96 gtx irratic rpms/misfire??

[monkeySEA then DOO]

hello new to site and love it so far!!has anyone had a similar problem w a 96 gtx 787? ski has ran great for a week after installing a new topend...put new fuel lines and clean the carbs.. it 1st started to bog down up to 3/8 throttle and ran perfect after that...so i figured it was time to clean the carbs again. but now the rpms bounce allover the place and runs terrible! cant go faster than 7-8 mph...compression is good 140-148.. ive also tried a pair of carbs off another gtx ive got and still runs the same.. i also cleaned those carbs..ive tripple checked all the fuel line connections, cleaned the petcock, all the obvious stuff.. im not to familiar w the electronics from seadoos so i was wondering if there is anything that could make it run like this?
couple random ???? the black fuel vent that attaches to the hull-mine doesnt allow air either way...is this normal?
the needle in carb-it has a small hole in it; does it matter which way it goes?
please help!!!
thanx for your time!!!

 

[Seadoobuddy]

Hi & Welcome to the forum.
Where about are you in Michigan, lots of us here through out the state.
I'm not a carb guy but if Dr Honda see this he will steer you in the right path.....along with a many other experts here.
Just stay tuned for a day or so.

 

[monkeySEA then DOO]

well just tried the 3rd set of god carbs and same thing...anyone know what the volts at the plug caps should be?how do i test the rectifier?

 

[mtrainer]

Can you try a fuel pump off one of those other skis?

 

[monkeySEA then DOO]

fuel pump is on the carbs...

 

[purple_people_eater]

the "fuel pumps" on these are built into the carbs. first take the boots off the wires and cut about 1/4 inch off and reattach the boots. see if that helps. are you getting a "voltage low" signal on your multi gauge?

 

[mtrainer]

Sorry I was thinking of something else. Have you cleaned the fuel filter?

 

[Strizzo]

erratic misfire sounds like it could be a bad rectifier. unhook the red wire and see if the problem clears up.

 

[monkeySEA then DOO]

yeah starts and ran great withot red wire hooked up.. but rpm guage bounces all over and as soon as i get up on plane it dies everytime? i also swapt out for a good rectifier and it still hesitates. and also swapt out the whole black box in back...the only other thing it could b is the mpem ;ive got a 97 gtz for part but doesnt have a cdi; could i still swapt mpem? ...could this make it run like this? open to ideas!!!!

 

[Strizzo]

have you clipped back your plug wires? they can corrode inside the boot and cause weak spark issues.

 

[monkeySEA then DOO]

tried another set of coils and same thing..im thinkin possibly cdi?

 

[1stdoo]

I know its a late response. I went threw the same issues a few years ago. I turned out to be a bad stator even though the stator test okay wich they will do.