89

Seaman
Joined
Jan 13, 2011
Messages
55
Re: WR500, is this thing really this slow?

I'm running into similar issues with one I just bought. these things don't have a replaceable wear ring. The impeller housing is tapered, and you can just space the impeller out to fit better. Also, if yours has the stock aluminum impeller like mine did, you need to pony up and buy a whole new impeller. No one will touch them if you want them refurbished.
Does it require any sort of special shims? If I could get by with this for a while I would. Ive tracked down a parts ski and if its impeller is in any better shape ill just get it.
 

dakmatik

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Joined
Apr 20, 2010
Messages
5
Re: WR500, is this thing really this slow?

I don't believe it's anything special for shims. I'd go to your local hardware store, and find a washer that fits. It's not a perfect fix, but it works.
 
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