150 optimax........alternator bolt snapping

[Ynot]

ok guys ........how many of you have heard of this problem.I found the alternator bolt snapped off doing the winter storing thing last fall. Replaced it then ......and now with 10 hrs on it another broken bolt ! Please need help....a friend had the same problem .......and they had to replace the powerhead due to the casting on the block that broke instead of the bolt.....

[Captn C]

I've had three break on my 1999 150hp OptiMax, but I have not had one break all last summer. The guy who finally fixed it said the bolt was not properly torqued. I was breaking it about every 10 hours until he repaired it. I put about 150 hours on the last bolt. I even bought a bolt that I carry in just case, so far I have not needed it.

[Ynot]

Capt C

Thanks for the response, I also bought 3 extra bolts. I run twin 150's on the 25'and figured that I should have them on hand. The tuff part is getting the broken part out of the mounting ear bracket on the engine block.I found
that when the bolt is tighten down all the way there was play in the alternator. The bolt snaped off right at the shoulder on the bolt, that happened twice. I have since added a very thin stainlees fender washer to take the play out of the alternator. Only 3 hours on the engine and still holding. Time tells all......keeping my fingers crossed.

[Captn C]

Ynot,
Be sure to put a little anti-seize on the threads too. The replaced the piece that hold the alternator too when they solved that problem.

Which boat do you have? SeaCraft? What year?

I have a 25' SeaCraft with twin 150 OptiMax.

[Ynot]

Cap

The boats a 2001 25' Sea Craft twin 150 Opti's Ice Blue hull.........she's a pretty boat. Bought it new in Florida from Bass pro.....and hauled it back to jersey. Been reworking lots of stuff ....changed saltwater wash down pump,added a macerator pump for the front fish box and plumbed it, built a fold down shelf in the console, battery charger,cut a hatch in the front deck for 600' of anchor line, through bolted eye hook so I can put my 162 qt cooler on the rear deck behind the transome wall and even made drink holders out of corian mounted on the side of the console, added 6 rod holders flush mounted, installed gas pistons on all the hatches, replaced all the hatch locks to stainless from plastic...they were given to me by seacraft.
And the beat goes on.....

[Captn C]

Ynot,

Have you seen the problems I have had with mine?

Do you have transom savers on your boat?

If you push up and down on the back of your T-Top does it cause the entire deck to move and the console?

Look under your gunnels and see if you have a one inch lip around the top of the deck cap that the rub rail screws go though. What I am calling the deck cap could also be called the inner liner.

[muddywater]

Just a long shot, but I had a similar problem on my tractor. The alternator bearings were shot which put such a strain on it that 2 of the mounting bolts broke.
-Muddy

[oliviergomez]

hello, i am located in europe and I have the same problem with my mercury 135 1999.. i am still struggling to fix this ongoing bolt issue. Did you finally manage to fix it properly. help please ;-)

[SECF3114M73J]

I'm not sure what the fix is, but that was a problem that has been solved. I have a 2005 225 Opti and that has never happened. I'd talk to a certified Merc. mechanic for the answer.