04 Sportster Low Speed Low RPM... HELP!

[busterdoo]

This is my first post on the forum and my first boat (2004 Sportster LE).

I purchased the boat used from someone who told me the MPEM needed to be replaced but other than that the boat was great.

I got the boat and took it into the shop to have the computer changed and to find out, it was not the MPEM. They changed the spark plugs and a vac T connector and hoses. On land the boat would rev up great and sounded ok. Once on the water (this morning) the boat would not get over 4k RPMs and 10 MPH. The boat would not plane out at all, nor do much of anything else.

I took it back to the shop and the owner of the shop said that the impropler needed to be changed (something about the resistance of the water keeping the RPMs down) or some type of "gate" not opening. The shop tech said that the RAVE (I think) valves may need to be changed or adjusted.

I paid 5k for the boat and trailer and already 600 in repairs and the wife is already trying to get me to sell the thing and we have yet to get on the water together with it.

Any ideas and suggestions would be great!

Thanks from a very frustrated and poor first time boater!
Nick

 

[texasmojo]

Was your fan turned on when you got to the water?

 

[busterdoo]

I ran the blower for about 2 minutes while I was getting the boat ready for the water then I turned it off. Would that make a difference?

 

[kustomkarl]

Welcome to the seadoo forum Nick. The blower has nothing to do with it ...you should run the blower for 5 minutes before you start the boat or when you in a no wake zone, or you are below cruising speed. This keeps the gas fumes out of the engine compartment to prevent an explosion. If your mechanically inclined then maybe you should consider doing some repairs yourself. The RAVE,( Rotax Adjustable Variable Exhaust) valves can be easily removed and cleaned and replaced. The gate referred to is the reverse gate that allows the jet pump to reverse the thrust to go back words. I have an idea for you, if you want to tackle some service yourself, and save a ton of money. You could join as a "premium member". As a premium member you can down load a authentic seadoo manual from the seadoo manual library. In the library is a variety of manuals for almost all years and models. You can view as many as you like on line as a PDF file, or download it and print it for your personal and private use. There are operator manuals and repair manuals for you to do your own repairs on your seadoo. The repair manuals have everything from troubleshooting, repair procedures to winterizing. It contains wire diagrams torque specs and pictures for disassemble and assemble instructions. In the spec sheets it tells everything needed to maintain oil changes, spark plug gaps, carburetor rebuilds and impeller wear ring tolerances. Click on the "Seadoo Manuals" link at the top of the page for more details. If you need any help or get in a jam, we are always here to answer your questions too. Premium members get priority when it comes to getting quick detailed answers. It costs $10.95, for the month. It's a lot less than buying a paper manual like I did from my seadoo dealer for my boat that cost me $85.00.( the seadoo forum didn't have a manual for my new jet boat)

Let us know if you need any more help. We are here to help you get your seadoo running like it should...and save you money in the process.

Karl

 

[busterdoo]

Thanks for the quick response. I will give the shop until next Wed or Thursday to figure out what is wrong. If it is going to be too much or they cant figure it out, I will bring it home and start working on it myself.

Ill keep you updated.

Thanks
Nick

 

[busterdoo]

Finally heard from the dealership today and come to find out the throtle cable is broken. The BUDS system showed that at WOT I was only getting 60%. A new cable is on the way so hopefully I will be good to go. My only question is that why at 60% I cannot get on plane? Oh well, we will see if this is the fix.

 

[sanpan25]

The cable should help alot!

FYI: when you get it back, work the shifter forward and reverse. Look at the gate and how it moves, have someone help you. Understanding it is half the battle, the gate should lock in the forward position and the only way it can come out is from the shifter. If you can push the gate down while it is in forward your locking mechanism is not working.

 

[busterdoo]

Ok so I FINALLY got the boat back today and took it straight to the water. Well, first off let me say that according to the BUDS system I am now getting 100% throtle (on land) and they also replaced an exaust coupler hose that was cracked.

Ok onto the water now. I started it up, got out of the no wake zone, floored it and got to a measley 30 mph with the tac maxing out at 5000 flat. No matter what I did I couldnt get over 30 and 5k on the tac. The boat would take about 10-15 seconds to plain out. The engine ran extremely smooth with no hessitation or cavatation (if I understand what that means correctly).
Both RAVE valves (blue top as opposed to the red top) are screwed in even with the top and not all of the way down as some suggest. The gas is fresh and the tank is full of new oil...................HELP!

One last thing, the hull has been repaired and done so poorly if you ask me. There is no actual grate under the boat as whomever did the fiberglass job covered the mounting holes. I checked the shaft and everything is clean and free of debris. Could the poor fiberglass job be causing enough resistance in the water to keep it from reaching speed?

 

[busterdoo]

Update

I took the boat out today and noticed that I receive the same max RPM in neutral as I do in forward and reverse (5k). I called the guy that has been working on the boat and asked him if the rev limiter could be bad and he said he has never had to change the computer because of a rev limiter. Any ideas or suggestions before the wife makes me sell the thing and get a prop boat?

