Challenger 97 110HP max RPM 4200

[Nisdj]

Hi Forum, hope someone can help me with my Seedoo problem.

For 6 month ago I bought a Challenger from 1997 with a single 110HP Rotax (787). The last two month I have spend in and out of water trying to solve a motor problem. The problem is that the motor (with the boat In water) only retch about 4200RPM -it does it slow and not quick an agile like it supposed to.

Here is the story:
First time in water the motor accelerate to 7000RPM as it should, unfortunately it suffered from strong cavitation and I had to change the wear ring, this was done without problems. At same time I changed the battery, unfortunately I wired it wrong (stupid mistake –I know). The result was a burned fuse but the engine had no start problem.

Second time in water, a little start problems and the RPM problem showed up for the first time. Max RPM was 4200 and I constant had the feeling “how long do I get”. Engine stopped after running about 10min, and I was towed back!!!
Home again I cleaned the carbs and changed the diagrams.

Third time in water, much easier start -slow out to get a little heat in the engine and accelerated to about 7000RPM for about 10sec, then it went down to the 4200RPM. Sailing (slow) in 10min. –this time I got home by myself.

All tubes are black and there was no sign of sludge in the carbs. I took of the black cap at the RAVE´s, they move easily but are there any things else to control ? I also checked the acceleration pump, and it works fine.


Is it:
-The MPEM is crashed because of the wrong wireing. (How to check?)
-The switcs under the F N R panel is broken, and activates the REW limiter. (but isn’t it 3500RPM?)
-Could it be the rectifier. (How to check?)


Or is it something else. Please help –I suffer…………………

Best regards from Denmark

 

[seadooya]

rectifier test, on trailer hold idle around 5500, or as close to it, voltest battery, should be high 13's...

Even though the raves move freely, doesnt mean they're moving at its fullest. Remove from engine, and clean

With wiring battery wrong, could've done damage to mpem, and/or the stator assy. Seen smoke come from there, with battery hooked wrong.

 

[Nisdj]

Challenger 97 110Hp RPM 4200

Hi there

I have now dismantled and cleaned the RAVES and found no failure there. I also made a compression test 135psi and 140psi and I assume that it also is fine. Then I checked the switch under the power console, it was OK. I made a visually inspection of the electrical components to see if they had been hot, and I also have not seen any smoke.
Then I mounted two new sparks and tried to start the bastard -without any success. Not even injection of ether gave any result!!! The spark plug were wet of gasoline and there is a fine spark, I also dismantled the flame arrester and here I saw something strange, atomized gasoline was shot backwards and out in the engine room.
Since the engine did not run, I had no chance to check the rectifier.

Please advise me what to do next.............