High rpm and engine noise

[lakelifeseadoo]

Im new the seadoo boats and jet skis. I bought a 96 Seadoo sportster about a month ago, took it the lake once and it ran like a champ. Took it back out the following weekend and it broke down on me in the middle of the lake. The boat wouldnt start, pulled the cover off the electrical box and noticed a nut was missing from the coil that apparently was grounding it out. got it home and replaced it, started up fine, now when it idles just fine, but as soon as throttle is given to it it starts to rev really high and shortly after an awful noise starts. let off the throttle and it idles fine again. the guy who had the boat before me let it sit for almost a year without even a crank so i was thinking it might possibly be the carbs not letting oil pass thru and only letting gasoline. Any ideas??? very frustrated that i just bought it and cant seem to figure out what the problem is. like i said though, im new to jet boats and inboard motors period. ive been reading thru some of the other threads and have seen similiar problems but i havent seen anyone with high revving and also the screeching noise. Any help is greatly appreciated! THANKS!

 

[Dr Honda]

Are you reving it up out of the water?? If you are... that's very bad. You need to put a load on the engine.

If you think that you aren't getting oil... then you need to either put some oil in the gas, and go pre-mix... or figure out if the injection pump is pumping. The carbs don't have anything to do with the oil. On a seadoo injection system, it is going into the manifold, below the carbs, but the nozzles could be plugged up.

 

[lakelifeseadoo]

Thanks for the help Dr honda, I was revving it out of water. It started doing it at the lake and i realized after i trailered it that the coil wasnt grounded so then i began to examine it on the water with just the water running to it. Could this be causing the screeching noise? and high rpms? Thanks

 

[seadooya]

your 'screeching" noise, is the lateral play on the impellor/pump assy. Its normal. Once submerged or off idle, it'll go away.

 

[Dr Honda]

your 'screeching" noise, is the lateral play on the impellor/pump assy. Its normal. Once submerged or off idle, it'll go away.

Yep... what he said.

 

[lakelifeseadoo]

Thanks for the replies! I took it to a mechanic today and he said that the carbs were clogged to no end and that he think the screeching noise to be a bearing going out in the shaft, I'm assuming he meant the thrust bearing in the jet pump, sound legitimate? Says he will clean up the carbs for 120 dollars and he will have to see what all replacing the bearings will entail. What do you think?

 

[seadooya]

Go get your ski, bud. Theres more than enough "talent" on this forum, to help/walk you thru, cleaning the carbs. Isnt this why your here? for help. To each there own, but i'd say, try to remove/clean/re-install the carbs yourself...self gratification...:cheers:

 

[lakelifeseadoo]

Thanks for the help! but it revving high sound like bc of the bearing going out in the pump? like maybe its not getting back pressure or somethin? and i may clean the carbs myself but replacing the bearing in the pump is a completely different world to me haha

 

[hotrod6927]

I just stumbled upon your thread. I had similar symptoms in my 97 challenger 1800. Anyway long story short the rectifier was the culprit for the fluctuating RPMs. SO if the carb rebuild does not do the trick then test the rectifier. It is located in the electrical box it has 2 yellow and 1 red wires that go to it. You can either disconect the wires and run it on the water and see if the reving symptoms go away or you can test it with a volt meter. if you do the volt meter what you do is in the water bring the boat up to 5500 rpms and then test the voltage on the battery it should be betwen 13.5 and 14.5 volts, I think, ill double check that range. Anyway if it is too high or low than the rectifier is bad and needs to be replaced. You can get an aftermarket for $50 and it is super easy to install yourself. 10 min job. Anway hope this helps. I personally did both tests but think that the pull the rectifier off test is the easiest way to do it. Just dont run it too long with it off or you will kill the battery.