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1998 speedster 3500-4500rpm NEED HELP!!

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98seadoospeedster

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hello
I don't even know where to begin but i will try. I recently purchased a 1998 speedster (my first ever watercraft of any kind) from a guy who got it from the original owner. I knew from the beginning that the boat would need some work and since i'm pretty mechanically inclined, i thought i could get the boat working on my own. sadly this is not the case, i've already spent >30 hrs on this forum doing research, 3.5 weeks working on the boat and a shameful amount of money $$ but this boat has so many problems that now Im begging for any assistance!

when i first looked at the boat, the previous owner started both engines one at a time. both engines started and stalled within a few seconds. (he said it was cold) because i didn't know any better, i believed him. i asked if we could take it out on the water but it was already 8:30pm and he said that the wear rings were so badly worn out that we wouldn't really go anywhere. I ended up buying the boat thinking that the only thing wrong with it was the "wear rings".

I brought the boat home and i couldn't sleep because of the excitement. i read through the original owners manual front to back. with the intention of taking it out on the river the next day.even though i was told that it needed wear rings, i wanted to test the engines on the water......... and so the journey begins.........

when i placed the key on the dess port, i heard NO BEEPS! pulled the choke and pushed the start button on starbord engine and it started right away! did the same thing for the port engine and it cranked but did not start! we tried starting it for a good 30 minutes and eventually gave up and hauled it back home.

*things i learned about my boat after the first launch*
1. something was wrong with the beeper
2. fuel guage does not work
3. speedometer does not work
4. tach on running engine does not work
5. i did not have a stern light
6. storage locker under the deck was disgustingly dirty

the next day, i remember spending at least 4 hours on here trying to figure out why the engine would not start. after reading a bunch of threads, i rented a compression tester at autozone and bought a set of 4 BR8ES NGK plugs. i pulled the old plugs and ran a compression test for the engine that wouldnt start. mag 138=psi pto=140psi. I gapped the plugs and installed them right away. i took the rave valves apart and cleaned them (they weren't too dirty) when i tried to start it, the engine started but stall right away. i got it to run by pushing the trottle a bit. It sounded terrible. like it wanted to stall. i stopped the engine and quickly came back here to see what was next.

after more research i decided to try and rebuild the carbs on the troubled engine. I LOOKED EVERYWHERE but could not find a carb kit specifically for my boat (devorced fuel pump) i found a kit on amazon for about $85 bucks with a description that said "genuine mikuni". I also bought 2 OEM wear rings and neoprene seals. i also bought a buzzer assembly from floyd bell

while waiting for my parts to arrive i decided to clean my boat. it had been sitting under a tree and there were leaves everywhere. I bought a new microfiber sponge and washed the entire boat (inside and out) with dawn dish soap and water. the dawn dish soap really did a good job in removing tough stains that i thought would never come off. cleaning the seats were a bitch because the foam was dirty so every time it got wet and compressed, it would ooze dirty water where i had already cleaned.

*things i learned about my boat after washing it*
1. the storage locker under the deck DOES NOT DRAIN!
i had to manually remove the dirty water via cup and bucket.
i tried spraying a "jet" stream from my hose into the hole towards the back of the storage locker but
that didnt work
2. my boat has red "bottom paint" below the water line.
3. automotive polish does not remove oxidation
4. my boat was surprisingly clean (no cracks in gel coat) for being a 98.

when the parts arrived, i decided to tackle the carb rebuild first. although the description on amazon said "genuine mikuni", it did not come in mikuni packaging. i bought a couple cans of carb cleaner, got some clean rags and went to work. removed the carbs from the engine and cleaned them to the best of my ability using the carb cleaner, hard plastic brush and soft metal brush. every screw was a fight to remove. i removed the ls adjustment, hs adjustment ls jet, hs jet, needle and seat assembly and cleaned them thoroughly on both carbs. the carb kit i bought came with a bunch of other parts that i did not see a use for. i did not change the needle and seat assembly i only replaced rubber o-rings, the internal fuel filter and all the gaskets. after about 4-5 hours, i got both carbs assembled, adjusted the LS to 1 1/4 turns out and the HS to 0 turns. with the carbs back on the boat, i was anxious to see if my hard work had paid off.

before staring the engine, i installed the new beeper assembly, siphoned all the old gas from the tank and cleaned out the inline fuel filters. i replaced the wear rings (which were totally destroyed) and changed the pump oil (which was black! like REAL black and smelled just terrible) i reinstalled the jet pumps after a fresh coat of paint and put in about 20 gallons of 87 octain gas. i hooked up the hose to the troubled engine and tried to start it. IT STARTS RIGHT AWAY and idles at 1000 rpm. still sounded rough. after reading that it should be idling at 3k rpm on land, i adjusted the idle screw.

now both engines are running and idling so i went back to the river. once i got on the water, put the lanyard on (2 beeps) and i started the engines. rpm on the troubled engine was around 1000-1500. i slowly idled away from the dock. everything was looking good. as soon as i got out of the no wake zone i opened the throttle and BOTH ENGINES DIED!! i quickly tried to start the engines. both engines cranked but did not start right away. after about 3-4 minutes i got both engines to start by pulling the choke and slightly pushing the throttle (less than 1/8 of WOP). by this time, the tach that WAS working wasn't working anymore. and we had drifted far away from the dock (strong current). I tried to open the throttle above idle speed but everytime i did, both engines wanted to stall. my brother suggested that i try opening the throttle while pulling the choke so i did that and the engines reved up and stayed running. it felt really smooth. all of a sudden, the tach that stopped working earlier started working again and it read 3500rpm.

