2004 Johnson 150 upgrade?

[alamosaddles]

Hello. I have a 2004 Johnson 150 on my boat, and I understand that the 2004 150hp and the 175hp utilize the same block, displacement is the same, even the weight of the motors is the same etc. Any gearheads know what the actual difference between both of these motors are, and the approximate cost of upgrading my 150 to the 175 specs?

 

[Chris1956]

Re: 2004 Johnson 150 upgrade?

Normally the difference is port timing, carbs and perhaps exhaust tuning. Do some reasearch on he part numbers of these parts and see.

 

[Dhadley]

Re: 2004 Johnson 150 upgrade?

The blocks have different port timing but they are close. You can use the 175 heads, some 150 models already had them. Even if you went to the trouble to port the block or change it you'd have to have a pretty good hull to take advantages of the small increase in torque.