More power from 6 HP johnson ???

[weekendfisher]

Hey guys,
I was reading about converting the 25hp johnsons to 30's and similar things with the smaller motors.

Can something similar be done on the 6HP, like adding the 9.9 carbs etc or is there nothing that can be done to them to modify the power output.

I have a 6hp Johnson and a 7.5 HP which are just used for auxiliary motors and i have a 9.9 carb from a 98 model sitting around so it triggered my interest.
Thanks

 

[Haffiman]

Re: More power from 6 HP johnson ???

The 7.5 you may forget about, the 6 might depend of year and model.

 

[jbjennings]

Re: More power from 6 HP johnson ???

Not gonna happen with the 6hp.... maybe 9.9 to 15, 20-35hp, but definitely not for the 6.
Sorry,
JBJ

 

[1946Zephyr]

Re: More power from 6 HP johnson ???

Yep, like the above said. The 6hp is a motor of it's own. If you want more power, you just need to buy a bigger motor. The 7.5 and 8 are basically the same and the 9.9 is the same block as the 15.

 

[boobie]

Re: More power from 6 HP johnson ???

Leave a sleeping dog lie. If it runs good, use it as is.

 

[TN-25]

Re: More power from 6 HP johnson ???

A good tune-up & maintenance can go a long way. Also good compression if the rings & walls are worn down. If your 6 isn't performing like a 6, look after the mechanicals & maintenance. Also, too small a motor for the job does not equal better fuel economy, it means the motor works too hard (unless you just troll). It couldn't hurt to make sure the prop is running true to spec. Chewed edges & bent blades rob performance. I don't think there are many props offered for that motor, but it is best to select a prop that lets your motor reach the proper full throttle operating rpm so that it can reach its rated power.

The 6 already was an optimized 5 & 5?. I am assuming you are talking about the 1965 - 1979 6-horse.

 

[Haffiman]

Re: More power from 6 HP johnson ???

from 84 and up, when they had both 6 and 8, they are close to identical, but you need a Dremel to make the 6 an 8, and of course some more parts like carb. Unless you are running on a 8Ft rubber dinghy, you will hardly notice the difference.

 

[raczekp1]

Re: More power from 6 HP johnson ???

yes. 8 hp from 1984 has bigger carb then 6 hp and intake has 3 holes(1leave cover 3 holes) per 1 cylinder,
so look for bigger carb and intake plate
or sell 6 hp and buy 9.9.you will notice bigg differece

 

[weekendfisher]

Re: More power from 6 HP johnson ???

Thanks guys,
The motor runs well and for a 6 it does its job well as a trolling/aux motor but sometimes i get bored and i find it hard to leave things standard lol.
Cheers

 

[Chinewalker]

Re: More power from 6 HP johnson ???

yes. 8 hp from 1984 has bigger carb then 6 hp and intake has 3 holes(1leave cover 3 holes) per 1 cylinder,
so look for bigger carb and intake plate
or sell 6 hp and buy 9.9.you will notice bigg differece

The intake plates will not interchange between the 6 and 8 as the crankcase is also different to accommodate them...