Slow acceleration when fully turned, full throttle.

[Venturian1]

If the boot does not hold the carbon seal firmly against the stainless steel hat then air can leak into the jetpump during hard acceleration. To replace the boot you need to remove the driveshaft and you will be able to inspect the mating surfaces of the carbon ring and steel hat. If either surface has deterioration then it would be best to replace all the parts. If you accelerate hard from a dead stop in a straight line does the engine Rev real high and then it takes off after starting to move slow at first (like a slipping clutch)? That is the problem I had with a 96 GTX and replacing the boot, carbon ring and steel hat solved the issue. I also use a neoprene ring to seal the jetpump to the hull because that is another place where air can leak into the pump.

Good post! There must be a lot of vacuum around the driveshaft, and if air can get in, it will.
I prefer the old needle bearings and rubber seals, and a grease zert.

 

[Venturian1]

Hello! I have a 1997 Seadoo GTX that I purchased used. When turning the handles all the way to the right or left, and opening up to full throttle, it doesn’t want to accelerate then takes off. Not sure if it is carb related, or carbon seal/boot. Took a look at the driveshaft and the boot does not snug up against carbon seal and won’t stay flush. Would this boot cause issues with turning/slow acceleration with throttle wide open?

When you rebuild the carbs, be sure to set the pop-off pressure as close to the same for each carb, 30 psi is what I’ve been using, that took care of my hesitation issue (97 gsx), test the fuel selector valve using vacuum, and you should disassemble it and lubricate the rubber with silicone grease. Check the OEM fuel filter for tiny tears around the bottom, and lubricate the O-ring and plastic threads with silicone grease too.
The rave valves are critical. If exhaust gasses get through and leak out, there goes your tuned pipe performance, and a rave or two melt down inside, and that will compromise performance.
If you’ve never rebuilt one of these carbs, I always start with the hand operated vac/pressure pump. The manual is available free, just search for seadoo manuals free pdf. Free pdf Parts catalogs too. Everything you need to know.
If you replace the fuel pump valves (clear plastic discs) in the front carb, the book will show you what tool you need. I found a straight pin (sewing) that had the 2mm ball on top, chucked it up in a holder, works great as long as the rubber is soft and pliable and coated with silicone grease (dielectric compound, auto parts store).

 

[Sd97gtx]

Figured I would provide an update after working on the jetski over the winter, and testing it in the water today.
1. Cleaned flame arrester it was plugged and needed lots of cleaning.
2. Water regulator was several rotations different than manual spec. Rave valves gaskets were leaking and were replaced. Also, the rave valves were turned in all the way. Made them flush like manual recommends.
3. Idle speed was less than what manual recommended, and increased it to 3000 rpm out of water.
4. Low speed and high speeds were way off. Person before me had both Lows at 0 turns, highs at 2-3 out. Set those to manual specs.
5. Made sure oil pump lines matched up. They are very close, but I have it a tad rich.
5 . After doing this I hooked the jetski to the hose and revved it up. Found an exhaust leak where water was spraying out. Funny how that sprang up after adjusting the idle speed. Took the bad gasket out, replaced it with new one.

Rode it several hours today. And I am now at 6600 rpm’s WOT, where I was previously 5500.
It hesitates for not even half a second before it takes off. But you can tell it’s not instant. Probably need to adjust lows out a tad more.
Performed a plug chop after 1 min at full throttle. Both plugs looked good. Cylinder 1 was more lean than 2 (touch of grey), but both had some mocha.
I just want to thank those of you who answered my questions and truly wanted to help. I hope someone finds this post one day and it helps them solve their issues.

 

[POPPS]

When you said there isa touch of “gray” on the plug, that concerns me,,plugs should have shades of brown, not gray, which usually indicates metal from the piston. I would do a compression test on that cyliner.