Normal idle out of water and no idle increase (solved)

[AJF22]

I have an 01 GS and I want to know what is a decent idle out of water? I’ve seen 2500 and 3500 rpm?
My issue is after rebuilding the carb, high idle screw is all the way in, backed out the lower idle screw 1-1/2 turns, ski idles at 2300.
I backed out the LIS another full turn and the idle didn’t change.
So I’m also curious why the idle would not increase? Is there something else that needs to be adjusted?

 

[burtshaver2021]

There is a low speed screw and a high speed screw, they should be se to factory specs. and then the idle screw should be adjusted so that it idles at 3000 rpm out of the water or 1500 in the water

 

[AJF22]

Yes both the the low speed screw and high speed screws were set to factory specs. To get it to 3k rpm I’m having to adjust the throttle linkage. Adjusting the low speed screw out pass specs of 1-1/2 turn does nothing to the idle speed, as currently I have the low speed screw adjusted out 3 full turns and it’s still idling at 2500.

 

[burtshaver2021]

Yes both the the low speed screw and high speed screws were set to factory specs. To get it to 3k rpm I’m having to adjust the throttle linkage. Adjusting the low speed screw out pass specs of 1-1/2 turn does nothing to the idle speed, as currently I have the low speed screw adjusted out 3 full turns and it’s still idling at 2500.

And the low speed screw should not have an effect in the idle, once it’s set to factory specs it should pretty much not be turned except maybe an 1/8” or so if it’s not running correctly. There is an idle screw that you should be adjusting, I believe it has a slot for a straight screw driver, the low speed screw has a T handle and the high speed screw has a plastic cap that needs to be removed in order to adjust. The way your message reads, it sounds like your turning out the low speed screw to adjust idle and that’s incorrect

 

[AJF22]

And the low speed screw should not have an effect in the idle, once it’s set to factory specs it should pretty much not be turned except maybe an 1/8” or so if it’s not running correctly. There is an idle screw that you should be adjusting, I believe it has a slot for a straight screw driver, the low speed screw has a T handle and the high speed screw has a plastic cap that needs to be removed in order to adjust. The way your message reads, it sounds like your turning out the low speed screw to adjust idle and that’s incorrect

Thank you, this is exactly what I was thinking.
I know there should be an idle screw but I do not see it. I have the service manual, but maybe in my rush of looking things up, I didn’t see where the idle adjustment screw is and I failed to look for it when I had the carb off. I looked for the Mikuni service manual, but I do not know exactly what model carb I have?
Plus now with the carb back on, it’s hard to get a good sight on things.

 

[burtshaver2021]

Sea Doo PWC Carburetor Reference
You have a BN 40I-38 with accelerator pump. I attached the Seadoo source page, comes in handy for specs and part numbers. Yes, the idle screw is very difficult to see with the air box on, at least on the 95XP it is.

 

[AJF22]

Sea Doo PWC Carburetor Reference
You have a BN 40I-38 with accelerator pump. I attached the Seadoo source page, comes in handy for specs and part numbers. Yes, the idle screw is very difficult to see with the air box on, at least on the 95XP it is.

Right on, thanks

 

[mikidymac]

As Burt has said you are adjusting the wrong screws.
The screws on the aluminum body of the carb going into the side of the carb are NOT the idle screws. You need to set both of those back to the factory spec.

The idle screw pushes the wheel on the side that the throttle cable attaches to.

 

[AJF22]

Thank you.
It seems in the Mikuni manual they don't call it an idle adjustment screw, but a "Idle Stop Screw", so I'm assuming this is what I'm looking for to do adjustments?
Here's a picture of my carb. So now I see why it was a bit hard to see with the carb on, it was blocked by the side plate..

 

[mikidymac]

Yes that is what adjusts idle speed.
Make sure the throttle cable has a little slack in it and not holding the throttle open.

 

[AJF22]

Yes that is what adjusts idle speed.
Make sure the throttle cable has a little slack in it and not holding the throttle open.

Thank you for the reminder, I did have the throttle cable set high to gain a better idle. I will make sure that and the idle stop and everything are adjusted properly.
Again thank you

 

[AJF22]

Thank you for help! Got the carb tuned and so far so good. Adjusted the throttle cable and the idle stop screw and got it in it’s sweet spot, idles great at 3,000 out of the water.

 

[Grim]

IMO, while getting it set around 3000 out of water is good (more of a place holder), the real number you want is in the water. Make sure you are at about 1400 to 1500 in the water, I have had to adjust mine almost every time. I would suggest running it for a few minutes after each adjustment to get it "set in". It took about three trip on mine to get it dialed in to close to 1400 (that's what I like it at) After you have it set in the water, don't mess with it out of the water.

 

[AJF22]

IMO, while getting it set around 3000 out of water is good (more of a place holder), the real number you want is in the water. Make sure you are at about 1400 to 1500 in the water, I have had to adjust mine almost every time. I would suggest running it for a few minutes after each adjustment to get it "set in". It took about three trip on mine to get it dialed in to close to 1400 (that's what I like it at) After you have it set in the water, don't mess with it out of the water.

Thank you for that info. I'm hoping next weekend I can get it dialed in on the water and that's a helpful suggestion to run it around till it gets set in.