78 115HP Johnson - complete novice !

[Vere]

Hi

First time here, but been browsing thousands of posts. Ive been given a Picton 59GT boat (4.8 metre) which has a 78 115hp Johnson motor (Sea Horse V4). Its currently stored out of water and I believe was used last year.

For the life of me I cant find out if its 4 stroke or 2 stroke (don?t currently have access to boat). Also been told that the motor is probably too powerful for the boat, but funds don?t permit changing - any thoughts (other than not putting it at max revs...).

I have it booked in for a service/revision next week, and apart from 4 stroke v 2 stroke, is there anything specific I should ask to have checked out on a motor this old - no service history ?

 

[Chinewalker]

Re: 78 115HP Johnson - complete novice !

Hello Vere,
Your motor is a 2-stroke, 4-cylinder. 4.8m works out to about 15 feet. With, not actually seeing the boat, but running under the assumption that MOST 15-footers would be overpowered with a 115 hp outboard, I would say that assessment is probably correct. Issues with running it overpowered go from your personal safety, to liability in an accident, to loss of insurance cover, to possibility of illegality depending on where you're located.

As for service issues - OMC had some piston problems in the late 1970s with what they called "high ring" pistons. Most of them have been changed out by now, but not necessarily all. They had a tendancy to break easier than the lower ring pistons. Otherwise solid motors and parts availability is still pretty good, at least here in the States...

- Scott