1998 Seadoo Challenger 1800 engine question help me please!

[koontek]

Hey Guys,
So here is the story behind my 1998 Seadoo Challenger 1800. I found a guy that had it posted on craigslist about 2 months ago. We met up for a test drive on lake Washington. At that point both motors work but he stated the drivers side motor was just rebuilt by him and sometimes acts up. The things he mention was it will die if idle too long, takes 2-3 seconds after hitting the throttle before it revs up, also will sometimes cut out but starts right up. Well being my first boat and the price he was asking i didn't really think much of it. After 15 min's of driving around the driver motor cut out and turned off. This time it didn't start up. At that point we both realize the driver side motor that was just rebuilt had some major problems. 2 hours later I had a new boat for half of his asking price!

Moving on I had a seadoo mechanic rebuild the motor for me with wisco pistons. When he took the motor apart the piston was melted he thinks due to some type of lean condition?

Okay so today was day 1 for the new motor break in. Took it out was really easy on the throttle never did and wide open runs. After about 20 mins the driver side motor cut out but started right up. Now i go to throttle it and its slow at reacting. Then it cuts out 5 mins later again but starts right up. SO basically where im getting at is its doing the same symptoms right before the motor failed last time before i rebuilt it. at this point i head back for shore and put the boat back on the trailer.

I have no idea what is wrong that driver side motor! I do not want to bring back out until we find out why its acting up. Being my first boat i was wondering if anybody else on this board has had these problems before? carb settings? ecu problms? sorry guys I'm such a newb at 2 stroke motors mostly in boats! Any ideas or tips in the right direction would help guys! thanks!

 

[parrothd]

Take it back to the "seadoo" mechanic..

Did this guy rebuild the carbs/clean the fuel system?

If he knew the previous engine was ruined by a lean condition and he rebuilt the engine without fixing the original issue that new motor is toast. I'd take it back and get your money back and find someone that knows 2 cycle engines..

Any lean condition on 2 cycle motors is bad and will destroy a motor in seconds...

 

[kustomkarl]

What the mechanic should have done is find, and resolve the problem that caused the failure in the first place. Rebuilding a engine after a failure is good , but you shouldn't just rebuild it and figure the problem went away. Was it oil starved? Was it a cooling problem causing it to over heat and seize? Were the carbs adjusted properly? These issues should have been looked at, and resolved before you spent money on rebuilding a broken engine. Have the seadoo tech that rebuilt it check it out before you seize it again. It should still be warranted.



Karl

 

[PWCdoc]

I agree with Karl. Also, I recommend using either OEM or PRO-X pistons in a recreational powerplant. Wiseco pistons expand differently than the others (forged vs. cast pistons) and expand/contract at different rates.

 

[koontek]

Thanks for all the input guys. well here is the update. The mechanic has no idea why the engine is doing what it is doing. We took it out and it ran great for about the first 5 mins. after that the engine cuts out and will not go past 4500-5000 rpm then once you let off it idles and when you hit the throttle again it dies. We pulled the spark plugs and while on the water and it looks like cylinder 1 is running good while cylinder 2 is too rich? At this point i do not know what to do. Where i'm located there is only 1 seadoo dealership and they are about 3 weeks back out just to take a look at it. Once they take a look it and decided what the problem it is they put it back in line for another couple weeks to get fix. Did i mention they are very expensive! Does this sound like a carb issue or electrical issuse to you guys? I was consdering downloading the service manual and trying to rebuild the carbs my self but this is my first water craft and i'm a little nervious. Feels like i will never get my boat running 100% at this point : (

 

[PWCdoc]

Sounds like a carb issue to me. You don't need a dealership. Find a local reputable independant shop to take a look at it.

 

[koontek]

Got some really bad news today about my challenger boat. I found a independent seadoo mechanic that knew his stuff. He look over the motor did some basic test and then went for a drive on the water. He concluded that my oil injection system is not working properly and it is starving cylinder number 2. That is why when it warms up it shuts down. The cylinder is basically seizing up. Also the piston is slapping the rave valve probably due to a bad crank. At this point I'm not sure if its worth it to fix the boat. Its going to need a new block, oil injection system, and whatever parts i should replace while its all apart. My first seadoo boat experience is not going so well guys

 

[PWCdoc]

Well, that may be possible but the crank's condition will have no bearing on whether it hits the RAVE valve or not. The factor that dictates piston/valve contact is clearance. The crank can be toast and it will not cause the piston to hit it. Also, it is rare that the oil injection craps out. Usually it is just the small supply lines that get old and crack keeping the oil from reaching the crank and cylinders.

My experience with the Doos is that the #2 cylinder will almost always be the one that seizes first. This is primarily due to the design of the carb setup with the front carb having the only fuel pump. Once the pump begins to lose it's efficiency, the #2 cylinder pays the price.

He may know a lot about Doos but you might want to have another shop check it out.