Slow 150 Johnson

[DarrenY]

I have a 1989 Johnson 150 GT and i was wondering what the top speed of these motor is supposed to be i have a 18ft fiberglass bass boat. All i can get out of it is about 43mph. The reson i was wondering was my friend has a 135hp Mercury on the same boat and his does close to 60mph. Is their something that i need to fix?

 

[mikesea]

Re: Slow 150 Johnson

what rpm are you getting and what size prop do you have,props mean alot,also engine hight,dirty or clean bottom,load weight