98 xp limited with 951 rotox bogging down at idle to 4,500 rpm’s. But runs like a champ from 4,500 to 7,800 rpm’s.

[shelford777]

I inherited this 1998 Seadoo xp limited from my dad. It had a blown engine so he had the shop put in a new engine. But it was getting starved of fuel so he put it in storage. 7 years later I pulled it out and had a local guy go thru it and clean the carbs. Last summer everything plugged up on my first ride so I pulled it and put it in my shop till I had time to replace the fuel lines. I have now replace all the fuel lines, new fuel water filter, new selector valve, rebuild the carbs two times, new plugs two times and trimmed the cable on the boots. I adjusted the high side from zero to 1/4 and low I’ve bounced between 1 1/4 to 1 3/4.

The ski starts great and idles at 1400 at start up and sounds great. As soon as I give it throttle it starts to bog down and sputters. I can work the throttle and ever it up over 4,500 rpm’s and it takes off and runs great between 4,500 to 7,800rpms but starts to rattle at 7,800rpms. When I let off the gas and it drops down under 4,500 rpm’s it starts to big down and stall out. But it starts idling at 2,000 rpm’s once it’s revved up. I can pull the choke and it will start to die but will start idle back at 1,400 rpm’s.

I’m clueless to what else to do. Any help would be amazing.

 

[shelford777]

I also cleaned the fuel tank

 

[JC-SUPERJET]

Inspect and clean the Power Valves.

 

[mikidymac]

It's your carbs.
Follow the carb rebuild sticky exactly and only use all new OEM Mikuni parts.

I see you replaced the accelerator pump lines and I see you did not reuse the restrictor orifice that has to be in them. This is most likely your bogging issue. The restrictor orifice is #18 on the carb parts diagram for your ski.
Make sure your accelerator pump is squirting fuel into bot carbs.

The hanging idle could be either the carbs, the throttle cable being too tight or and air leak.

Low speed screw should be at 1-1/4
High speed MAG should be 0 PTO should be 1/4.
Since you are way off on yours something is wrong.
Idle should be 2,800 out of the water, 1,400 in the water.

"It starts to rattle" at 7800 rpm is detonation because you are lean. STOP RIIDING IT! or you are going to blow a hole in the piston with detonation.

 

[shvinas]

How it reaches 7800 on water. Cant believe that.

 

[shelford777]

It's your carbs.
Follow the carb rebuild sticky exactly and only use all new OEM Mikuni parts.

I see you replaced the accelerator pump lines and I see you did not reuse the restrictor orifice that has to be in them. This is most likely your bogging issue. The restrictor orifice is #18 on the carb parts diagram for your ski.
Make sure your accelerator pump is squirting fuel into bot carbs.

The hanging idle could be either the carbs, the throttle cable being too tight or and air leak.

Low speed screw should be at 1-1/4
High speed MAG should be 0 PTO should be 1/4.
Since you are way off on yours something is wrong.
Idle should be 2,800 out of the water, 1,400 in the water.

"It starts to rattle" at 7800 rpm is detonation because you are lean. STOP RIIDING IT! or you are going to blow a hole in the piston with detonation.

I have tried to order the restrictor orifice 3 times now. But everyone is sold out and ends up refunding my money. Do you know where I may be able to get my hands on one?

 

[mikidymac]

Westside Powersports Seadoo.

 

[shelford777]

Westside Powersports Seadoo.

thank you so much.

 

[shelford777]

I replaced the accelerator pump, fuel line. But it’s doing the same thing. Low end it wants to stall out, above 4,000 rpm’s it runs great. The bow spark plug is dry and looks good, The aft plug is very wet.
I replaced the plugs, boots and clipped back the cable. And still the same.
Rebuilt the carbs 2 times and did pop off test. Replace fuel lines, selector valve and filters. Accelerator pump does pump and looked good.

Any thoughts? I’m about to just sink this damn thing to the bottom of the lake.