1991 Yamaha Waverunner III 650 troubles…

[fox river pwc]

Re: 1991 Yamaha Waverunner III 650 troubles…

Might be needed, I’ll have to see when I take it off. Do you need to remove oil tank to take it out? Clogged waterbox would explain why it’s been slowly getting worse over time. Might just try running it with no waterbox to see if that’s any better, it’ll be loud lol

I've disassembled about 70 WR3s, but I'm not even 100%.
But I am sure the it's WAY easier with the oil tank removed.
Otherwise I would bet the carb has to be removed...maybe...lol.

[fox river pwc]

Re: 1991 Yamaha Waverunner III 650 troubles…

This is why I stopped answering questions on here, I guess I just needed a reminder, thanks for that

You know fukkbookk is waaaaay worse.
Count your blessings.

[WFO Speedracer]

Re: 1991 Yamaha Waverunner III 650 troubles…

Maybe it's just me but it chaps my *** when someone comes on asking questions and then argues with those trying to help them, obviously they have no idea or they wouldn't be posting here to start with, you are right Facebook is way worse and I generally refrain from giving my input on issues such as this on Facebook. The last WRlll I had that was acting weird had a bad waterbox, it had most of the symptoms he describes , I spent hours and hours of testing and running that ski to find it, so much so that I put it in the pond at the shop and left it there instead of hauling it back and forth to the river for testing, you get the benefit of my years of experience and it cost you nothing except for a small amount of respect, do not argue with me I know of which I speak.

[Myself]

Re: 1991 Yamaha Waverunner III 650 troubles…

Damn WFO.......you need a vacation. LOL! These busy summers will do this to a fella!

[fox river pwc]

Re: 1991 Yamaha Waverunner III 650 troubles…

Maybe it's just me but it chaps my *** when someone comes on asking questions and then argues with those trying to help them, obviously they have no idea or they wouldn't be posting here to start with, you are right Facebook is way worse and I generally refrain from giving my input on issues such as this on Facebook. The last WRlll I had that was acting weird had a bad waterbox, it had most of the symptoms he describes , I spent hours and hours of testing and running that ski to find it, so much so that I put it in the pond at the shop and left it there instead of hauling it back and forth to the river for testing, you get the benefit of my years of experience and it cost you nothing except for a small amount of respect, do not argue with me I know of which I speak.

Yes, I hate people too, but keeping some of them around is a necessary evil.

[fox river pwc]

Re: 1991 Yamaha Waverunner III 650 troubles…

Now that I think of it, I also experienced a clogged/broken waterbox on a WR3 I was rehabbing a few years back. It had been put away for winter by the p.o. with a waterbox that was full of water, which cracked a baffle, which would bounce around and block the outlet when running. I was able to stick a paddle drill bit in through the inlet (I think) and chew up the loose piece enough to be able to yank it all out with a long needle nose. That fixed the issue, and it was just a bit throatier after that

[Myself]

Re: 1991 Yamaha Waverunner III 650 troubles…

Now that I think of it, I also experienced a clogged/broken waterbox on a WR3 I was rehabbing a few years back. It had been put away for winter by the p.o. with a waterbox that was full of water, which cracked a baffle, which would bounce around and block the outlet when running. I was able to stick a paddle drill bit in through the inlet (I think) and chew up the loose piece enough to be able to yank it all out with a long needle nose. That fixed the issue, and it was just a bit throatier after that

I have done that exact same thing before.

[fox river pwc]

Re: 1991 Yamaha Waverunner III 650 troubles…

I have done that exact same thing before.

So neither of us are "special".
Whew.

[WFO Speedracer]

Re: 1991 Yamaha Waverunner III 650 troubles…

Yes, I hate people too, but keeping some of them around is a necessary evil.

Shucks I guess if I just have to !

[wmazz]

Re: 1991 Yamaha Waverunner III 650 troubles…

Look at your old cdi to see if it has the Pro-Tec/Dallas Baker Products
rev limiter mod?


Bill M.

[wmazz]

Re: 1991 Yamaha Waverunner III 650 troubles…

Does the 650 have a fuel primer?

Did your engine ever backfire while you were trying to start it?

Did you use starting fluid? Did your engine previously overheat?

When you lean out the low screw, does the engine want to run away?


