Texasmark
Supreme Mariner
- Joined
- Dec 20, 2005
- Messages
- 14,795
Got the new prop Monday and took her for a spin yesterday.<br /><br />Had a 13 1/8 x 21 Ballistic on a very light 17' padded alum bass boat.<br /><br />Ran 49 in 50 degree water, dry air. Rpm's were too high at 6250 ('02 Merc 90, 2.3 gears).<br /><br />Installed the 13 1/2 x 24 Ballistic I just got from iboats. Had to notch the trim tab to get her to clear. Took her out for a spin yesterday.<br /><br />Water was 56, air dry; about like the last time I was out. The prop did as it was supposed to: Rpm's dropped nicely to 5600 (5500 recommended upper limit) and speed went up 3 to 52. <br /><br />Turns were good; a little cavitation in a hard turn with it trimed where it was when running, rpm's up about 400, but a couple of seconds after straightening out, it cleared out the bubbles and dropped back to 5600. I'm a happy camper......on that part.<br /><br />But now I now I have something funny going on. When I am at idle and in gear I hear this intermittent growling (rumbling....definitely mechanical) noise coming from the engine area. <br /><br />If I give her a tad of throttle it quits and I don't hear it again all the way to WOT and back till I cut the throttle just before it comes out of gear going to N.<br /><br />Soon as I go to N it immediately stops and restarts going back in gear. Going back and forth, sometimes it does it and sometimes it doesn't.<br /><br />At first I thought the hub might be slipping (wondering how I got the prop for $154 including shipping.....maybe something wrong???) as I heard it initially leaving the launching ramp. I stopped, tilted up the engine and checked everything. Prop was correctly installed.<br /><br />But you can't turn the numbers I did with a slipping hub and it would surely slip at WOT before it would at idle. So it must be something else.....maybe something to do with the pitch being 24". Maybe the shaft is moving back and forth due to the water turbulence and I don't have enough rpm's to push the shaft all he way in and stay there....getting ahead of the story.<br /><br />The prop is installed exactly as the other one was (which didn't make any noise) same thrust washer, same nut and locking key, same 55# torque. Splines seemed to mesh correctly. Spun it by hand and it is smooth as silk.<br /><br />You can however push in on the prop and it will move forward (toward the gearbox) about 1/8 inch in N....prop shaft and all moves. Didn't try this with the other one.<br /><br />Spun the wheel while holding it pushed in and it was smooth as silk....wasn't rubbing on the housing. Didn't dismantle it yet, nor put the other back on checking for abnormalities, nor look in the manual and see if the movement of the shaft back and forth in N is normal (didn't check it in gear yet).<br /><br />So (with respect to the numbers) it's back to what the guys that know say. What you get out of your rig depends upon it. There are rules to be applied, and sometimes they work (like for me this time), but that isn't always the case. Every boat/setup is different.<br /><br />Later,<br /><br />Mark
