1968 Evinrude 9.5 trouble

[Bobby D]

Purchased a used motor - got it running after replacing needle and seat, fuel line to carb which was leaning on spark plug and had a hole burnt in it. Replaced thermosat and checked lower unit. The problem is one that seems to come and go. When I run the motor with the cover off it runs great. when I put the cover on ( after leaning out the low idle) it runs ok for a short time than quits...it is difficult to get started after this happens and will only run with no throttle...if you give it gas it dies??? help anyone

 

[F_R]

Re: 1968 Evinrude 9.5 trouble

Are you running it in a barrel? They won't run in a barrel with the hood on.

Or are you running it on a boat? Two notorious causes:

The seal on top of the water pump housing. If somebody left it out when changing pumps, it will leak smoke under the hood and it won't run with the hood on.

The seal around the shift rod. It is a bellows boot type thing that you can't even see. But they are very bad about splitting. When they do, it is the same result as the water pump seal

Both the pump seal and the shift rod boot are obsolete. I have a cure for the shift rod boot, but my lawyer says I can't sell it. Liability thing, you know.

 

[reload]

Re: 1968 Evinrude 9.5 trouble

I once experienced a situation where the motor ran hot with cover on and cooled just enough with the cover off. When examined the pump was questionable and the t-stat was half plugged.