89 yamaha WR500F-affordable upgrades

[sirdave4]

Had just recently purchased a 89 Yamaha Waverunner and was looking to spend a few dollars in some upgrades. From what I hear the easiest way to get more power out of these is to replace the stock impeller. Any opinions in what I should start off with? Thanks in advance for you assistance.

No sarcasm please!!!

[Bustoff]

Re: 89 yamaha WR500F-affordable upgrades

More air/fuel in,more exhaust out is a good place to start.

[sirdave4]

Re: 89 yamaha WR500F-affordable upgrades

Are you saying that an air filter, new carb and exhaust is the best place to start? If so, what brand do you/or anyone recommend?

[wmsky]

Re: 89 yamaha WR500F-affordable upgrades

Which impeller you buy depends on what other mods you make to to the ski. If you increase the horsepower enough it will probably require a different impeller to get the best out of the more powerful engine. So, you really need to decide on how much you are going to mod the engine first. As for impeller suggestions, go to www.impros.com. They really seem to know impellers and they have suggestions for which impeller to use for stock, mildly modiified, and highly modified engines.

Also, keep in mind, that many of the mods to your engine, besides the time and effort making the mod itself, will require you to rejet and retune the carb to keep from damaging your engine. If you don't want to do this, you might want to stay with just replacing external components, like the impeller, intake grate, ride plate, etc.

That being said, I also have an 89 WR500F, and I haven't seen a lot of aftermarket mods for the engine. I haven't looked really hard yet since I'm rebuilding the engine out of a 96 Yamaha Waveraider, but most aftermarket manufacturers seem to start with the 701 engine for Yamahas. I'm even having trouble with something as simple as an aftermarket flame arrestor (F/A). You add an F/A to increase airflow. However, when you do that, you usually need to rejet the carbs so you don't run too lean and damage your engine. However, I can't find anyone who sells replacement jets for the stock carb. I'm not even sure if the carb even has replaceable jets.

In fact, I'm hoping this thread generates some info about mods that I haven't been able to find on my own. :)

[sirdave4]

Re: 89 yamaha WR500F-affordable upgrades

Thank you for the help. I'll probably just try and replace the impeller. I was told that alone makes a big difference.

[wmsky]

Re: 89 yamaha WR500F-affordable upgrades

Changing the impeller should make a big difference. I can't imagine that the stock 1989 aluminum manufacturer's impeller can be anywhere near as good as an aftermarket stainless steel impeller made by a company that specializes in impellers. The 3 companies I hear about most often are Solas, Skat-Trak, and NuJet. I've read here that Solas and Skat-Trak give good all-around performance increases while the NuJet is aimed more at bettering your top speed.

As long as you are going to be working on that part of the ski, you might want to think about replacing or modifying your intake grate and replacing your ride plate as well. There are people more expert than me on these forums who could tell you whether it's truly worthwhile for this particular ski to change these as well, but again I've read that an aftermarket ride plate can get up on plane faster and may help you track better, and an aftermarket intake grate, or modifying the stock grate by removing one or more bars, can help keep your pump loaded better. Keep in mind though, that modifying your grate that way or an aftermarket grate will let in larger chunks of debris, so you have to be a little more careful when you ride. And the type of grate known as a "scoop" grate, while keeping your ski hooked up to rough water better, will probably scrub a few mph off your top speed.

[Bustoff]

Re: 89 yamaha WR500F-affordable upgrades

Are you saying that an air filter, new carb and exhaust is the best place to start? If so, what brand do you/or anyone recommend?

No,you would be hard pressed to find any new performance parts(exhaust/carbs,etc...) for an old WR500..What you could do is shop around and find those kinda parts;but keep in mind even with all that it still will be only a small gain at best..

Your best bet would be to maybe get a intake grate and an aftermarket impeller.


Keep in mind that 500 is actualy an outboard engine Yamaha put into a PWC..



I would love to find one(reasonable),running or not;problem is,folks around my area price em' WAY higher than they are worth..