2002 GTX DI won’t rev in water, my mechanic is stumped.

[JCT]

Still having trouble with my 2002 DI.
Everything started after sinking one fall.
‘Got as much water out of engine as possible by removing plugs and turning engine over.
Didn’t know at the time to unhook air pump...
then Ran engine a few minutes on trailer with hose.
Next spring it ran great on trailer.
Won’t accelerate in water.

Mechanic has had it for 3 months-
fixed/replaced stuck ring.
Resleeved air pump.
Verified fuel and air pressure
Verified good compression
Now he thinks it may be bad mpem.

I brought ski home from shop for the winter.
Took out mpem and plan to send in for testing.
Bought new voltage rectifier (just in case)

from reading here I think I need to ask my mechanic if he checked the reed valves.

Does anyone have any suggestions from here?
Do you think the mpem or voltage regulator/rectifier could cause this problem?

 

[Whus02]

It sounds like it could be a rectifier. Can you elaborate on the issue? Does the engine run at all in the water? When you try to accelerate, does the engine rev up without the ski going anywhere? Or does the engine vibrate a lot without going anywhere?

 

[JCT]

Thank you for replying
Yes runs in water, accelerates a little ,no more than 10mph, will not plane.
No vibration.

 

[etemplet]

Check the battery voltage.

 

[JCT]

Put in new battery this spring.

 

[etemplet]

Did you remove the ECU and open it up? I found my 2001 GTI with water and corrosion in there. I cleaned it up, dried it out and it worked dang near perfect.

 

[JCT]

What is a ECU?
The mpem?
How do you open it to clean?

 

[etemplet]

Sorry this is all I got on the box. It's up front on the left hand side of the ski. This particular ski, when I installed the battery, would not turn the engine over. It just said, LOW VOLATGE and 4 long beeps. When I was checking the front electrical connections I noticed a bit of moisture so I elected to remove the box and open it up. After cleaning and drying it... the ski started right up and ran pretty darn good.

 

[JCT]

Looked it up, my 2002 has a mpem not a ecu afaik.
Can’t open a mpem-

 

[etemplet]

Sorry.... that's a picture of an RFI. Good Luck.

 

[ski-d00]

Broken reed valves happen when the motor gets water in it and then it is cranked. After water is removed, the result is starts, idles, runs fine on trailer but won't rev past 3000 rpms or so in water and won't make power. The DI motor is exceptionally prone to this problem. Sound familiar?

 

[JCT]

Thought I would post an update.
After I replaced the rectifier there was no change.
I then got brave and removed the throttle bodies to check the reed valves.
Viola! One reed had two missing petals and another a cracked petal.
I talked to the mechanic who said he checked the reeds with a scope from the top when he was replacing a piston...
I will be trying again next weekend and will post the result.
THANK YOU so much for all the help!!!

 

[POPPS]

Broken reed valves happen when the motor gets water in it and then it is cranked. After water is removed, the result is starts, idles, runs fine on trailer but won't rev past 3000 rpms or so in water and won't make power. The DI motor is exceptionally prone to this problem,,,
Great call SD.

 

[nickmo12]

Thanks for the update. Too many times folks here are given great advice from people who know what they're talking about and they never post the result.

 

[JCT]

Took it out last weekend.
Initially got about 30 mph changed plugs with ultrasonically cleaned and newly gapped plugs (1.0 mm didn’t have 1.1 mm gapper or new plug) now 6540 rpm and 40 mph indicated.
Is it ok to ride like that? I assume it should be faster.
I am not interested in blasting speed but I do want it run properly/safely.
I will try to clean the rave valves.
Anything else?

 

[j.harris]

How is the condition of your jet pump? Sounds like the engine RPM is getting high enough but the speed isn't there.

 

[jimmyluke]

Took it out last weekend.
Initially got about 30 mph changed plugs with ultrasonically cleaned and newly gapped plugs (1.0 mm didn’t have 1.1 mm gapper or new plug) now 6540 rpm and 40 mph indicated.
Is it ok to ride like that? I assume it should be faster.
I am not interested in blasting speed but I do want it run properly/safely.
I will try to clean the rave valves.
Anything else?

One of my skis is a 2002GTXDI like yours and I also only get about 6540-6600RPMs. I know I should be getting a couple hundred more but I’m just not so worried about it anymore. I also used to only get 40 mph on the speedometer and that’s all I would get time after time. I eventually raised the OPAS steering paddles and also changed my carbon seal assembly and boom 50 mph! I did not ever take the time to figure out which one of the two changes picked up the 10 mph. Maybe it was a combination of both of them? Someday I’ll try to get a couple hundred extra RPM out but not right now. Keep us posted we all like to know these things.[emoji1]

 

[JCT]

I removed my OPAS since that was the original cause of my flooding. I park on an old jet port which ripped off the paddles and tore the interior tubing.
I will post after I clean the raves.

 

[jimmyluke]

I removed my OPAS since that was the original cause of my flooding. I park on an old jet port which ripped off the paddles and tore the interior tubing.
I will post after I clean the raves.

That’s good that you’re going to clean the raves and hopefully you’ll pick up some RPMs. But the point that I was getting at is that even at your current RPMs you should be getting at least 10 mph faster.

 

[POPPS]

Leaking carbon ring will do it, opas not coming out of the water will do it (racers remove them), sticking rav's will also contribute,,rarely on a ski...its not just one thing,,,but things lurking and helping out,,,did you check the wear ring clearance?

 

[IamRobco]

ski-d00 great call. 430 hp. on your challenger, is that normal or tricked out ?. Thing must fly ya.