Hey guys, I have a 96 Mariner Magnum EFI 2.5L, serial # is OG337303. I did a tune up on it this weekend. New fuel filter, inline oil filter, plugs and impeller rebuild kit. I fired it up in the driveway with the muffs to make sure everything was good. I noticed whenever I put it in gear, either fwrd or reverse the prop won't spin. The boat does have a hot foot. I have to rev it considerably to get the prop to spin. This is the first time I start it in the driveway but I know before when on the water just putting it in gear it would cruise about 3.5mph. So that means something's not right.... right? Any suggestions before i have to tear it back down? Not sure what I'm missing here.

If I had to guess, I'd drop the lower unit and check to be sure it was re-installed correctly.

Sounds like a linkage issue. The throttle and shift linkages all are connected and need to be adjusted to work properly. I have this same engine and its easy to not get the shift rod all the way in place when installing the lower. I don't have a hot foot so your setup is a little different. Get a buddy or wife to move the controls while you watch the linkages and see what's happening, it will probably be easy to spot with a helper.

But if the linkage wasn't right would it still spin when i gas it? 

47 minutes ago, DINK WHISPERER said:

But if the linkage wasn't right would it still spin when i gas it? 

If the linkage isn't right - gears won't fully engage.  

I didn't think there was an "incorrect" way to put it back though? It all lined up when going back in. And like i said, it will soon when i gas it. Guess I'm going to have to go back in! ?

One second...I took pictures of my manual for this motor...let me post them....it may help you.

 

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I have a 96 Mariner 175hp.  This is out of the Clymer manual.  

Thanks for those pics! That will help for sure. 

Glad to help man 

Any chance it's just a spun prop?

54 minutes ago, VolFan said:

Any chance it's just a spun prop?

Doubt it, it was working perfectly before tune up.

Sounds like you didn't align it correctly when reinstalling. 

14 minutes ago, iabass8 said:

Sounds like you didn't align it correctly when reinstalling. 

That's what everyone has told me so far. Just don't understand why prop does spin if i gas it up? Wouldn't it not spin at all if misaligned? And i have to wait too Saturday afternoon to get back to this too. It's killing me! 

Your throttle and shift leakage are connected under the cowl. Adjusted to far one way and it grinds going in because its throttlds to high, adjusted the other way and it does what yours is doing. Sorry hard to explain. Like i said if you get a helper to work the controls while you watch all the linkages from different angles it will probably be obvious to you

Yeah guess I'll have to wait for the weekend to check it out again cuz I'm a bit confused. Mine did grind when putting it in gear before I took it apart. Now it's too South like you can't even feel the gear catching. Now I'll miss fishing this weekend working on this again! 

Thank you again to everyone who helped out with this. The lower unit shifter was not in at all. I can't believe I missed that after doing this so many times. 

The prop will spin whenever in gear with the engine running at any rpm.

Try engaging the gears without the engine running, make sure the ignition is off and try turning the prop by hand, it will not turn without turning the crank shaft.

My guess is the drive shaft splines are not aligned and engage properly.

Tom