99 GSX RFI Can't find the Problem.

[RDele]

RDele
Update: I have installed the new beefed up rectifier from OSD. Test drove it today. Still, only got up to 4520 rpm. I'm stumped.
Also, when I got home, when I was flushing it on the hose, it cut off just like on the water. No motor- no electrical. Started it back up and continued to flush. Stumped again.

Do you have any ideas?

 

[RDele]

I have replaced so many parts on this machine.
Post
Lanyard
water temp sensor
starter
start/stop button
fuel pump and two filters inside the tank
rectifier
plugs gapped at .020 NGK BR8ES
New bellows, springs, o rings, and cleaned rave valves etc.
oil filter (yes I bled air out)


Cleaned fuel injecters
adjusted lines on oil pump pulley
cleaned out the mag cover and stator
checked the fuses in the MPEM and rear electrical box
Checked the grounds on the mag cover and at engine
Checked the connections at the starter and in the rear electrical box.
Checked battery cables twisting and bending them while on continuity tester. All good connections and good wires.
Battery tests at 12.50 volts. On hose flushing the battery tests at 13.8 volts at 3000 rpm. new beefed up rectifier from OSD.
All pins look good at the MPEM.

I think that's it

 

[SabrToothSqrl]

So, you're fairly sure the issue is electronics? the compression on the engine is good? jet pump is good?

Fresh fuel, clean fuel filter, correct oil?

sometimes the 'easy' stuff gets overlooked, just checking!

Not that it's a good test, but will it rev to 7k on the trailer?

 

[RDele]

Thanks for your response there SabrToothSqrl.
I'm not sure of anything anymore with this ski. Compression is good. Jet pump is good. I replaced the fuel pump and two filters inside the fuel tank. Fresh fuel. Correct oil. Synthetic made for BPR. Never tried to rev it that high on the trailer. Not sure about that one.

 

[SabrToothSqrl]

A very, very brief blip of throttle should take it to 7k.

The logic being if it runs to 7k not under load, then the issue has to do with load and not electronics.

Just a thought.

Also I'm told the fuel pump on RFIs can be difficult....

But I'm more proficient with carb 951s

 

[jammin777]

were your injectors professionally cleaned and had spray pattern test? are raves opening when it reaches 4k to 4500 rpm? you can pull the rave caps off and lightly hold your hand on them, blip the throttle, you shold be able to feel the raves opening against your hand. just a few ideas for you to try.

 

[RDele]

were your injectors professionally cleaned and had spray pattern test? are raves opening when it reaches 4k to 4500 rpm? you can pull the rave caps off and lightly hold your hand on them, blip the throttle, you shold be able to feel the raves opening against your hand. just a few ideas for you to try.

Injectors were not professionally cleaned. I ran injector cleaner through them under 10 psi while pulsing them. Is that not good enough, you think?Could this be the problem?
I will check the raves but, I'm sure they are working fine.
Thanks for your help. I will keep you posted.

 

[jammin777]

i myself have had issues with my 99 gsx rfi, mainly very hard to no starting issues in the water. once running it runs great. ive rebuild , tested and replaced nearly everything except the coil! the rfi's are picky. but a totally different issue than yours. looks like you've covered a lot of basis. hopefully someone will chime in on your issue. in the mean time you can always download a service manual as it has procedures on ohm checking all the sensors.
as per manual clogged injectors, raves not opening, weak spark, low fuel pressure, exhaust restriction, water in fuel or stale fuel, incorrect tps sensor settings or bad?
also a possibility of incorrect rotary valve timing and or clearance all these can cause the symptoms you describe.

 

[RDele]

A very, very brief blip of throttle should take it to 7k.

The logic being if it runs to 7k not under load, then the issue has to do with load and not electronics.


Just a thought.

Also I'm told the fuel pump on RFIs can be difficult....

But I'm more proficient with carb 951s

I was finally able to give my ski some more attention. I did get the ski to reach the 7k mark but, it did some sputtering and not so smooth running to get there. Does this sound injector related? Can't do much more this season due to weather. Just trying to get my list of to do's ready for the spring.

Oh, as far as the fuel pump. I replaced it along with the two fuel filters.

 

[bkk42]

Did you ever figure out what was wrong? I'm having an issue with my GTX rfi where I'm only getting 4400 rpm.