1965 20' thompson offshore

Suggestions, concerns, and what is the correct power plant for your Thompson.

Moderators: a j r, TDockside, Miles, Moderators

Post Reply
MICHAEL HONERKAMP
Posts: 6
Joined: Mon Oct 23, 2006 7:05 am
Location: CINCINNATI OH

1965 20' thompson offshore

Post by MICHAEL HONERKAMP »

Need suggestions or tips....

I am getting ready to pull the outdrive and engine (120 hp stern drive)
from my boat. I am doing this in order to flip the boat to work on the bottom. Is there anything I should watch out for? I have a manual explaining how to do it but it is not real clear.

any comments appreciated.

Thanks
Mike
Thanks
Mike
a j r
Posts: 661
Joined: Sat Jan 07, 2006 3:09 pm

Post by a j r »

slow and easy. have reliable help handy - folks that can pay attention to your directives.

good luck

andreas
Image
Monhegan
Posts: 8
Joined: Thu Dec 28, 2006 5:05 pm
Location: Maine Mid-Coast

Re: 1965 20' thompson offshore

Post by Monhegan »

MICHAEL HONERKAMP wrote:Need suggestions or tips....

I am getting ready to pull the outdrive and engine (120 hp stern drive)
from my boat. I am doing this in order to flip the boat to work on the bottom. Is there anything I should watch out for? I have a manual explaining how to do it but it is not real clear.

any comments appreciated.

Thanks
Mike

Depends upon drive type. Mercruiser, Volvo, type you will see that remove the retainers, and the hose clamp on the exhaust hose. Then it will pull right off. Old style OMC just pulls off.

I assume you are (have) removed the engine. There is a MAJOR consideration when you reinstall. If it is Mercruiser Volvo type (including LATE model OMC), the outdrive is essentially bolted to the transom, and the engine sits in its mounts on a bed along the keel. The manual will tell you and DO NOT shortcut, you MUST use an alignment tool (a machined shaft) to line up the engine to the outdrive. There is NO WAY to get it accurate without the tool. I don't know where right now, but you should be able to rent the right tool. Ask around your area. (If it is an OLD STYLE OMC, the drive and engine all bolt up as one unit, all mounted to the engine, so alignment is automatic.)

What happens if you don't? There is a rubber filled damper in the coupling between the engine and the outdrive shaft. If there is missalignment more than a couple of thousandths, (whatever the tool allows) this coupling will heat up and the rubber melt out within a few minutes of running.

Working at a parts counter, I once sold three couplings to some gentlemen in an afternoon before they would accept my suggestion that they rent one of the alignment tools were had available for the purpose....... the cost of a single coupling being about ten times our rental fee.

cheers
MICHAEL HONERKAMP
Posts: 6
Joined: Mon Oct 23, 2006 7:05 am
Location: CINCINNATI OH

1965 thompson off shore

Post by MICHAEL HONERKAMP »

thanks for the info on the alignment.... the engine in the boat is a 120 hp
4 cylinder 1965 gmc.... the outdrive is an evinrude... the outdrve
unbolted from the engine & there were 2 pins on the bottom of the outdrive that fitted into slots on the engine frame... is this the model that does not need the aligning tool you mentioned or does it?

thanks
mike
Thanks
Mike
Post Reply