1997 GSX 787 Wont Start in Water

[pthompson7]

I have a 1997 GSX with a 787 Rotax engine. I can get it to start fine out of the water, but once it put it in the water, it will turn over, but it just wont start. It acts like it wants to start, but it just wont start. Like its getting too much fuel and no air, or something. I can't figure it out. Does anyone have any ideas???

It would help a ton.

 

[LouDoo]

Hi,

Try increasing the idle, your ski should idle about 3000rpm on the trailer, and about 1500rpm in the water. Also try pulling the choke and giving a little throttle, you kinda need to pull the choke and hit the throttle with your arm.

If that doesn't work check the compression, should be about 150psi and no less than 135psi.

Lou

 

[Bills86e]

Its lean. Too much air, not enough fuel. OR old bad gas. Have you done your pre-seson maintenance? Take front basket out and look in your
removeable cup water separator/filter. Water & crap in there? pump oil changed? Are your carbs pop-off at 33psi? Might need those 40I internal filters cleaned. YUP!

Make your finale carburetor adjustments with your PWC in the water, with a full tank of gas. WHY?... If you make them with a 1/4 tank you will be running lean, have a lean condition when you are rideing wth a full tank of gas. If you make your low & high speed adjustments under load and a full tank of gas, you will always have gas in the carb(s).

 

[seadoodave1]

Hi,

Try increasing the idle, your ski should idle about 3000rpm on the trailer, and about 1500rpm in the water. Also try pulling the choke and giving a little throttle, you kinda need to pull the choke and hit the throttle with your arm.

If that doesn't work check the compression, should be about 150psi and no less than 135psi.

Lou..check out my thread on 94gtx compression..need some help!

Lou

Lou..check out my thread on 94gtx compression..need some help!

 

[LouDoo]

Lou..check out my thread on 94gtx compression..need some help!

O.K. Where is the thread?

Lou

 

[brandon32689]

check you water seperator oring first and make sure all the fuel clamps are tight and you dont have no air getting into the system, also check your compression and make sure it is all good, then go from there i would try the simple things first, maybe even clean your fuel selector.

 

[pthompson7]

I did change all of the fuel lines, last season, and removed the fuel selector switch. I tried to check the compression, but I can't even get it to crank over this season with the pluggs in. If I take them out, it cranks fine, but with the pluggs in it just doesn't run. Im at my wit's end with this thing. I'm thinking of selling it, Im getting tired of messing with it.

 

[Bills86e]

You may just have some oil in the lower case and didn't crank enough with the *plugs out to puke it. It may take 2 minutes, but just crank maybe 20 seconds, then take a minute break, repete & repete. Oil takes a little longer as its much thicker. Only use pre-mix to prime n start
a seadoo, after you get the oil out. Use a rag over the *plug holes during this easy proceedure to protect that nice garage ceiling. All seadoos will leak oil past the RV gear seals if they set along time. You may foul the plugs at the 1st start-up, so have a new set on-hand, and a great summer skiing.

 

[pthompson7]

Do you mean 2 or 22 minutes, I'm taking it as 2 minutes. 22 minutes seems like an unnatural time.

 

[Bills86e]

yes, 2-3 minutes between cranking to allow the starter to not overheat.

 

[pthompson7]

I was able to get it fired up in the garage, but now comes the daunting task of starting it in the water. That has always been the tough part with this thing since late last year. It just doesn't want to start in the water. Also ran a compression test, and there is 150 in both cylinders, (the front one was just a hair below 150, but it was pretty close, so I feel comfortable with the compression part of the engine. I'm thinking electrical or fuel delivery. I seem to always have a LOW 12 Volt error message, even with a fully charged, new battery, so there must be something draining the battery in this thing and I"m just not sure how to go about finding what is causing that either. Any ideas with that woudl be a huge help.

PS changed the rectifier last year to try and resolve the issue, no luck it didn't help that at all, unless I gotscammed and was sold a bad one.

Any ideas guys.

 

[Bills86e]

Back your ski tied to the trailor into the water to put load on the impellor when you start motor. Then you can use your tach to set idle speed and low speed adjuster. If you still have problem starting in water, either the pop-off is wrong or too much clearance in the rotary valve cavity, and the RV cover would need to be machined to bring the squish back to spec. Usually this is the case with hot motors.

Normally not starting when in load of water is not enough fuel in the mix, too much air.

If won't run, test the Rectifier, use your voltmeter and test at 5500 rpm's. if it is 15vdc or more, the Rectifier/regulator is bad. Metal shaveings, bits, particles in a Stator are a death knock
on a Rectifier's door!

Open grey box and Disconnect the red wire to the rectifier and see if it run great. restart the ski several times to confirm and if everything worked, Rec is bad, This is the Rectifier test. Rectifier go "slpiftzt" when you jump start a ski with a dead battery most of the time. This is a Simple mistake anyone can make.

Also usually if compression is bad, is cause of not starting in water, because all the fuel in the cylinder is NOT being ignited.

What usually is killing a battery in a Sea Doo with trim is water in the VTS unit. Pull the cover off and see if that's the case. If so, disconnect the harnesses coming out of the VTS module and see if your drain goes away.
The module can corrode the reed relays and make the vts not only inoperable, but can stick and continuosly be a drain on the chargeing & electrical system. So that said, disconnect the VTS harness, and see if the problem goes away!