Whaler Central - Boston Whaler Boat Information and Photos

Posted by docsoma on 07/09/12 - 8:16 AM

I removed ALL the bolts to drop the lower unit of my 2-stroke 40hp Yamaha (1991 40ELRP). Yes, I removed the trim tab and the bolt hidden there ( actually the head of this bolt snapped off.....separate problem).

I am unable to free the lower unit. Scared to bang around with a mallet....seen many posts on broken cavitation plates. I am just able to insert a exacto plate about 75% of the way around. Tried dental floss....no good.

Any tips?

Posted by Phil T on 07/09/12 - 11:59 AM

Doc-

Give it a bear hug and shake fore and aft and sideways. There are pins that can get a bit frozen.

When was the last time it was dropped?

Posted by docsoma on 07/09/12 - 12:07 PM

Phil, (Doctor Phil?!!),

The history of my boat has been mentioned in my previous threads. Since I boat the boat in 1993 (probably with less than 20 hours on the motor) the Lower Unit has never been opened.

Would you suggest a mallet treatment in addition to the bear hug?

Posted by CES on 07/09/12 - 8:40 PM

Kindervb wrote:
What about the shift linkage?

Nailed it.

Aside from the bolt thats hidden under the trim tab, and the four that are visibly seen....the shift linkage is the only other thing that could possibly hold it on is the shift linkage.....be careful un doing the linkage because when you go to re install the lower unit, you could mess up the shifting into forward and reverse and will have to re adjust to get it shifting properly again.

Do not us a hammer.....metal of rubber, on your cavitation plates.....don't ask me how I know. lol

Posted by docsoma on 07/09/12 - 9:01 PM

Thanks to all for your generous advice.

I think the culprit is the bolt hidden by the trim tab whose head I managed to snap off. I think there is just enough of the bolt that is stubbornly holding on to the lower unit. My guess is that the bolt (Yamaha part Number 97395-08085-00 BOLT) is not threaded along its full length...so a little persistence will let it free up the Lower Unit.

In any case I now have the additional adventure of using an Easy Out to get the remaining bolt out which in turn means having to remove the propeller.

Posted by Geo on 07/10/12 - 4:01 AM

You might be amused to learn that after 26 years, my 1986 Yamaha 50 hp 2-stroke finally had to have its water pump / impeller replaced for the first time this summer. And that motor is used in salt water. However, I do flush the system out with fresh water on a fairly regular basis. The bolts holding the lower unit on were frozen and had to be ground off in order to remove the unit.