98 Seadoo GTI not getting up to speed PLEASE HELP

[adam368741]

Okay before anyone says look it up I have at least 15 links saved in my browser right now.
So the problem is when I took it out today for a test run I couldn’t go over 23ish WOT.
The back story is I replaced the grey tempo 1/4 lines because the ski sat for a couple of years drained
the old gas and put new gas replaced the oil injector lines 3/32 and I rebuilt the Mikuni
BN40i carb I’ve read several sources that make me think the high speed adjustment should be set at 1.5 turns but I’ve also read that it should be set on 0 turns. My plugs are great shape no fouling etc. I can hit the throttle going idle speed and there’s great response but when I get up to 23 ish it seems like that’s all it’ll go should I set the high adjustment to 1.5 turns and try it ? Or am I looking at a different problem? Also this is the silver engine and single carb.

[Myself]

Re: 98 Seadoo GTI not getting up to speed PLEASE HELP

You're running way too rich. High should be 0 but i usually crack them open just a bit. Set low at 1.5 out.

[freekstyle]

Re: 98 Seadoo GTI not getting up to speed PLEASE HELP

Did you remember to untie the anchor bag?

[hafweigthr]

Re: 98 Seadoo GTI not getting up to speed PLEASE HELP

What are your max rpms? Based on what I read your ski was running ok and you decided to change the fuel lines and go through the carbs and now your ski will not run correctly--is that correct? if that is so it is something you did and I would bet on the carbs.

Have speed or less could be a spark plug not firing - pump wear ring - CARBS - bad rev limiter.

[adam368741]

Re: 98 Seadoo GTI not getting up to speed PLEASE HELP

Just rebuilt carb and the wear ring is in good shape I set carb again today and it’s set I’m wondering if the fuel baffle screen is clogged because it sat for so long the impeller and wear ring look great and are in tolerance also the idle is nice and smooth now that I adjusted the carb where it should be it’s like I’m starving for fuel at 20 there is no rpm gauge on this model but the rpms stay right at where 20 would be it doesn’t high rev like it would if it were cavitating

[Myself]

Re: 98 Seadoo GTI not getting up to speed PLEASE HELP

If you turned in the high speed screw and it got worse then you have a fuel delivery issue instead of a pig rich issue. Could also have some other issue. What do the plugs look like?

[adam368741]

Re: 98 Seadoo GTI not getting up to speed PLEASE HELP

Plugs are in good shape and it runs great out of the hole but it seems like I’m having fuel restrictions. I will be pulling the baffle today and removing the screen off of it as I have an inline filter now.

[Myself]

Re: 98 Seadoo GTI not getting up to speed PLEASE HELP

I've never seen a baffle screen cause an issue on a Seadoo. The stock fuel filter cup o'ring on the other hand.....will. Also the fuel switch could be sucking air or any number of things during carb rebuild.

[adam368741]

Re: 98 Seadoo GTI not getting up to speed PLEASE HELP

I’m thinking about bypassing the main tank and going straight to the carb with fuel. Just to see if that makes a difference. I didn’t get time to tinker with it much today. I just had another thought the inline filter I added while swapping the lines is 1/4 inch so the inside diameter is smaller could that cause this I’m really at a loss for words on what to try I have another premium carb kit on the way. I don’t think my carb is the problem though the only reason I rebuilt it was because the check valves weren’t holding. Now it seems to be pumping fine. The fuel tank baffle screen was clean as a whistle as was the inside of the tank.

[hafweigthr]

Re: 98 Seadoo GTI not getting up to speed PLEASE HELP

I have tried inline filters on several skis and if not installed correctly and the proper type they will cause issues. What I found is that I was constantly sucking air into the fuel system and it would run intermittently. If your are pushing gas through these filters from the fuel pump they work well - pulling gas through like on a Seadoo not so well.

If it was fine before and now after rebuilding carbs you have an issue then look back at your carb.

I have rebuilt lots(way to many) of carbs and there is a knack to doing them. Using Mikuni parts is the best option and others can cause problems. Most carbs reworks I do are cleaning and not parts replacement wholesale. I rarely replace all parts. I always replace the seat O-ring and needle O-rings.

Make sure you exit return orifice is open. Besides filters this is the #2 Mikuni carb issue.

Also always check pop off and make sure your needle and seat, and seat o-ring are not leaking by using WD-40.