97 gsx 787 rpm limiter?

[Triggermike1986]

Hey guys! I've been working on jet skis and boats a long time but ran into an issue on my newest ski (well newest to me). Runs perfect on the trailer, you can run as many RPM's as you dare without wanting to throw a rod or something. Put it in the water, starts right up, hit the gas and it will act like it's about to launch you out of the seat. As in it will run full bore for about a second or two but no longer than that. Then still at full throttle, it will go down to what feels like a rev limiter except it won't go much over idle. No miss, no backfires, etc. If I let off the throttle for a few seconds I can nail it again and process repeats indefinitely. Carbs are clean. Fuel is good. Oil is brp brand as usual. Any ideas??

 

[tony bombardier]

My 1997 gsx is having the same problem.

 

[Mraw]

It could be a air leak from either the fuel selector or the fuel filter assembly. To test you can run the reserve from the gas tank straight to the carb.

 

[tony bombardier]

It could be a air leak from either the fuel selector or the fuel filter assembly. To test you can run the reserve from the gas tank straight to the carb.

How do I do that ? I am like new to this seadoo tech learning curve

 

[Mraw]

On the gas tank where the fuel lines are comming out, there should be a label titled "RES" take that fuel line directly to the carb, if you have trouble finding where to hook into the carb follow the fuel line off of the fuel filter assembly that goes to the carburetor then switch them.

 

[JeremyD615]

Have you tried disconnecting the red wire going to your rectifier? That’s a quick and easy thing to check off the list...

 

[tony bombardier]

Thx

 

[tony bombardier]

On dry trailer I can crank it up to 7000rpm but on water it’s only at 2800 rpm even at max throttle

 

[Mraw]

Running good on the trailer doesn't indicate much since there is no load on the motor.

 

[Matt Braley]

You guys have RAVE housings on that model (97GSX) that have not been updated. There is a service bulletin about it.

 

[RockwallRick]

I am currently running my 97 GSX directly off the reserve from the tank. I added an inline fuel filter to the carb input. Waiting for a new fuel selector valve to come in.

 

[Ckrawiec]

I am currently running my 97 GSX directly off the reserve from the tank. I added an inline fuel filter to the carb input. Waiting for a new fuel selector valve to come in.

The conventional wisdom is to NOT add an inline fuel filter to the ski as it could starve the engine of fuel. If you are purposely bypassing the fuel/water separator, then running a fuel line directly to the carb is better than adding an inline filter...however you may need to address the internal carb fuel filter once you get your hoses sorted back to a stock configuration.

BTW...the built -in REV LIMIT on a '97 GSX is 7200 rpm +/- 50

 

[kmarts]

You guys have RAVE housings on that model (97GSX) that have not been updated. There is a service bulletin about it.

The symptoms described by op aren't what's typically encountered with the 97's. At least that wasn't my symptom. There is a hesitation around 5k rpm where you have to blip the throttle to get the engine to spin higher. His issue seems to be on the low end, shooting out of the hole.

 

[etemplet]

If you are familiar with rev limiters on motorcycles and what they sound like it was pretty apparent with my RFI had issues with the rev limiter. I just wasn't sure how the skis worked. The ski hits a wall at the same RPM and has trouble getting over it. Otherwise the ski runs great. It sounds like zoom..... zoom....zoom.... zoom. That is the MPEM cutting fire. I replaced the MPEM on the RFI and had no issues after that. Mine was consistent and at 4130 it wouldn't go faster. If I played with it for a few minutes I could get it to go to full throttle. Once below 4100rpm it was the same issue. If yours is not consistent I wouldn't look to the rev limiter. Good Luck.

 

[Triggermike1986]

I tried it on reserve and the on position with the same results. however I have not tried the red wire on the rectifier can you point me to where the rectifier is at I know where the mpem is at and the coil but that's about it

 

[Mraw]

In an earlier post you said at full throttle it wouldn't go over 2800 rpm in water, to me that really sounds like your carbs need a rebuild with genuine mikuni parts. To unplug the rectifier open up the grey electrical box and unplug the red wire going to the rectifier, you can google pics of a seadoo rectifier to see what it looks like.

 

[Triggermike1986]

In an earlier post you said at full throttle it wouldn't go over 2800 rpm in water, to me that really sounds like your carbs need a rebuild with genuine mikuni parts. To unplug the rectifier open up the grey electrical box and unplug the red wire going to the rectifier, you can google pics of a seadoo rectifier to see what it looks like.

Id normally agree with you about carbs. But it doesn't miss or run poorly at all so I really don't believe it's carb related. I'm gonna try the rectifier first.