 

[kustomkarl]

That boat should max out at about 7300 rpm's. And should be closer to 55 at top speed. I bet the cable isn't correctly adjusted to give you full throttle. I would call the seadoo shop and explain the problem...I think it needs to be adjusted correctly to get full speed.

Karl

 

[busterdoo]

Is the cable something that I could adjust or something that a SeaDoo Tech sould mess with? I also noticed today when adjusting the RAVE valves on the water (which did absolutely nothing) that the Air Silencer had come off and was flapping around. I attached that and kept riding but it made no difference either.

If the throtle cable is something I could adjust myself, what am I looking to adjust on it and how much tension should I give. One other thing I thought of was that maybe the shifter was not fully locking into forward or reverse. I am going forward however could the boat think that the shifter is still in neutral and not allow 100% throtle? Im just throwing everything out to try to get the boat working and keep the wife from making me sell it. She gave me until Monday when she gets back in town to have it working or else!!!!!!!!!:boxing_smiley:

 

[seadoosnipe]

DI says it all.....

I know you don't want to want to hear this, but I'd have to side with your wife on this one.

Your engine is the 951 DI (direct injected) motor and is not rated as one of the most liked.

Trying to adjust the RAVE valves on this motor, is pretty much useless, since they are operated by the compressor of the direct injection system.

Although the throttle cable has a say in this, it's not rocket science to figure it out, since its only connected to twin, 46mm air induction throttle bodies. Remove the air box and flame arrestor you'll be able to see into the throttle bodies. With the boat in forward, push the throttle wide open. Now, look into the throttle bodies, the plates should be wide open. If one is and the other isn't, or both are equal but not all the way open, then this can effect the boats performance.

From listening to members complaints on this motor, the direct injection system of the 951 DI motors is like this. If you get one that works well. Then you'll have no problems from it. If you get one that's, well, like yours, then it'll be a problem for the time you own it.

The direct injection system has two components in the fuel system, timed with the #1 cylinder which is commanded by the mpem when to deliver itself to the cylinder for combustion.
First, the fuel injector is first told by the mpem to deliver a pre-determined amount of fuel to the direct injector. Second, the direct injector, under pressure from the compressor, pumps it into the cylinder at the right time for combustion.

This system is set up to deliver fuel in the high pressure side of the engines piston where as the RFI (Rotax fuel injected) is a low pressure injection system thats actually injected into the low pressure side of the cylinder at the end of the intake, inside the motor.

If the throttle body is o.k. and the engine is smooth, check to make sure the air lines going to the RAVE valves have air on them. The RAVE air lines have been known to block up or the solenoid may go out. This may also be a cause to the performance. A quick test on the solenid can be done, if you have another to drive the boat. While going as fast as the boat will take you, carefully remove the cap of one of the RAVE's. Then, have the driver slow the boat to a stop. Have your hand on the top of the RAVE, you should feel this valve open and close as the boat is coming to a stop. If not, then the solenoid is bad. You said you didn't notice any difference in the adjusments of the caps....that's because there are none on the DI motor.

It's 3:30 a.m. on Saturday, you got till Sunday night. You better get busy.

I wish you luck.............:cheers:

 

[busterdoo]

Holdin Out Hope!

I was looking at the boat today and noticed that the hose coming off of the RAVE valves (on into) is no going anywhere. There are two short hoses coming off of each valve with a T connector and another hose but it leads to nothing. Can anyone tell me where this goes???? I looked in a manual but couldnt really see where it went. Also, there is a 3rd RAVE valve on the motor with a silver cap over the adjustment screw. When I took the cover off the valve was very wet inside. I think this is part of the cooling system but not 100% sure.

HELP!

 

[robin savell lloyd]

I know it sounds crazy but look at the parts list under [air intake] and you should see where these rave valve hoses should go. good luck Robin :cheers:

 

[busterdoo]

Wavin the White Flag

So I am giving up on the ole boat. I connected the air hose to the RAVE Solonoid and discovered that one of the RAVE Valves didnt have a spring in it. A quick trip to the parts store and I have two new springs on the valves. Fired the thing up, NOTHING! Still only getting 5k on the tac. I did look at the switch in the control lever assy. and didnt know if that thing could be bad. Basically the switch is down when the boat is in Neutral and up with the boat is in forward or reverse. I dont know if it could be it or not.

Thanks for everyone that has tried to help on here... you have taught me a ton and it is truly appriciated.

If anyone is lying in bed and cant sleep and gets a wild idea of something that may be wrong, shoot me a line and let me know. I will check it out and see what we get.

Thanks again,
Nick

 

[robin savell lloyd]

Did you look at the parts as I tried to show you in my last post? It sounds like your rave valves may not be working as you say you have a hose that is not going any where on them. :cheers:

 

[robin savell lloyd]

I am not sure but thought this may have been for your rave valves but it may be for you compressor. I do not have the boat in front of me so I am not sure what I am looking at. http://partsfinder.onlinemicrofiche.com/seadooforums/Seadoo_oem/Seadoo_JB.asp?Type=13&A=97&B=7 :cheers: