Seadoo SP running weird

[KyleW2]

Went to take my 95 SP out yesterday and it wasn’t going faster than around 5 mph. Pulled it back on the trailer, revved it up and it wouldn’t rev all the way up without hesitating. Switched the fuel switch to “On” and it would rev up near full rpms but would start surging. Sound like a fuel issue? Put new plugs in it this morning, no change. Checked external fuel filter, clean as new. I assume I am having an issue with fuel flow, and probably not a carb issue since it changes with the fuel selector switch? All lines are black fuel lines. Does this sound like the fuel selector is going bad? Any tips to check let me know. I am going to start going through the fuel system piece by piece.

 

[KyleW2]

Pulled carb back off. Is there a surefire way to see if the mylar check valves are in backwards? Had excellent fuel flow in the inlet to the carb and in the outlet line. However, the mylar valves had some gas underneath them so I’m wondering if I installed them backwards on accident. Carb filter is spotless.

 

[97explorer717]

If I I'm thinking about what you're talkin about correctly I laid mine on a flat surface and could see which way they were curved. Also I'm not a professional but from Reading several post what about the rectifier? You could unhook the red wire apparently and see if it straightens out. Battery has to be fully charged. My understanding of it is that it just runs off the battery when you do that.

 

[KyleW2]

Thanks, I will keep that in mind. Since I am getting plenty of fuel and the ski is starting easier than ever, I assume the fuel pump is indeed working correctly. I am going to bypass the fuel selector today and see if that helps. If so I will go buy a new one in the morning

 

[JeremyD615]

You’re on the right track. Bypass the selector and see if it clears up. It sounds like you’re getting an air leak, so don’t even attempt to clean the selector, just replace it.

 

[KyleW2]

Looking in the hull there is a black line connected to the right side of the ski that leads nowhere. Is that supposed to connect to the gas tank somewhere? It is a thru-hull fitting.

 

[KyleW2]

It is running way better on the trailer now after bypassing the selector switch Hitting the rev limiter with no bog or hesitation before hand. Going to pull it out to the water this evening and test it with the load on the engine. Tomorrow morning I will go get a new fuel selector switch.

 

[KyleW2]

Still no luck. Still running bad. Have checked spark, excellent spark. Trimmed back the wires and new plugs and still same issue. If I pull the choke out it dies so I’m getting fuel flow. However, after it dies with the choke - if I turn the choke off and restart it it will ride for about 2 seconds picking up speed before it starts to bog back down to around 5 mph. Anything else to check?

 

[JeremyD615]

Did you ever actually verify that the check valves are installed correctly? Another thing to check is your fuel tank vent line. If the outlet is plugged, it can build up quite a bit of pressure and do some funky things. That’s fairly rare, but it does happen...

 

[KyleW2]

Did you ever actually verify that the check valves are installed correctly? Another thing to check is your fuel tank vent line. If the outlet is plugged, it can build up quite a bit of pressure and do some funky things. That’s fairly rare, but it does happen...

As far as I know they are in correctly. I was able to blow into the inlet but not suck out and I was able to suck out the outlet but not blow in. I did take the check valves out as well and the curve appeared to be the correct way on both sides

Edit: It is also worth noting that I did have the ski out after rebuilding the carb and it ran perfect. This is a new issue since redoing the oil pump and gasket

 

[JeremyD615]

I’d move on to checking the vent line next then... Use an air compressor or bicycle pump to pressurize the tank, and you should see/hear it release at 2-3psi.

 

[KyleW2]

Found a few loose hoses on the gas tank. Got them tightened. Is there a surefire way to test the rectifier based on voltage or do I have to disconnect it to test it? Still waiting for a new selector valve then will take it back out and test it. Should have that by Wednesday

 

[mikidymac]

With the ski running at about 4,000 rpm the battery should test out at about 13.5-14 volts.

 

[KyleW2]

Seems the rectifier tested bad. I will go ahead and replace it tomorrow, cheap insurance either way.

Will be replacing the fuel selector in the morning as well.

In a previous post I mentioned a check valve on the right side of the ski (if standing behind it, aka starboard side) with a hose not connected to anything. Is this supposed to hook into the top of the oil tank on the one nipple not used for the rotary valve return line?

 

[mikidymac]

No, nothing hooks to the check valve on the oil tank.

The mystery hose is probably for the battery vent on flooded cell batteries.

 

[KyleW2]

Same issue. New rectifier and fuel selector today. Fuel system holds pressure and opens around 3 psi. Guess I need to look at rebuilding the carb agaib

 

[KyleW2]

If I rebuild the carburetor again I am going to go ahead and order a new needle and seat. Is 2.0 correct for a 1995 SP (single carb)?

 

[JeremyD615]

Yes, the 2.0 is correct.

 

[KyleW2]

Thanks.

Since I have two threads going about two different issues, I am wondering if my issue is linked to the oil leak.
IF my oil leak is coming from the rotary valve cover o ring - would this cause an air leak thus causing my running issue on the lake over a few mph?

 

[mikidymac]

An intake air leak will usually cause a runaway when on the trailer.

 

[KyleW2]

Officially fixed the oil leak, leak free now..However now I am having an idle of around 4000 on the trailer that I can’t seem to adjust. So I guess I have an air leak somewhere now. If I do, it must be a very small one, as it only increased rpms by 1000 but still will not run it until I find the leak. Back into it I go I guess

 

[mikidymac]

Are you sure you have slack in the throttle cable?
Oil cable is in the correct position?
Idle screw backed out?

An air leak will typically cause it to go full throttle, not just 4,000 rpm.

 

[KyleW2]

Even a small leak will cause full throttle rev up?
It is entirely possible it is something I didn’t hook up correctly. That would be a huge relief!
I backed the idle screw out, no change..Oil cable is connected correctly. I will unhook the throttle cable to rule that out before I do anything else. It is just a fast idle, revs up and back down with throttle but I only let it run for a few seconds just in case it is running lean.
I replaced the rotary valve cover o ring as well as the intake manifold to rotary valve cover o ring. 24 hours in and so far, no oil under the ski. I just hope neither one of those is leaking air and causing this issue.

 

[mikidymac]

I have never seen an air leak just cause a high idle. If it is enough to leak air they will runaway but heck, anything is possible. I would double check your throttle cable.

You should have 1-2mm of play on the throttle lever before the carbs move and you should hear the carbs snap closed when you snap the throttle closed.

 

[KyleW2]

I have never seen an air leak just cause a high idle. If it is enough to leak air they will runaway but heck, anything is possible. I would double check your throttle cable.

You should have 1-2mm of play on the throttle lever before the carbs move and you should hear the carbs snap closed when you snap the throttle closed.

You saved me about 3 hours of frustration and two cases of beer by telling me to check the throttle cable. Adjusted it and we are back down to a little under 3000 on the trailer. Will fine tune it on the water