90 seaDoo SP tuning question

[dale23]

Need help getting my 90 seadoo SP running. Just replaced plugs, battery, fuel filter and complete rebuilt carb an fuel pump. Aligned oil pump throttle properly.:rant: Can get to start no problem but have to stay on the throttle, after about 10 seconds it seems like it floods out and shuts off especially when I try to get it to idle. Any suggestions or advice would be appreciated.

Regards, Dale

 

[seadoosnipe]

Low speed screws...?

Have you adjusted your low idle speed screw to 1 turn open? I hope, during the process of rebuilding, you didn't tamper with the high speed screw. This is factory preset and has a black cap on top of the screw head, to only allow for a 1/4 turn adjustment either lean or rich.
It does sound like your getting way to much fuel. What do your spark plugs look like after it drowns out? Are you trying to start the motor on land with the water hose?

 

[dale23]

good Question

I know the low speed idle screw as the one w/ the spring on it connected to the throttle lever. This one I have not touched. Upon rebuilding the carb, the only adjustment screw I removed and cleaned was a small brass screw, w/ a small hole in the end, inside a hole. There was not a cap on top of it but it looked like a plug type cap could fit inside of the hole that the screw was set in.
Before removing, I checked the screws position by turning it clockwise, it was tightened all the way, therefore I thought it was ok to remove it since it did not have a setting. I proceed to clean it and make sure the hole was not blocked.

This was the only screw on the carb so I assume it is the one you are talking about, please confirm?

Running it was dry and on the trailer. Once I get it running I will turn on the water. Is this method correct?

Thank you!

 

[dale23]

running rich

o.k., I re-adjusted the low speed idle screw to about 1.5 turns. Cranked it up and idles great, even revs up nice. However I put it in water and it won't go over idle speed and alot of white smoke. Seem like it's running rich but why can't I get on plane?

 

[kustomkarl]

Dale, yes start the doo first than turn on the water to run it on the trailer. Turn off the water than shut down the doo. This keeps the water pressure from entering the engine. What do the spark plugs condition look like. They might have gotten fouled from the first time running. They can be cleaned up and reused again. That's a 1990 sp... have you done a compression check? the compression at best should be 150psi if it is low it might be your problem. If the compression is below 100 than it might need some TLC to get it back in shape. Do you know how to do a compression check? If not let us know and we'll give you the info to do it properly. You will need a compression guage to perform it. With a little more info I'm sure we can help you get it in running shape.

Karl

 

[dale23]

Good compression

Yep, did a compression check and got about 150. Have'nt checked the plugs but why would it rev up great out of the water vs in the water if the plugs are fouled? Would'nrt it run rough at any speed? I'll give them a look when I get home this aft.

Thanks,Dale

 

[ScubaDoo]

In the water the doo is under load from the impeller in the water( it's a direct drive system). The compression is great and tells us that the engine is in good shape. Be sure that both low speed screws and high speed screws are at the same setting, on each carburetor.( Does it just bog down and die when you accelerate in the water? Can you ease the gas to make it accelerate?

 

[dale23]

carburator

My ski only has one carb. The high speed screw, I assume, is on the side and is set in deep. When I purchased the ski it was tightened all the way to the right. With it set like this I even road it fast for about 6 miles - no problem. Thereafter the troubles began so I rebuilt the carb.
Now I can only idle along. If I give it full throttle it won't accelerate and bog down and quit.

 

[ScubaDoo]

Let me pull up the manual on the 90 SP and give it a look see...

 

[ScubaDoo]

Dale, I checked the manual and it appears to have a low speed screw(with a spring) and an Idle speed screw. The low speed screw should be adjusted between 1 1/2 turns out to 2 turns out from seated position. The other screw is a idle screw adjustment. It doesn't have a high speed screw adjustment.
Now when you "rebuilt" the carb was the float arm inside the carb,(has small spring under it) parallel to the carb chamber body? Did you blow out all the passages out with compressed air? What exactly did you do to rebuild the carb? On this model in the manual it claims that the models prior to 1991 do not have a integrated fuel pump. Did you do anything to the fuel pump? It sounds like it isn't getting gas...like it has fuel pump problems. Let me know this info so we can go on further.

 

[dale23]

carb

After thoroughly rebuilding the carb and fuel pump 3 times, w/ no luck, I bought a complete rebuild kit + needle valve and seat from my local Seadoo shop. I cleaned and blew out all passages where gas flows and installed the new parts. Re: the rocker arm, I replaced it exactly like it was. I'm not sure what you mean about being paralell w/ the carb. I have read that the rocker arm needs to be bent to a certain height but I have not touched it. Is this correct?
Just checked the plugs and they were not wet but on the dark side w/ a little bit of build up. Cleaned and replaced.

 

[ScubaDoo]

The float arm has a spring under it and controls the needle valve in the needle and seat. If you look across the arm it should be parallel to the surrounding body of the carb. (also known as the chamber body) It should not be at an angle higher or lower than the carb body. Ok, if you did a complete rebuild of the carb and the fuel pump than it should not be an issue. I would check the adjustment of the low speed screw(on the side with a pin through it and a spring), and adjust it to 1 1/2 turns out and make sure the other screw is in tight. That screw is the main jet. Fire it up and give it a try. Adjust the low speed screw out a 1/8 turn at a time and see what it does to help. Don't go much further than 2 total turns out. Also try going in about 1/8 turn at a time. Be sure you don't have any air leaks around the carb or manifold check all attaching bolts and screws, I'm sure you've done that already. It's just a process of elimination to figure out the problem.

 

[dale23]

dry run

Should this be done in the water? Because when flushing it out of the water everything runs great, doesn't stall and revs up good. Or is there a way I can create a load to simulate the problem?

 

[ScubaDoo]

Dale you'll have to have it in the water to have a load applied on the jet pump. The jet pump has no load on the hose and will not be accurate.

 

[dale23]

Running but..

I took it out on the water today and adjusted the screw. It seems that one screw operates both the low and high speed. When it was out more than 1.5 turns it idled great but would not plane. When I turned it to 1 or even 3/4 turns it ran incredible on top end but would not stay idling in the water. I think I need to set the idle screw more but my screwdriver would not fit while water tesing.

Now, I after all of that and claiming victory, it won't start. The plugs look great but dry and sparked good. . I removed the fuel hose from the carb and cranked and it's pumping fuel. What may have gone wrong in the carb to stop it from getting fuel? I've even got 2 fuel filters in line before the fuel pump.

 

[kustomkarl]

I think you only need I filter in line, but 2 shouldn't do any harm. The only adjustment on the single carb model is the low speed adjustment. The other screw adjusts the idle. I would adjust the low speed screw to the 1 1/2 and adjust the idle to idle at about 2500 rpm's under load in the water, or 3000 rpm's on the trailer, on the hose. (If on the trailer don't run it more than a few minutes as it will overheat the impeller bearings and seals, being out of the water.) Than adjust the low speed accordingly till it performs good at low to high speeds. The Idle speed shouldn't be adjusted with the low speed screw. It might be too lean a mixture and cause problems. Don't adjust it in more than 1 turn from seated. Use the idle screw for the idle speed. There are no other screw adjustments you can do to the carb.

Karl