i noticed that i was able to start the engines while in forward gear, i found out that that was a sign of a bad neutral switch. i tore the lever assembly apart and found the switch to be heavily gummed up i sprayed it down with electrical parts cleaner and lubed it with di-electric grease and now it does what its supposed to. if i try to start any engine in F or reverse, it will BEEP and wont crank.

i took the boat out again after cleaning the neutral switch and its making a little progress. I still have to pull the choke while opening the throttle in order to keep the engines from stalling. now the troubled engine (port side) will rev between 3500-4500 rpm. good running (starbord side) engine tach does not work still. i switched the wires on both tachs and the good engine will rev up to 6800 rpm.

i have more details but i have to go. any suggestions or assistance is greatly appreciated i know it was a long read but thanks in advance!!!!
 
Don't run it anymore.... you can burn up a piston if your runni g lean. Have a professional look at the carbs.
 
Thanks for the quick reply. I have some updates. I took the spark plugs out to inspect them and 3 out of the 4 spark plugs looked like they fouled out. The last plug looked BRAND NEW! like it wasnt firing AT ALL. all of the plugs were wet with gasoline. Ill try and upload a picture
 
Just an update for anyone who cares.

The hesitation problem when opening the throttle was due to a fauly check valve in the accelerator pump.

Ive changed the rectifier on both engines and installed an aftermarket mikuni high flow dual outlet feul pump. I mounted it in the same place where the old fuel pump was (just drilled and tapped new holes)

Starbord engine works like a dream port engine seems to only want to go to either 3500rpm or 4500 rpm but only after the boat has picked up speed. If i decrease the throttle at all it goes back down to 3500

I inspected the rave valves on the port (bad) engine and the threads on the plastic cap where the guillotine screws into has melted and no longer holds onto the guillotine... In other words even if the bellows were working properly, the valve itself was not lifting.

I found a seadoo mechanic who claimed to have rave valves for my engine so i bought them from him for 40/peice. These guillotine valves were the wrong ****ing ones. They were about a half an inch longer than my original ones.
 
I just want to fix this boat so i can enjoy the water. I know some of you guys feel my pain. Is there no one here willin to help? Atleast point me in the right direction of how i can get my port engine to rev like its supposed to. There is compression there is spark (ive tested both) there is fuel ( my plugs are wet with gasoline and the engine runs)

...im begging here
 
You get the new bellows yet? Also, inspect the water regulator that's c mounted on the muffler. A clear indication of a faulty one IS 3500/4500 rpms...
 
Pop the call off and inspect. Can remove entire assy from muffler by disconnect the lines and twisting the unit off
 
My 97 challenger is exhibiting the same symptoms. I found fuel leaks on both motors pulse lines. I undetstand that this will cause poor RPM (3500-4000) in the water. Can't prove it out in the water until Wednesday. I'll update my situation then. Good luck!
 
Check to see if the Welch plugs are leaking from the tuned pipe. One of mine was leaking pretty bad one day and engine was running pretty bad.
 
One more thing... did the rubber diaphragm have a red nipple? I'm a little skeptical about the carbs kits. Genuine mikuni comes in original packaging. Did you do a pop off test before and after diaphragm cover was installed?
 
Sorry to hear about all the troubles. I'm trying to sort out my 98 Speedster myself and at every turn I'm finding problem after problem.

In regards to your ski locker not draining, I found that it does drain but the drain hole is probably plugged with a bunch of trash. I had to use a stiff material (in my case a broken tape measure) and feed it through the locker drain hole and force all the crap out of it. Between doing that and blasting it with a pressure washer, it finally came clear and drains. I'd check that out and see if that's your culprit.

I'll be following this closely and provide you input if I experience the same conditions when I get my port engine sorted.
 
Sorry for the late replies. After much time and much more money, i was finally able to get both engines to run at around 7k rpm! In one fell swoop, i fixed the leaking exhaust (new exhaust manifold and tuned pipe gaskets on both engines) replaced the rectifiers (both of them) replaced the raves (one out of 4 was the old style non slotted) replaced both fuel pumps with new dual outlet mikuni pumps (each carb has its own fuel inlet) and i was able to figure out how to unclog the drain for the flor storage locker. im still having some throttle issues. Port side engine (the one i was having trouble with) will rev out really high at half throttle. Maybe a carb adjustment issue? Maybe needle gets stuck open? I also messed around with the accelerator pump to unclog the ball and spring check valve thats inside. Overall probobly running at about 85% which i think might be good enough for the season. I can go about 45 mph TOP SPEED
 
You should be seeing about 55mph in that boat. If you can reach 7k Rpms you may be experiencing some cavitation issues.
 
There is definately some cavitation. I replaced the wear rings with brand new oem wear rings and i even put the neopreme seals on them. Cavitation is most evident when ripping it from idle. It will rev high for a second or two before it actually accelerates. Its wierd because the port engine will rev high then drop to about 6500 as the boat starts to actually accelerate.
 
It's hard to tell since I have to always have the trunk on enclosed when I'm running the boat in the water. I'm thinking about just replacing the carbon ring on both engines as a tester but those parts can get pretty expensive. Is there a way to tell if the carbon ring or Bellows need to be replaced without putting it in the water?
 
You can put a big ziptie back behind the bellows to put more tension against stainless hat/carbon ring
 
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