upgrading horse power johnson 150

[tranquility]

I have a 1978 Johnson 150. I have been thinking about trying to increase the performance/ horse power.

If I change the reeds do I need to change the carbs. How involved would this little project be? What all would I need to do to get a substantial increase in power?

 

[Silvertip]

Re: upgrading horse power johnson 150

How thick is your wallet? A new set of reeds, and I will assume you mean Boysen's, will probably give you a little better idle and perhaps a tad on the top end. New carbs aren't needed but rejetting is. But you said you want a "significant increase" in HP so you have two options. One is simple and expensive, the other is not so simple and expensive. Option 1: Buy a bigger engine. Option 2: Find a good two stroke outboard engine builder. Bore the engine, stroke the engine, raise the compression, port and polish, build a custom exhaust tuner, and put in a bigger fuel tank buy a new prop and change the gear set. Buy new carbs and modify the intake. I'm guessing about 4-5K should get you what you want. Did I mention the lack of long term reliability with extensive engine mods?

 

[tranquility]

Re: upgrading horse power johnson 150

That's kinda what I was thinking. But I did enjoy how elequently you stated it.