No propulsion. Impeller coupler issue?

SuperJet-Dave · Jul 8, 2018

Was riding and all the sudden the motor would rev with the throttle, although no propulsion, and just an ugly whirling sound of sorts. I can move the motor flange coupling by hand, and everything inside the hull spins fine. I can hold the impeller shaft still while the motor flange moves, and visa versa. I assume there is some coupling connecting the impeller shaft to the motor flange that is messed up. Although, I cannot seem to decipher what it is from the Superjet 2004 diagrams (see below). Any suggestions where to start?

surfjunkie · Jul 8, 2018

i stripped my shaft yesterday at the beach. sounded exactly like you describe. usually drive sahft and short shaft take a poop together. i feel your pain

SRQski · Jul 8, 2018

#12 in first pic (driveshaft) slides inside #3 in second pic (midshaft) and they mate up via splines - which from your description sounds like they stripped. That's the coupling your talking/asking about, can't really see it from the pics and you don't see it looking inside your ski - what you can see is the midshaft, the driveshaft slides up inside it.
Pull the pump and you'll likely see stripped spines on the end of driveshaft.
Bummer - but it happens...

Sent from my LG-H700 using Tapatalk

SuperJet-Dave · Jul 8, 2018

surfjunkie said:
i stripped my shaft yesterday at the beach. sounded exactly like you describe. usually drive sahft and short shaft take a poop together. i feel your pain

Thanks. Ugh. Bad day for shafts ;-(

SuperJet-Dave · Jul 8, 2018

SRQski said:
#12 in first pic (driveshaft) slides inside #3 in second pic (midshaft) and they mate up via splines - which from your description sounds like they stripped. That's the coupling your talking/asking about, can't really see it from the pics and you don't see it looking inside your ski - what you can see is the midshaft, the driveshaft slides up inside it.
Pull the pump and you'll likely see stripped spines on the end of driveshaft.
Bummer - but it happens...

Sent from my LG-H700 using Tapatalk

Ah. Ok. Thanks for explaining what the diagram didn’t show! Will pull the pump off when I get back home (Of course this happened while on vacation and no good way to work on it).

SuperJet-Dave · Jul 11, 2018

The pics below are the end of the drive shaft. Since this is my first time pulling the pump/shaft, I am guessing the spline is stripped and not useable/fixable... and the the shaft (& impeller?) needs replacing. Also assume that I need to pull the mating coupler shaft and replace as well. Does this come out without moving the motor? Or do I need to move the motor forward to replace this?
Any help/ guidance is appreciated. Arrrg

newbee · Jul 11, 2018

yep time for a new one. Should do a midshaft also

surfjunkie · Jul 11, 2018

u have to at least pull the motor far enough forward to be able to un connect the couplers so u can remove the midshaft.

if u want to practice u can come do mine and i'll supervise your progress

SuperJet-Dave · Jul 11, 2018

newbee said:
yep time for a new one. Should do a midshaft also

Thanks ;-(

SuperJet-Dave · Jul 11, 2018

surfjunkie said:
u have to at least pull the motor far enough forward to be able to un connect the couplers so u can remove the midshaft.

if u want to practice u can come do mine and i'll supervise your progress

Sounds right. Looks like I have an expensive project with lots of labor. Man these skis can be a pain. Too bad they are way too much fun.
I think doing this once will be more than enough fun ;-(
Good luck with yours