Seadoo runs fine for 10-15 minutes and stops.

[Ezrajohn]

I have a early 90’s seadoo xp with the 717,I runs great for 10-15 minutes top end and low,after riding for that time it starts to bog and then won’t go over 10 mph,revs high but goes slow,it’ll suddenly kick up for a second and then slow down again,if I let it sit do 10 minute it’ll rip again for a few minutes than do the same thing,is this a carb issue? I’ve changed my plugs,new gas,new oil,it is sucking water and pissing,so it’s cooling,I’m kinda stumped,it ran fine last year and now I’m having this issue, I sincerely appreciate it! https://imgur.com/gallery/1FRPOA1 Here’s a video.

 

[Ezrajohn]

I have a early 90’s seadoo xp with the 717,I runs great for 10-15 minutes top end and low,after riding for that time it starts to bog and then won’t go over 10 mph,revs high but goes slow,it’ll suddenly kick up for a second and then slow down again,if I let it sit do 10 minute it’ll rip again for a few minutes than do the same thing,is this a carb issue? I’ve changed my plugs,new gas,new oil,it is sucking water and pissing,so it’s cooling,I’m kinda stumped,it ran fine last year and now I’m having this issue, I sincerely appreciate it! https://imgur.com/gallery/1FRPOA1 Here’s a video.

Could it be the gas tank not holding pressure? I don’t think it’s the carbs it’ll run great for the first 10-15 min but after that it’s boggy but never dies during idle,maybe the tanks check valves aren’t holding air?

 

[burtshaver2021]

When you said rêve high but goes slow I was going to say driveline, prop, wear ring. But after watching the video I wouldn’t t say it’s Reving high and going slow. Sounds almost as if it’s running on 1 cylinder. I would do a plug chop after running it like that and see what the plugs look like. Take a compression test as well and after you do the plug chop I wouldn’t ride it anymore till you get it figured out or you risk damaging the engine if it’s not already.

 

[burtshaver2021]

But I guess it wouldn’t hurt to have a look at the west ring and prop anyways though, lol.

 

[Ezrajohn]

When you said rêve high but goes slow I was going to say driveline, prop, wear ring. But after watching the video I wouldn’t t say it’s Reving high and going slow. Sounds almost as if it’s running on 1 cylinder. I would do a plug chop after running it like that and see what the plugs look like. Take a compression test as well and after you do the plug chop I wouldn’t ride it anymore till you get it figured out or you risk damaging the engine if it’s not already.

Sounds good I’ll check,I don’t think it’s running on one cylinder as it rides normal for 10-15 minutes then it does what the video shows,I let it sit for 5 minutes off and then it runs great again,it’s definitely weird I think it’s a fuel or spark issue,maybe the coil pack when it heats up stops firing on both but when I let it sit it cools enough to run fine,it’s weird for sure,I’ll check compression tomorrow,thanks!

 

[Ezrajohn]

But I guess it wouldn’t hurt to have a look at the west ring and prop anyways though, lol.

Brand new wear ring and prop is not the greatest condition but it doesn’t point to those in the sense that it will run great after launching it for 10-15 min and then do what it did in the video,after I shut it off for a few min it runs great again and then does the same bs not long after,I was thinking fuel but idk tbh

 

[mikidymac]

check your fuel tank vent check valve. It souls let air flow n but not out.

 

[Ezrajohn]

check your fuel tank vent check valve. It souls let air flow n but not out.

So you think it could be the tank not holding pressure also?

 

[mikidymac]

The opposite. It could be creating a vacuum and starving for fuel. Pressure is good, vacuum is bad.

The stock system should let air in not out, that’s why there’s a check valve in the vent line.

 

[burtshaver2021]

I think Mikidymac is correct. When it starts running poorly just crack the gas cap open while riding, of course being careful not to splash water into the tank

 

[Ezrajohn]

I think Mikidymac is correct. When it starts running poorly just crack the gas cap open while riding, of course being careful not to splash water into the tank

I didn’t even think of that I appreciate the insight guys,will trace out the vent line and report back

 

[Ezrajohn]

Y

The opposite. It could be creating a vacuum and starving for fuel. Pressure is good, vacuum is bad.

The stock system should let air in not out, that’s why there’s a check valve in the vent line.

You think one of my check valves could be bad?

 

[mikidymac]

Could be.
Problem with the early skis is the gas cap is really low. Don’t get water into the fuel tank.

 

[Ezrajohn]

Could be.
Problem with the early skis is the gas cap is really low. Don’t get water into the fuel tank.

It seems to be decently high on mine,right side of the center column above the seat, I’ll try with the gas cap loose or off and see

 

[Ezrajohn]

check your fuel tank vent check valve. It souls let air flow n but not out.

You were right the smaller check valve that is rated to let it at 1.5 psi wasn’t stopping the plunger in it is dry rotten,after removing and blowing into the vent line and covering with my thumb the tank holds pressure now,also weirdly the gas tank hose clamps were off on the fill side and tank side so I’m sure that wasn’t helping at all,thanks again Mac

 

[Ezrajohn]

Mac was right,this check valve is no good!

 

[mikidymac]

There’s actually two. One only lets air in so the tank can’t build vacuum and starve for fuel. The other one is a pressure relief so the tank doesn’t build excessive pressure.