- Location
- Houston Texas
Hey everyone! Need some advice with the latest trouble that's been plaguing me all season on my 1991 SuperJet 650.
Here is the backstory.
The ski got taken out on the lake for for the first time of the year and it ran pretty good overall, but it seemed to sputter between 1/8th and 1/2 throttle when cruising. Figured it was not much of a issue so I kept riding it thinking maybe it was in my head. The next tank of gas it started to feel down on power once it warmed up and then it started loosing RPM's if you pin the throttle for more than 10 seconds and eventually it would cut out.
I figured this was concerning so I immediately did a compression test and found that both cylinders were at 150 psi. So I then turned to putting new spark plugs in it and full Carb rebuild/cleaning of which everything inside looked pretty good. I ended up replacing everything except the needle and seat and reset everything to the the factory settings (which was the same settings it ran great on for the past few seasons and was set at prior to rebuild)
1.5 Needle & Seat
115 gram spring (44 psi pop off)
115 HS jet,
120 LS jet,
both the HS and LS Screws are turned out 1 1/8 from closed
Just took it out to see if this fixed it and the problem is still there. As before it runs awesome and pulls hard for the first 10 minutes until everything fully warmed up but then starts to cut power when you hold full throttle for more than 10 seconds.
I've also checked all my fuel lines, tank vent, and reeds and everything all checks out. I feel like it may be the something when the electronics, such as when the ignition coil gets hot after a few minutes of riding?
Looking to see if anyone has any suggestions? I've checked the resistance on all the electronics and they check out except the orange and black wires on the primary coil. Of which tested at .3 ohms when manual says they should test at 0.092 ohms?
Thanks!
Some more info on my ski if that helps:
Stock 650 engine with stock exhaust
TDR waterbox
MSD Enhancer CDI (about ~ 4 years old?)
Solas Impeller
Here is the backstory.
The ski got taken out on the lake for for the first time of the year and it ran pretty good overall, but it seemed to sputter between 1/8th and 1/2 throttle when cruising. Figured it was not much of a issue so I kept riding it thinking maybe it was in my head. The next tank of gas it started to feel down on power once it warmed up and then it started loosing RPM's if you pin the throttle for more than 10 seconds and eventually it would cut out.
I figured this was concerning so I immediately did a compression test and found that both cylinders were at 150 psi. So I then turned to putting new spark plugs in it and full Carb rebuild/cleaning of which everything inside looked pretty good. I ended up replacing everything except the needle and seat and reset everything to the the factory settings (which was the same settings it ran great on for the past few seasons and was set at prior to rebuild)
1.5 Needle & Seat
115 gram spring (44 psi pop off)
115 HS jet,
120 LS jet,
both the HS and LS Screws are turned out 1 1/8 from closed
Just took it out to see if this fixed it and the problem is still there. As before it runs awesome and pulls hard for the first 10 minutes until everything fully warmed up but then starts to cut power when you hold full throttle for more than 10 seconds.
I've also checked all my fuel lines, tank vent, and reeds and everything all checks out. I feel like it may be the something when the electronics, such as when the ignition coil gets hot after a few minutes of riding?
Looking to see if anyone has any suggestions? I've checked the resistance on all the electronics and they check out except the orange and black wires on the primary coil. Of which tested at .3 ohms when manual says they should test at 0.092 ohms?
Thanks!
Some more info on my ski if that helps:
Stock 650 engine with stock exhaust
TDR waterbox
MSD Enhancer CDI (about ~ 4 years old?)
Solas Impeller
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