Strange problem...

magster65

Commander
Joined
Sep 1, 2002
Messages
2,573
The boat is a buddy's 2000 Baja Boss 232 / 496 HO / XR drive / SS mirage prop. It looked good and sounded good (still does) so he chose not to do a sea trial because the weather was horrible at the time he was looking at it. Bad news... the boat seems to slip the prop as it comes on plane. We've tried 3 and 4 blade props and various pitches but the problem is still there. Last week it seemed to get worse... he said every time the boat passed 3000 rpm the engine would just rev up like there was something slipping. So he bought a new coupler and we pulled the motor and swapped it out. The old one looked bad so we thought we had it fixed. No luck. I saw him out on Sunday and he said the boat was fine until it had run for 1/2 hour then the problem came back. I ran along side of him and it's not something silly like the leg trimming up on it's own. I'm not a drive mechanic but is there any way the cone clutch could do that? He's stumped (so am I) and totally depressed (I'm not depressed). Any thoughts?<br />I do have one other thought... a bad one... that power package was not an option in that boat. I'm wondering if the prop's not far enough in the water or something nasty like that.<br />Also can someone post a diagram of what an X-dimension measurement is and how I can find out what this boats ideal one is?<br />Thanks
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: Strange problem...

Post this over at the I/O forum you will get a lot more help.Moderator will probably move it soon anyway.You can probably get an idea where it's at by checking the antiventilation plate.Normally about even with the bottom of the boat.If it seems excessively high that may be the problem.It's interesting that it appeared to go away with the new coupler,but came back. Makes you wonder about the setup.A 496 would certainly be a special coupler did you check that you installed the correct one not just the same as the old one.I'm sure you will get more specific help at the I/O forum.
 

magster65

Commander
Joined
Sep 1, 2002
Messages
2,573
Re: Strange problem...

More info;<br />the coupler was replaced with a brand new Merc. 496 unit which are different than the lower hp ones. He's tried 2 different props with the same result so it's not a spun hub. I don't understand how it could 'come and go' either. It doesn't make sense.<br />I've got some time to stop by there today... I gotta' know what's up with this thing.
 

magster65

Commander
Joined
Sep 1, 2002
Messages
2,573
Re: Strange problem...

Hmmm, I drove by to have a little looksie at the prop. The prop looks ok but there seems to be a gap between the gear housing and the prop itself... like there's too big of spacer in there. It looks wrong.
 

Reel Poor

Vice Admiral
Joined
Jan 29, 2005
Messages
5,522
Re: Strange problem...

Magster if its blowing enough exhaust out of that crack or the outside diameter of the hub is to small letting exhaust escape over the hub it will cause that kind of problem.
 

magster65

Commander
Joined
Sep 1, 2002
Messages
2,573
Re: Strange problem...

I think that's it.<br />That gap was introducing exhaust into the prop but wouldn't slip until it reached 2500 rpm or so. I'm willing to bet the reason it was intermittent is because if he actuated the silent select to go 'through-hull' there was no (way less) exhaust in the prop.<br />It seems so simple now :rolleyes:
 

magster65

Commander
Joined
Sep 1, 2002
Messages
2,573
Re: Strange problem...

Confirmed.<br />What a dork!<br />On the weekends we meet at a bud's place for a little bench racing. We usually sit around the fire, have a few bevvies and tell a few stories. Gee, I wonder who's gonna' get it this time?<br />hehehe... the dork!<br />I'm glad it wasn't something more serious.
 

Purduebarry

Petty Officer 1st Class
Joined
Sep 29, 2005
Messages
378
Re: Strange problem...

The real dork is the guy who sold the boat and hopefully real cheap beacuse he thought the slip problem was serious.:'(
 
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