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pb
06-03-2002, 09:59 AM
I just fired and tested my new motor this past week while on vacation. The new motor is appox. 450HP. The motor prior to the rebuild was about 330HP. The bearing was replaced about 6yrs ago and has been properly greased. While the engine was out I hand spun the shaft which spun freely with no binding or gritty feel. There was no fore or aft movement, just a very slight up/down and side to side movement of the rear of the shaft which I have been told is normal. Therefore I did not replace the bearing.
Now, while testing and tuning the motor I would hear a chirp and somtimes a short squeal that resembled an alternator belt squeal. Naturally I removed the belt and did not hear the noise. So, problem solved, I thought. I removed the belt again just to be sure and heard the chirp again.
Could the additional power added to the pump instantly hurt the bearing. What kind of sound would the bearing make if going south on me. Would it be a constant sound or at intervals. The bearing housing does not get hot after running, just a little warm to the touch. This is a JF pump and I really do not want to pull the motor again after I just got her in. Some info on this would be helpful. How about bowl bearings? I had the engine builder check the u-joints prior to re-installing them and he said they were fine. Engine alignment? I had new stringers installed so we started from scratch on the alignment which I feel is fine.
Any comments would be appreciated.
Thanks
Paul

NOMERCY
06-03-2002, 10:37 AM
PB, disconnect the drive shaft from the engine. Then try turning the pumb by hand. See if the bearings are still feel free. Next fire the engine with out it connected to the pump. (be sure to have water running to the engine from your garden hose)This way you will eliminate the engine or the pump that have the problem. Good luck with finding the problem.

Hotcrusader76
06-03-2002, 10:59 AM
I had the same symtoms on my 76' Tahiti one year. It was the pump....the bearings were gone, and water was coming in through the thrust bearing pack (what ever you call it).
I wouldn't rule out the motor quite yet either....But look at that pump first!

Hotcrusader76
06-03-2002, 11:32 AM
http://www.cpperformance.com/TechTips/trouble-shooting.htm
Check out this link. It will assist you in your troubleshooting of the Jet...Goodluck bro!

wsm9808
06-03-2002, 11:41 AM
you on the trailer, or in the water? When I first got mine it would skreech like crazy on the trailer but be fine in the water. The shaft bushing in the bowl was completey gone.

pb
06-03-2002, 12:42 PM
I was in the water idling around and sometimes it would occur under acceleration, but not all of the time. I would seem to think it would happen consistently if the bearing was going bad. I had the bowl off the previous day and the bowl bushings appeared to be fine. One thing that does occur is that all the gear oil is pushed out of the bowl. I have had the seal changed a couple of times only to have it happen again. Has been this way for 9yrs. Water pretty much ends up as the lubricater for the bowl bushings. I have a hard time believing that a bearing that was just fine last year and has been properly maintained just fails that quickly.