Johnson 6 hp modifications

[Stoneke]

I posted a thread yesterday re the performance of my 6 hp on my Grumman Sportboat. I received some knowlegeable responses. Short of getting a larger (9.9 hp), are there any modifications possible for this 1974 outboard? Thanks again for your help.

 

[oldcatamount]

Re: Johnson 6 hp modifications

Short of lightening the load in the boat, there isn't much you can do to it.

 

[kbait]

Re: Johnson 6 hp modifications

If you're thinking of getting a 9.9, you may as well get a 15. Same weight. Those sportboats are awesome.. don't see 'em for sale often, and never cheap!

 

[1946Zephyr]

Re: Johnson 6 hp modifications

Yep, the 9.9 and 15's are the same displacement, just different carb set ups. I believe the 9.5's and 9.9's came about, because there are places that have higher licensing requirements for 10hp and bigger. Merc built the 9.8's and the 9.9's too.

So, yes. You may as well get the 15. Your weight will be exactly the same, but you'll have 51% more power.

 

[JB]

Re: Johnson 6 hp modifications

There are plenty of modifications that you could make to your 6, but all are difficult and expensive and make the engine very delicate. The gain in performance on your Grumman would be minimal and not at all worth the trouble.

 

[Tim Frank]

Re: Johnson 6 hp modifications

There are plenty of modifications that you could make to your 6, but all are difficult and expensive and make the engine very delicate. The gain in performance on your Grumman would be minimal and not at all worth the trouble.

....or the cost!...