superjet full throttle problem

bobob729

bobob729

Location
wichita, ks
I have a 96 superjet 61x motor with a coffmans exhaust and a sbn44, and a pitch prop. I have great lowend but when i get in it for a second it falls flat on its face like its flooding out i have done the high speed all the way in and worked it all the way out. It has gotten no where and does the exact same thing. When it cuts out and dies i can get back into it if i let off for a second then get back in on low end. I just bought the ski from missouri and now its in wichita ks, any help is worth it. Some one told me to check the pop off and i will do that tonight, My ski runs great on bottom end though so if i can get some help some one help me out right now i have a high jet of 140. thanks for the help
 
tom21

tom21

havin fun
Location
clearwater FL
make sure the check valve is good and seals by holding a finger over the hole on the flap side and blow into the flap and then suck back. if it lets air thru backwards its crap. I just found one that had some crud growing under the screw and plate but looked spotless everywhere you could see and it lifted it just slightly. was causing the skis power to come and go at higher speeds. its always the little things that get ya.
 
bobob729

bobob729

Location
wichita, ks
replaced check valve the other day changed the high jet to a 135 and seems to runs alot better but it hits revlimiter like crazy when you hit full throttle is that supposed to be like that it has a stock cdi and waveblaster pipe. My 650 kawi doest ever hit revlimter about that so i figured i would ask and see if that sounds right or not. but on a positive note it doesnt die out anymore it stays running all the time now. anyhelp would be appreciated.
 
SUPERTUNE

SUPERTUNE

Race Gas Rules
Location
Clearwater Fl.
Yes, You will hit the stock rev limiter with a stock Yamaha 701 CDI and pipe/decent prop. If I remember the stock super jet rev limiter is set @ 7050 rpm, with modified ski you can turn 7100-7200 rpm's.
The Kawasaki's start retarding the timing a lot so the ski doesn't rev high and the limiter is set like 8000. They won't hit the limiter because power loss from the CDI backing all of the timing out.
 
bobob729

bobob729

Location
wichita, ks
well i got compression checked today and it ended up being 173 and 175 in back on stock head pretty good but he told me part of my problem might be that i need to run a little higher octane im running 91 already and change the plugs to a br9es. im running 8's. Still have the problem i took it out today and it got worse it went from running good at the start for a second then it will cut out and die unless i hold the throttle at a little over ittel i hardly mad it back to shore it seemed to get even worse
 
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ryan

ryan

Location
baldwin ny
who ever told you that hasnt a clue what there talking about.175 is pump gas safe 91 is fine. i am runnig 215 on pump gas.
what pipe do you have? got a pic of the motor ?
 
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Big Kahuna

Big Kahuna

Administrator
Location
Tuscaloosa, AL
bobob729 said:
I have a 96 superjet 61x motor with a coffmans exhaust and a sbn44, and a pitch prop. I have great lowend but when i get in it for a second it falls flat on its face like its flooding out i have done the high speed all the way in and worked it all the way out. It has gotten no where and does the exact same thing. When it cuts out and dies i can get back into it if i let off for a second then get back in on low end. I just bought the ski from missouri and now its in wichita ks, any help is worth it. Some one told me to check the pop off and i will do that tonight, My ski runs great on bottom end though so if i can get some help some one help me out right now i have a high jet of 140. thanks for the help
Click to expand...

If you have good bottom end then popoff is not the problem. Listen to Supertune...................

You are either hitting the rev limiter or you have fuel delivery issues.
 
bobob729

bobob729

Location
wichita, ks
well come to find out pretty sure its my cdi... i changed the main jet to a 130 and and finally leaned out but when i turn the adjustment again it did the same thing so it something wrong in the cdi im pretty sure my self so guess were looking for a cdi now....
 
Y

yamaha909

Location
las vegas,nv
Dude,if you have a single 44 you need a 120 pilot and a 145 main jet.1.5 N/S and a 95 spring.Set your low speed adjuster to 2 1/2 turns out and your high speed to 1 1/2 turns out .Try that before you go changing Cdi's etc.
If your ski is dying like that it needs more fuel,not less.
 
fast superjet chase

fast superjet chase

Location
Colorado
mine did the same thing last year and my coil was bad ran great on the low end soon as the rpm's raised started acting like i was hit the rev limiter. so went through all the same stuff then tested my coil it was bad threw a new on in it and ran like a champ. so if i were you id test both coil and the cdi.
 
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