Rock 1 - 50 hp efi 4 stroke 0

[carman.d]

So after finally getting the right prop for my pontoon boat I took her out for a test this weekend - still wasn't getting the rpm I wanted but better (4800). Adjusted the throttle and picked up 200, but then - paying attention to rpms instead of the depth finder - smack!!
Big rock made the boat jump like hitting a speed bump! New prop toast. hub that's supposed to slip and protect engine - in pristine condition. Bottom leg - not so good. She slips as soon as you put any rev on (with different one piece prop so not hub slip). With motor off she spins fine in neutral, but in drive I can spin her by hand with a loud "clicking" noise in the bottom of the leg about once per turn.

So - new leg? just a broken gear or shaft replacement?
And if the whole leg, should I pop extra and put a bigfoot leg on? (20' pontoon boat)

I'll probably take her in for estimate - but if anybody wants to tell me a quick and easy way to diagnose further I might take a look myself.
2011 Mercury 50 hp 4 stroke efi (not bigfoot).
(ps - moderately handy but totally new to boat motors - so don't want to break down the whole leg and mess it up completely)

 

[jbjennings]

Re: Rock 1 - 50 hp efi 4 stroke 0

I could be wrong, but the ratcheting sound you are describing may be normal. The other prop hub may also be slipping (I've even had a bad NEW one before!). Scribe a mark across the hub and take it for a spin. See if the marks are still lined up. If not, you may just need a new prop. ALso, take the prop off and spin the propshaft by hand in neutral and see if it's bent. If so, you can likely tell it just by eye.
Don't freak out just yet...... If it's still popping out of gear with a known good prop, take it apart and check the clutch dog. If you lucked out and just chipped the clutch dog and not the gear ears, it might not be that high.
Good luck,
JBJ

 

[carman.d]

Re: Rock 1 - 50 hp efi 4 stroke 0

well I finally got it looked at (so busy with reno's). Broken motor shaft, bent prop shaft, and something about a pinion gear. OUCH - looking at $2000-$2500 to fix - good thing I have insurance, but still a $500 deductible.

 

[matth121]

Re: Rock 1 - 50 hp efi 4 stroke 0

man, i'd want to see all those parts before dropping that kind of cash. Do you trust this boat shop/mechanic? I'm sure in all likely hood they're telling the truth but everyones heard horror storys about mechanics gouging people. Best of luck.