Looks like Minnetonka4me has everything to get me going :thumbsup: can you guys believe it ran with that stator?!?!!!! And tbh, as shitty as it did run, it ran good considering this! Thx to everyone for helping out. Best part about forums like this is not only did we figure out this problem but hopefully it helps others troubleshoot their problems with the "search feature"
This seadoo is one problem to the next. 97 GTX 787
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Notice the wear pattern on the rotor near each bolt. Looks like all of them are loose and the holes oblonged. I'd replace both that and the stator and all bolts.
When I pulled mine apart it had Green Locktite on the bolts. I guess there's a reason for it!
I wonder if its worth lockwiring them
When I pulled mine apart it had Green Locktite on the bolts. I guess there's a reason for it!
I wonder if its worth lockwiring them
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All new parts are installed, I get 6800 rpm, good power much better than before. I still however have to throttle it a bit at midrange to get it to transition to the high. I turned the lows out another 1/2 turn each and it almost has it taken care of. Should I turn the highs out to 1 turn each? They are currenty at 1/2 out. It seems like it needs a bit more fuel to transition. What do you guys recommend? Soo close to perfect I'm getting excited
Sportster-2001-951C-Stock
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What would I do in this case? First, I'd confirm pop-off and while at it I'd clean the transition ports (bypass holes in Mikuni language) and high speed venturis well with carb cleaner and compressed air. I'd also pressure check the fuel line and make sure the fuel pump is in good condition, all the normal stuff.
Assuming none of that worked, I'd go up one size on the pilot jet. Based on your description, I'm not convinced the high speed circuit is too lean, if sounds like the upper mid range is. I believe in going fat though, then dialing back from there. It's unfortunate there's no external adjustment for the pilot jet but it is what it is, an EPA-mandated lean bog, two-stroke death.
Assuming none of that worked, I'd go up one size on the pilot jet. Based on your description, I'm not convinced the high speed circuit is too lean, if sounds like the upper mid range is. I believe in going fat though, then dialing back from there. It's unfortunate there's no external adjustment for the pilot jet but it is what it is, an EPA-mandated lean bog, two-stroke death.
It's definitely not a high circuit problem, when I enriched it the machine lost top end. I've went both ways on the lows and it runs best at 2 turns out with highs at zero. It could be jetting but as for the pilot shouldn't it be off the pilot at 4000rpm? I don't have the time to rip the carbs down again for the pop off pressure but next time they are off it will get a full carb kit and fuel pump. I'm satisfied with how it's running for now its pretty good. I should also note that it only hesitated at mid throttle if the machine is slowed or barely moving.. Once I'm on plane and going it never bogs or hangs up at midrange.. It seems like the load on the engine and slow speeds is what aggravates the problem
Sportster-2001-951C-Stock
Well-Known Member
Right, that pilot jet will fatten up the mid range without any effect below 30% throttle and negligible effect at WOT although it does still flow at WOT it's not a huge amount like what comes from the high speed venturi. Everything else needs to be correct first before increasing the pilot though, b/c just a small amount of blockage in those "bypass ports" will cause a lean bog, along with too high of pop-off, etc.
You can try opening up the idle mixture screws to add more fuel but at the potential expense of making the idle too rich. The pilots don't control idle mixture, so going up one size on the pilots won't have any effect on the idle screw position. It's a better design on the top end IMO, with the high speed mix screw, the screw is supplementary to the high speed jet so in that case you can compensate by opening the screw if the high speed jet is a bit too small. I think Mikuni needed a way to get an emulsion to the the idle port, so the natural solution was to feed the idle circuit through the pilot circuit (A really cool idea as opposed to a separate air feed, but I think this causes confusion).
So anyway, it's not a good idea just to blindly increase pilot size without confirming all the other parameters first, could just be gum in one of the "bypass holes" causing a mid-range bog. The carbs have to come off and apart in order to confirm everything anyway, so starting from scratch they have to come off at least twice before I'd break down and increase pilot size unless someone before me had documented their experience. Your ski isn't my boat, different carbs and engine, so all I can tell ya is what I found in my case which may or may not apply.
You can try opening up the idle mixture screws to add more fuel but at the potential expense of making the idle too rich. The pilots don't control idle mixture, so going up one size on the pilots won't have any effect on the idle screw position. It's a better design on the top end IMO, with the high speed mix screw, the screw is supplementary to the high speed jet so in that case you can compensate by opening the screw if the high speed jet is a bit too small. I think Mikuni needed a way to get an emulsion to the the idle port, so the natural solution was to feed the idle circuit through the pilot circuit (A really cool idea as opposed to a separate air feed, but I think this causes confusion).
So anyway, it's not a good idea just to blindly increase pilot size without confirming all the other parameters first, could just be gum in one of the "bypass holes" causing a mid-range bog. The carbs have to come off and apart in order to confirm everything anyway, so starting from scratch they have to come off at least twice before I'd break down and increase pilot size unless someone before me had documented their experience. Your ski isn't my boat, different carbs and engine, so all I can tell ya is what I found in my case which may or may not apply.
Thx I appreciate that good info. I'm satisfied the carbs in there entirety are clean. I have good shop air and I fine combed it. The only thing I didn't do was replaces the diaphrams etc which could be leaking who knows. I'm going to let the machine go back to my brother in law as is for now, there's a fairly large bill already in parts (my labor was free). So he can ride it and get some use out of it. The plugs look great I'm confident there's no lean condition bad enough to hurt the engine. When I get a round 2 at the machine I will go over the carbs once more with proper kits, then look into what pilots are in there.
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