07-06-2008, 12:38 AM #1
RPM/Speed loss after new pump bearings.
This is a problem I have ran into on the Ultra150. Has anyone else seen a loss in rpms after rebuilding a High Output GPR pump??? It takes some time for the new bearings to loosen up but Im just curious if anyone else have seen this! I also changed the bearing and seals in the intermediate shaft at the same time.
07-06-2008, 07:14 AM #2
after rebuilding you should be able to turn both the intermediate and pump relatively freely (this way you can tell nothing is binding)
07-06-2008, 07:16 AM #3
07-06-2008, 09:29 AM #4
Im only talking about a 70-80 rpm loss here. Everything turned freely nothing was binding at all but it was somewhat "tighter" than the old bearing that had several hours on them. On the old 150's it took about 3 or 4 hours of run time for the revs to come back. I have never heard of you guys mention this but it is the same concept no matter the brand.
07-06-2008, 09:47 PM #5
I have noticed that after a rebuild the new seals cause a drag on the shaft when turned by hand. This usually goes away after run for a few hours.
I rebuilt a pump about 2 years ago, and had a rpm loss problem, but not right away. When the bearings were pressed in, they must have gotten a little off center and some very small aluminim shavings from the stator housing got into the bearing cage. Over a short period of time (maybe 4-5 hrs of run time) the boat would lose rpms when back to back passes were made.
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