96 gtx 787 dieing

[matthechat]

This seadoo and I have a long history. I've had it for about 5 years. After giving up on the local boat shops I decided to work on it myself. I'm mechanically inclined, just didn't really care to add it to my list of specialties haha. Well after 2 years of a crappy seadoo and a blown up engine I found the clogged fuel selector switch that the shop couldn't. It never really ran great like I thought it should even after rebuilding the carbs. I never thought to adjust the needles in them till recently when it started fouling plugs. My 96 gtx with a 787 had the high speed screws 3/4 of a turn from closed and the low speed screws 1 1/4 turns from closed. I read on a site that 96 gtx stock needle positions are: low speed 1 turn and high speed 0. So I made the adjustments and took it out. It ran better then ever! but after about a mile it died, kinda bogged down over a few seconds then died. When I tried to start it it wouldn't turn over but after about 30 seconds it turned a lil. And then in a minute or two it fired right back up. I took it real easy back to the dock. I'm just wondering if these needle settings sound correct to you guys? I'm afraid of running it lean and blowing the engine :ack: Does this sound like I perhaps almost seized the engine? I don't really think it got hot and the plugs didn't look white. Although I don't really know what to look for in plugs Any suggestions on what I should do?

 

[nswillin]

Hey man. Your right on the carbs specs for the Low/High speed settings. Remember: Turning screw 1/4 turn counterclockwise enriches mixture and turning screw clockwise leans mixture.

Here is some threads that will help you out.

http://www.seadooforum.com/showthread.php?t=3554

http://www.seadooforum.com/showthread.php?t=4151;

 

[mdesjard]

Watch out my friend

If your engien was rebuilt , it can need more gas, start on high speed screw adjustement at 3/4 and lean it smoothly.
It's more secure.

 

[matthechat]

It was about 2 years ago that it was rebuilt (not really rebuilt, new block) and It's been run probably 20 hours since then. I did the proper break in procedure. So should I leave the low speed where it is and turn the high speed to 1/2. It was at 3/4 and fouling plugs. I'm just guessing here. I have no experience with adjusting these things. I know that these carbs are supposed to have a cap on the high speed screw, mine were gone. Thanks for the replies thats a good read nswillin, i'm reading the 2nd link right now. I guess I should probably richen it until I notice a hit in performance and then turn back to next level of "leanity" (new word ) and avoid any chance of running lean.

On second thought, should I leave my high speed needle at 0 (stock spec) and increase my low speed 1/4 turn? Also, i'm confused about the different carb setting for skis with the same engine. Are there different carbs for different models with the 787? Thats the only thing i can think of...