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rob935
04-08-2008, 01:25 PM
hi guys i have a 93 prostar with a velvet drive, i seem to have a slight knocking noise coming from the prop/shaft at low revs normally when docking ...i have the boat on my driveway and spun the shaft but all seems ok apart from what seems to be some friction at the t piece holding the shaft under the boat just before the prop.

is there a way of lubricating this section of the shaft ??

rob935
04-08-2008, 01:25 PM
hi guys i have a 93 prostar with a velvet drive, i seem to have a slight knocking noise coming from the prop/shaft at low revs normally when docking ...i have the boat on my driveway and spun the shaft but all seems ok apart from what seems to be some friction at the t piece holding the shaft under the boat just before the prop.

is there a way of lubricating this section of the shaft ??

BrianM
04-08-2008, 01:46 PM
Are you absolutely positive it is coming from the shaft? Many times a knock while idleing is actually the damper plate between the engine and transmission. Does it go away in gear?

Monte
04-08-2008, 01:47 PM
I may get blasted for this one, but the knocking sound at low RPM's is normal from what I have been told..

I don't know anything about the lubricating question but would be interested in knowing myself..

Jayc
04-08-2008, 02:45 PM
I was told it's the damper plate on my old boat. Used to do it in gear at around 500rpm when the engine was cold. Once warm and rpm had bumped up to 650-700rpm it went away.

Was like that for around 1000hrs without any issues.

etakk7
04-08-2008, 04:07 PM
I had a similar noise last summer and even brought my boat to the dealership to have them look at the tranny. They couldn't figure it out, and I realized later the prop was loose. I would make sure it isn't something simple like that.

etakk7
04-08-2008, 04:07 PM
duplicate message

Ryan
04-08-2008, 04:43 PM
If it's not the damper plate, it could be the strut bushing (aka cutlass bearing). $55 fix from skidim.com.

jimmer2880
04-08-2008, 07:21 PM
.....
is there a way of lubricating this section of the shaft ??

The "bushings" on the strut (what the shaft passes through) are rubber with groves cut into them. The groves allow water to pass through, thereby lubricating and cooling your shaft.

To answer your question directly - no, you do not need to lubricate that section of shaft.

Chas
04-08-2008, 07:25 PM
I had a bad knock in my shaft - it turned out that the engine and shaft were way out of alignment and the front end of the shaft was damaged. I ordered a new shaft with the dual taper, a new coupler, and as soon as I figure out how to get the stupid screw jack motor mounts to go up and down, I should be good.

In my case, the thump was the front coupler walking on the shaft. It ate it up pretty badly - it looks like it may have been welded up once before. That leads me to believe that somebody had the same problem before, but didn't align the drive train.

It only take a few moments to undo the four bolts on the coupler and check the alignment.

rob935
04-09-2008, 01:33 PM
thanks guys plenty of food for thought there , it only happens when in gear at very low revs !!! i dont have any problems at all going in or out of gear ,and it runs perfect . i have checked the damper plate and couplings and all seem fine ,

ORX-1
04-09-2008, 03:52 PM
thanks guys plenty of food for thought there , it only happens when in gear at very low revs !!! i dont have any problems at all going in or out of gear ,and it runs perfect . i have checked the damper plate and couplings and all seem fine ,

I have an 06 x-1 and bought it with .05 hours on it. That noise has been there since day one! I took it in and they replaced the shaft, and it is still there. I haven't paid attention lately but I am sure it's still there. Drives me nuts. Please let me know if you figure it out! I don't think the dealer wants to keep trying so if I have an idea I will pass it on to them. Good luck!

VOLFAN
04-09-2008, 08:52 PM
I have a 03' X2 and I had a knocking noise coming from the shaft / popeller area. I went out and looked at it today and found the prop was loose. I tightened the nut that holds the prop on and that cured the problem from what I can tell. I was lucky on that if that is the case.

rob935
04-10-2008, 04:47 PM
ok will double check the prop so , thanks guys.

gguppy
10-01-2008, 08:39 PM
I have the same notice plus a water leak i think the bushing is woren out where the shaft goes threw under the boat

TMCNo1
10-01-2008, 08:56 PM
I have the same notice plus a water leak i think the bushing is woren out where the shaft goes threw under the boat


You don't have a bushing where the shaft goes thru the hull, you have a stuffing box/shaft log and tightening and repacking is covered here, http://easttxskier.com/stuffingbox.html and here, http://www.mastercraft.com/teamtalk/showpost.php?p=503319&postcount=52.
That is, if you don't have a dripless shaft log that was a aftermarket install on your '92.

bwilson
10-01-2008, 09:52 PM
I have that knock when it is in gear (FWD) at low revs, I consider it normal.

gguppy
10-02-2008, 07:56 PM
that sounds like it will fix my water leak. but the strut where the shaft goes threw is off center that where i think the knock notice is coming from. Is there a bushing in there?

TMCNo1
10-02-2008, 09:08 PM
that sounds like it will fix my water leak. but the strut where the shaft goes threw is off center that where i think the knock notice is coming from. Is there a bushing in there?

There shouldn't be.

EricB
10-03-2008, 03:22 PM
How did you check your Dampner Plate? Did you take the trans out and inspect, because that's the only way to tell.
Operate the boat at an idle in gear with the engine cover open. Use a mechanic's stethescope (or plastic tube or metal rod) and attempt to isolate the noise.
If the boat has some hours on it and if it only does it at low idle speeds (500/550 rpm) and goes away at higher RPM's you can bet that most likely it is a dampener plate. That is, of course, assuming you have checked that the prop is tight.

brucemac
10-03-2008, 03:27 PM
hey question on this. does the "knock" sound similar to the one in reverse?

i swear i never had it in forward until i upgraded my prop, but have now noticed it at times in gear at forward idle. to me, it's almost more like a "growl". but i could see how some could call it a "knock".

i had my shaft aligned mid season, so i know i'm good there and boat continues to run terrific. seems like nothing to worry about, but wanted to get some clarification of the sound.

gguppy
10-05-2008, 08:06 AM
thanks, i will check the prop first. The boat has 348hrs and 92 prostar 205 351HO

ncgreg
10-25-2008, 08:15 AM
I experienced the same knock in my 93 prostar w 351 HO. At the same time, noticed the motor was struggling to idle when warmed up, along with the nock. In my case, I found that the idle mixture needle valves on the holey 4010 carb some how got out of sync, and when I readjusted them, the nock disappeared. Nice cheep fix.
Good luck.

93Prostar190
10-25-2008, 12:25 PM
I had a 93 PS 190 with the the 351 HO ... great boat .... you know if you feel good about the shaft, etc ... could the noise be from the swim platform? Mine used to knock around a little bit (it depended alot on the loading of the boat with fuel and passengers etc ..... the platform would move a little bit up and down from the play in the lock pins and that resulted in a knocking sound ... it used to happen mostly at idle and at reverse .... give the platform a little shake and see if it sounds the same .... you may be able to have someone hold the platform and see if the problem goes away ... just a little theory ....

good luck and great boat!