After installing driveshaft.

[HoverRL]

I recently had my 2005 GTX motor rebuilt due to a dropped valve. Install went well and driveshaft alignment seemed cool as I ran the machine while on the trailer while backed into the water; no cavitation or vibration. Next I attempted to back the machine off the trailer and something let loose in the drivetrain allowing the engine to free spool. Stopped the engine and started again in forward, everything seemed fine, until I attempted to back off again with the same results. What Gives? Anyone?

[Seadoodoc]

Free rev out of water is usually leak causing super lean condition. Likely cause of first failure. Check twin pulse fitting on case under carbs. Also restricted fuel supply from bad lines and clogged internal filters. If it free revs again, pull lanyard and pull throttle WOT to kill it to avoid damage.

[Seadoodoc]

Is that 2 stroke?

[HoverRL]

I appreciate your response but you may have misunderstood the issue. The motor and control of it are fine it runs good. The issue is that somehow the powertrain i.e.: driveshaft disconnects from either the engine or pump. It seems to work fine until high RPM and then a whining noise and loss of propulsion from the Pump.

[BigDfromTN]

Just a stab in the dark here.... Cavitation. May something to do with trailer or debris at ramp???

[eb87]

I think you already know what your issue is, if it's "disconnecting" something is not installed properly, engine too far forward, driveshaft not fully locked on the rear belows bearing, pump not fully seated. I would see how much play is in the driveshaft first.

[HoverRL]

I appreciate all of your points, I will recheck all of them although everything seems to be in order. The Pump is definitely seated and it would be difficult to get the engine too forward. I used the previously installed driveshaft! I am stumped! What does "driveshaft not fully locked on the rear bellows bearing" mean exactly? The Circ Clip is installed correctly in the Floating Ring.

[jpt7779]

Engine to pump alignment entails left, right, up, down, and forward and aft. SeaDoo calls forward and aft the "longitudinal axis". How much play do you have in drive shaft movement fore and aft? Have you check both ends of the drive shaft and the impeller for stripped splines?

[HoverRL]

In researching alignment (driveshaft) I have been unable to find any documentation defining "longitudinal axis". Can you provide your link?

[jpt7779]

This is from a 2011 Shop Manual which is not going to help you a whole lot, but does explain the same concept. That is why I asked you how much play you have in the drive shaft fore and aft.

On your ski approximately 3/16-1/4" play is all you should have to apply the proper pressure on the floating ring carbon seal-bellows AND ensure the splines are far enough into the PTO housing and impeller.

Bottom line is you do not want the engine too far forward, which will cause a poor carbon ring seal and potentially not have the splines engaged properly.

Make sense?