GTX wont idle or start in water runs rich

[toolguy]

Have a 96 GTX 800 that runs rich,(wet plugs) wont idle and wont start in water.
Does run on the trailer if the throttle is held.
Mechanic (who is well respected in my area) checked compression, 150 per side, rebuilt carbs, checked rotary timing,drained gas and filter, reassembled and ran motor.
Still same problem,
swaped carbs form a good running boat still no luck. runs exactly the same
He is now leaning toward MEM not changing spark curve. Does this sound logical for symptoms above?
Where would I look assuming carbs are good.

[WATERCRAFTSERVICES]

Re: GTX wont idle or start in water runs rich

When You Say Wet Plugs Are They Fuel Wet Or Oil Wet. Your Inner Crank Seal May Be Bad And Allowing Rotary Gear Bath Oil To Enter The Combustion Chamber Causing This Problem. Other Wise If You Are 100% Sure The Carbs Are Good Double Check All The Lines And Make Sure They Are Installed Correctly.

[vwjohn]

Re: GTX wont idle or start in water runs rich

Mine is doing the same EXACT thing!! If you recall from my thread about me having problems with my new engine. 96 GTX new 787 motor the plugs are wet and it won't start unless I hold throttle pinned and then it sputters until it cleans out. It runs fine on the trailer but you can smell the gas and the plugs are wet with gas when I pull them after idling for a short time. You suggested that the motor might have seized on me. I checked the compression and it is 150 on both cylinders. It runs smooth once you get it off idle. I started taking the low speed screws in and got them to 3/4 but it still seems like it is dumping fuel. This is too wierd 2 motors doing the same thing! BTW i am on premix now
John

[mad mike]

Re: GTX wont idle or start in water runs rich

check the clearence between rotery valve cover and crankcase the clearence must be now more than 0.25 mm / 0.0098 inch if the clearence is more that could be the problem I have had some skis for engine rebuild that had the same problem runs good on the trailer and in the water the ski wont start.

I think thats your problem good luck and let me know

[Technical Support]

Re: GTX wont idle or start in water runs rich

Clearance must be measured without the o-ring and needs to be between 0.010" - 0.014"

[toolguy]

Re: GTX wont idle or start in water runs rich

My rotary valve is within tollerence.
My spark seems to be weak and now intermittent.
I have checked and cleaned every connection in the entire electrical system including all grounds.
Should I replace the MPEM, Module, coil or start in the flywheel area for diagnostics?
Any help is greatly appreciated!

[dboysmith]

Re: GTX wont idle or start in water runs rich

I have a similar problem with my 92 GTX. I rebuilt the carbs and adjusted the Rotary Valve timing. It seemed to run fine out of the water on trailer.
Once in the water, it ran terrible and smoked like crazy.

Couple of questions for you guys:
1) When putting the rotary valve on, how far should it be pushed onto the gear that it rides on?
2) If I had a crankcase cover bolt misthread (so now it will not tighten), whould this cause the the symptoms described above? Someone told me that it may be sucking in air due to an improper seal (like only having 3 out of 4 bolts holding the cover)

[kiohio]

Re: GTX wont idle or start in water runs rich

Watching this thread..... SOunds like my '97 GSX. Rebuilt carbs, new SBT motor, started great on the trailer, first poke at the starter. Once in the water it won't start unless I hold the throttle wide open from the very begining with NO choke. Plugs are absolutely soaked in gas. Runs rough for 200 yds or so then doesn't miss a beat, until you shut it down and let it cool.
BTW running a block off kit and 40:1 Mixture with Seadoo Synthetic oil.

KO

[geomo]

Re: GTX wont idle or start in water runs rich

Working on recently purchased used 97 gtx. (see thread "new carb or rebuild") Now it starts and runs thanks to correcting fuel lines incorrectly installed. Problem is it's running extremely rich and only when WOT. I can start it if I turn off the fuel line then WOT and open fuel line. Can't even start it WOT with fuel line on. Thought it might be idle screws open too much flooding engine because pinching off fuel supply eventually starts it up. Then it will idle at 3000 for a few minutes until it gets fuel starved. Then I open the fuel line and it stalls unless I go WOT.