Tweet
This past weekend I took the jetski out to the lake. This was the second outing of the season for the ski. It was a short outing.
Shortly after leaving the pier while cruising at around 35mph, I crossed a slight swell. The ski lost drive and started running very rough.
After some on the water checking, it appeared that one cylinder was not running and the driveshaft was not restrained in the pump area.
I waited for tow from a buddy on his ski. Once the ski was on the trailer, I was able to look into the intake grate. At that time I noticed the driveshaft was twisted into two pieces just in front of the impeller connector.
So the ski went home, at which time I took the pump off. I noticed several things:
1. The wear ring was missing chunks of the lining material, even though the impeller was still undamaged and seem to spin normally on its bearing.
2. The driveshaft was showing considerable pitting.
3. Forward of the pump, in the shoe area, there was some damage to the plastic that looked like cavitation pitting.
The impeller and wear ring are one season old. They were installed over the last winter lay-up.
Questions:
1. Would severe cavitation cause the type of damage that is evident to the lining of the wear ring?
2. The small sealing ring at the top of the wear ring did not appear to seat evenly. This may have allowed for much more cavitation. Is this possible?
3. Is a driveshaft failure of this type normal? I do not have the full driveshaft removed from the ski yet to obtain a full pic.
http://webpages.charter.net/leitht/PumpDamage1.JPG
http://webpages.charter.net/leitht/PumpDamage2.JPG
I have read the forum posts regarding the sealing of the ride plate and the shoe. I will check these, but at this time I am more suspect of the poor seal of the wear ring.
I am curious if I should be looking for something substantial that could have caused this damage. I plan to replace the driveshaft and the wear. Reinstall the pump making sure that it seal properly and look at the shoe seal.
Any other suggestions?
Thanks in advance... Tim
Shortly after leaving the pier while cruising at around 35mph, I crossed a slight swell. The ski lost drive and started running very rough.
After some on the water checking, it appeared that one cylinder was not running and the driveshaft was not restrained in the pump area.
I waited for tow from a buddy on his ski. Once the ski was on the trailer, I was able to look into the intake grate. At that time I noticed the driveshaft was twisted into two pieces just in front of the impeller connector.
So the ski went home, at which time I took the pump off. I noticed several things:
1. The wear ring was missing chunks of the lining material, even though the impeller was still undamaged and seem to spin normally on its bearing.
2. The driveshaft was showing considerable pitting.
3. Forward of the pump, in the shoe area, there was some damage to the plastic that looked like cavitation pitting.
The impeller and wear ring are one season old. They were installed over the last winter lay-up.
Questions:
1. Would severe cavitation cause the type of damage that is evident to the lining of the wear ring?
2. The small sealing ring at the top of the wear ring did not appear to seat evenly. This may have allowed for much more cavitation. Is this possible?
3. Is a driveshaft failure of this type normal? I do not have the full driveshaft removed from the ski yet to obtain a full pic.
http://webpages.charter.net/leitht/PumpDamage1.JPG
http://webpages.charter.net/leitht/PumpDamage2.JPG
I have read the forum posts regarding the sealing of the ride plate and the shoe. I will check these, but at this time I am more suspect of the poor seal of the wear ring.
I am curious if I should be looking for something substantial that could have caused this damage. I plan to replace the driveshaft and the wear. Reinstall the pump making sure that it seal properly and look at the shoe seal.
Any other suggestions?
Thanks in advance... Tim
Comment