Sea doo will run and start perfect on trailer but not on water!

[elivazquez]

Have a 1994 sea doo gts, it will start perfect on a trailer for when I put it on the water it will just turn I check the compression and is reading 122. I heard that maybe it could be the oil & gas ratio but I do not know what that means. it has separate tanks for oil and gas. spark plugs are brand new and g k and the card has been cleaned. what else could I check

 

[slag]

Re: Sea doo will run and start perfect on trailer but not on water!

It could be a ton of things. The clearance between the rotary valve and cover might be out of whack. Easy to start with no load, put it in the water and much harder. Could be electrical that the process below could solve:
Remove the spark plug boot, clip the wires back 1/4 of an inch, reattach the boot (usually it screws into the end of the wire), and put it back on the spark plug. do this only if you have enough slack in the wire.
Could be a plugged fuel selector. On older jetskis, the gray fuel line ALWAYS deteriorates and necessitates replacing all 20 some feet of fuel line. The interior turns to green jelly and plugs the various orifices, fuel selector area, etc. Hard to tell exactly what is wrong.

 

[frozenokie]

Re: Sea doo will run and start perfect on trailer but not on water!

What is your RPM reading while on the trailer?

 

[elivazquez]

Re: Sea doo will run and start perfect on trailer but not on water!

How could I find out? Dont have a RPM reader on handles or dash.

 

[frozenokie]

Re: Sea doo will run and start perfect on trailer but not on water!

You'll have to get the Tach tester from a dealer to hook it up. Or maybe someone else may know of a substitute or different way to tell.

This is what I would do in your case and if I didn't have a tachometer:

While on the trailer, does the sound of it idleing sound "normal" meaning like a motorcycle would idle or lawnmower, or similar 2 cycle motor? You probably know that there should be a nice - soft purr to the idle. Now then - what you are looking for is the sound like it's set on way too high of an idle setting. Almost like sitting at a red light and revving up the motor before popping the clutch. I think you get the idea, right? Reason is once you put it in the water, the water puts enough pressure on the impeller to bring the idle way down. If your motor sound like it's just "purring" nicely, then it's set too low.

Go ahead and find the idle setting screw that physically opens/shuts the butterfly plates when turned - that's the correct idle setting screw and it should be one screw for both carbs usually facing more upward, or at an odd angle, than any others. On my GTX, it is on the front side of the front carb and sits at a 45 deg angle - on my waverunner it is on the back face of the back carb right out in the open and faces upward. The ones I have also have a little "T" bar through then so you can turn them with your fingers.

Now after you find the right idle screw - take it to the water and wade it to at least knee deep water - best to have a friend to help hold it still so it doesnt get away from you if it starts - and try to start it. If it doesn't, turn that screw clockwise in 1/4 turn increments until it starts. I wouldn't turn the screw any more than a total of two complete revolutions (or 2 180 deg. turns in). Each turn of the screw, if you have the air intake cover off, you can see the butterfly start to move when you're close to the right setting. If it doesn't start, then there is probably something else going on.

Otherwise - you need a dealer to hook up the tach reader or find someone that has one to borrow.

 

[crownlover]

Re: Sea doo will run and start perfect on trailer but not on water!

I have a 92 that does the same thing. starts good on tailor and runs great until you put water in it and still runs good until you shut it off. Try to start it up again and nothing. Pull it out of the water and she fires right up

 

[NESAR]

Re: Sea doo will run and start perfect on trailer but not on water!

Try to pump grease into the drive shaft 2 pumps will do it may be as simple as that.

 

[scooper77515]

Re: Sea doo will run and start perfect on trailer but not on water!

frozenokie was getting at the point that the idle will be about half in the water compared to out of the water.

So, if you want it to idle at 1500 in the water, it will need to idle at 3000 out of the water.

If you have it at a nice 1500 idle on the trailer, then when you put it in the water, it will idle at 750 and most likely not stay running.

 

[Leedanger]

Re: Sea doo will run and start perfect on trailer but not on water!

frozenokie was getting at the point that the idle will be about half in the water compared to out of the water.

So, if you want it to idle at 1500 in the water, it will need to idle at 3000 out of the water.

If you have it at a nice 1500 idle on the trailer, then when you put it in the water, it will idle at 750 and most likely not stay running.

Sorry to hijack but personally when I have the idle set upwards of about 1400 in the water, I am hauling *** in the no wake zone....Is this normal? It's been allot of years since I've driven a well tuned machine so I am honestly not to sure about how it's supposed to behave when it's actually using it's manners. It's fast enough I have to push and pull it in and out of neutral--->forward in order to not be "that guy" in the no wake zone.

 

[scooper77515]

Re: Sea doo will run and start perfect on trailer but not on water!

It really depends on the model. Mine idled fine at 3000 on land, 1500 on water, and was very slow until I hit the gas.

I have almost ALL the seadoo manuals, let me know what model and engine size you have, I can look it up for you.

 

[Leedanger]

Re: Sea doo will run and start perfect on trailer but not on water!

It really depends on the model. Mine idled fine at 3000 on land, 1500 on water, and was very slow until I hit the gas.

I have almost ALL the seadoo manuals, let me know what model and engine size you have, I can look it up for you.

98 and 99 both are SeaDoo GTX Limiteds. 951cc

 

[scooper77515]

Re: Sea doo will run and start perfect on trailer but not on water!

According to the Seadoo manuals...Leedanger, your 98 GTX is 1500 in water, 3000 out of water.

Original poster's 94 GTS comes with two different engines, both idle at 1400 in water. If 587 ci engine, it will be 2500 out of water. If 657 engine, dry idle to 2800.

Yes, that is counterintuitive...you would think the bigger engine would stall out less when put in the water and dry idle would be lower.

 

[Bear Claw]

I have spent several long days/nights and hours searching for the possible solution to the same problem. My Ski would run fine out of the water and sitting on the trailer but as soon as I launched the ski into the water it would not start up again. It was as if something choking it down or as if was starving for fuel. Well I have a twin pair of 2000 Seadoo GTX RFI Skis and was able to troubleshoot the issue myself. What I found was the REVERSE GATE was way out of adjustment. I bought the skis used and of course inherated the problem. The gate was covering way too much of the jet exhaust opening causing the pressure to return back into the jet, leaving the exhaust with no exit. After adjusting the reverse gate both skis now will run at or about 60MPH and both start and run fine in the water and on the trailer. I sure hope this helps the many people out there that has been looking for a solution to the same problem. Search after search I found that many people had the same issue and had, like me spent a bit of money guessing what the issue might be.. It was a simple adjustment!! Good luck with yours!!! I'm sure it won't be your R.A.V.E valve, Fuel pump, Fuel pressure regulator, Rectifier act.....Several people have adjusted these gates hoping to gain more speed with their ski and this was just one of many issues that was caused by doing so. Anyway, hope the best for you all.
Bear Claw

 

[GA_Boater]

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