View Full Version : Drive Train Whine at 1100 RPM - 2004 MC Prostar 197
BarefootWt
01-25-2005, 10:23 PM
My MC whines a little at 1100 RPM only (not 1000 or 1200 RPMs). I have heard from one ski school expert that this may be due to the shaft packing being too tight. I have also heard this could be caused from a glazed packing. My boat has 450 hrs on it and was used at a ski school for 3 months. The MC Dealer says don't worry because the transmissions are tough. I agree with this, but do not think the noise is in the tranny. Any thoughts or suggestions on how to make the noise go away would be appreciated.
Remove the packing and see if it is glazed. It's not hard to do and if it is, replace it. Then, the nut needs to be tightened till it drips about 2 drops every 5 seconds. If it's too tight, you'll have the same problem again. If that's not the cause of the noise, it could be the strut bearings. See if they have any play when the boat is off of the trailer. Any noticeable gap around the shaft is a bit too much. There are grooves in the bearing, so don't mistake the grooves for an excessive gap.
André
01-25-2005, 11:13 PM
Is that boat under warranty?
I would insist that the dealer take care of it...
Evan Jones
01-26-2005, 08:23 AM
After I replaced the factory prop with a 4 blade stainless, I had a whine/whistle/resonance at one spot in the RPM range similar to yours.
SD190EVO
01-26-2005, 09:42 AM
This is a stretch but I'll throw it out there.
When my boat was new the motor box would creep back and allow the big stainless bolt (that latched the top part of the two piece motor box) to just barely touch the water pump pully. It would whine like a turbo or a blower. Maybe something like that?
dsoby
01-26-2005, 01:18 PM
Aren't thier issues with the fluid making for a noisy transmission for that year? Check the mymastercraft.com forum. I remember something about folks switching over to 30W oil to solve this.
BarefootWt
08-15-2005, 11:27 PM
The root cause of the whine at 1100 RPM was the prop. The ski school I bought the boat from ran a 13.7 * 15.5 4-blade to get started and up to speed quickly as the entrance to their slalom course was close to the dock. I just switched to the factory 13.7 * 17 4-blade and the whine disappeared, the wake flattened a bit, I lost about 2 MPH top end, and the boat became much quieter. Granted, the quick pulling power went down a little, but I have a power slot anyhow so no big deal. I am hoping the fuel efficiency will improve as well. I am in the mile high city so if you are in lower elevation your results may vary.