I have a good 1981 25hp Johnson and a dead powerhead on a 1981 35hp Johnson. Both engines are the same displacement, what do I need to make the 25 into a 35?
Re: whats the difference in 1981 Johnson 25hp and 35hp
The core powerheads are pretty much the same. If you take the intake manifold & carb off your dead 35 and install it on the 25, then put the 25 powerhead on your 35 chassis, you should be good to go. The '81 25hp lower unit's exhaust system will restrict the 35hp powerhead, so it is best to use the 35hp lower end...