It is obvious that your engine was loaded up, and your spark
plugs were gas fouled (possibly JUNK). They are not new anymore.
Replace them.


Bill M.

[Colezayz]

Re: 1991 Yamaha Waverunner III 650 troubles…

Does the 650 have a fuel primer?

Did your engine ever backfire while you were trying to start it?

Did you use starting fluid? Did your engine previously overheat?

When you lean out the low screw, does the engine want to run away?


It is obvious that your engine was loaded up, and your spark
plugs were gas fouled (possibly JUNK). They are not new anymore.
Replace them.
Bill M.

now that you mentioned it, I remember earlier it was backfiring quite a bit before I sorted out an ignition problem. It has a fuel primer, also does run away if I lean the low speed screw a little over 1/2 a turn. It did also have a pro tec CDI that I removed due to it going bad.

[wmazz]

Re: 1991 Yamaha Waverunner III 650 troubles…

Your stock CDI has a really low rev-limiter of ~6500rpm. On
the trailer (without a load) it will hit very early. Probably within
1/2 to 3/4 throttle.

How it performs in the water is what counts, so here is a few
precautions. (1) If there is any leading edge rock damage on
the impeller, get it repaired (assuming it is s/s). (2) Make sure
the pump is sealed to the hull. They used to have a thick rubber
tape, or maybe use ultra silicone (perhaps someone else has a
better method). This is to prevent exhaust from getting sucked
into the pump.

Your WR3 (most likely) has a vacuum leak at the carb base gaskets
that is causing the engine to run away. You need 2 thick (.031" to
.062") gaskets on the carb base. If possible make your own. After
the thick gaskets readjust the throttle cable free play.

Even better, replace all your other intake gaskets with at least
1/32" rubberized felt, and learn the idle drop test to set your low
speed screw.

Replace your spark plugs.


Bill M.

If you modify your new cdi, keep in mind:

When Dallas created the rev limiter mod, initially it had no rev-limiter.
But with no rev-limiter, the front half of the crankshaft breaks off.
So needles to say, he added an adjustable rev-limiter.

The rev-limiter mod does not increase rpm or speed, it just makes the
WaveRunners easier to ride in rough water.

The black goo was just fuel that collected inside the water box.

A water test/power tune may be needed to determine if the waterbox
needs to be replaced.

[Colezayz]

Re: 1991 Yamaha Waverunner III 650 troubles…

Been a while but got a chance to look at the waterbox, everything seemed fine and I didn’t hear anything rattling around in it. Rinsed it out with a hose and some unburnt fuel mixed with carbon and oil came out and that’s about it. Lost as where to go from here lol

[Colezayz]

Re: 1991 Yamaha Waverunner III 650 troubles…

Your stock CDI has a really low rev-limiter of ~6500rpm. On
the trailer (without a load) it will hit very early. Probably within
1/2 to 3/4 throttle.

How it performs in the water is what counts, so here is a few
precautions. (1) If there is any leading edge rock damage on
the impeller, get it repaired (assuming it is s/s). (2) Make sure
the pump is sealed to the hull. They used to have a thick rubber
tape, or maybe use ultra silicone (perhaps someone else has a
better method). This is to prevent exhaust from getting sucked
into the pump.

Your WR3 (most likely) has a vacuum leak at the carb base gaskets
that is causing the engine to run away. You need 2 thick (.031" to
.062") gaskets on the carb base. If possible make your own. After
the thick gaskets readjust the throttle cable free play.

Even better, replace all your other intake gaskets with at least
1/32" rubberized felt, and learn the idle drop test to set your low
speed screw.

Replace your spark plugs.


Bill M.

If you modify your new cdi, keep in mind:

When Dallas created the rev limiter mod, initially it had no rev-limiter.
But with no rev-limiter, the front half of the crankshaft breaks off.
So needles to say, he added an adjustable rev-limiter.

The rev-limiter mod does not increase rpm or speed, it just makes the
WaveRunners easier to ride in rough water.

The black goo was just fuel that collected inside the water box.

A water test/power tune may be needed to determine if the waterbox
needs to be replaced.

Was not having any issues with it running away, has a new carb base gasket too. I would do the idle drop test to tune the low speed screw if it ran long enough for me to do it lol