Mercruiser 120HP in 1978 Glastron SSV-172 engine problems

[Ruudsch]

A couple of years ago I bought a 1978 Glastron SSV-172 with an inboard Mercruiser 120hp enige and a pre-alpha tail.
When I bought the boat it was badly maintained, so i knew it needed some work.
In the last years we fixed:

- Refurbished carburrator
- New dynamo
- Refurbished tail (pre-alpha)
- Transom and Gimbal checked

So now the engine run stationary without any problems. In the beginning the enige runs without any problems.
The problem is: When the enige gets hotter I experience a loss of power. When we tune the enige when it's hot, it runs good again. When cold again, the engine runs dramatically bad.

Does someone have experience with these kind of old engines? And can you point me in the right direction?
There is no problem with the fuel delivery to the engine.

Thanks in advance!

 

[Bondo]

Ayuh,..... Welcome Aboard,...... Have the points, 'n condenser been changed lately,..??

 

[Ruudsch]

Thanks for your reply.
There are no condeser changes for what I know.

 

[thumpar]

It has points and condenser unless someone put in an electronic conversion. They are in the distributor. Make sure the timing is set and you are getting advance also.