any mods for 175 johnson

[ashelton]

It is a stock 2 stroke v-6 175 horse johnson motor from the mid eighties.
I am looking for some more power and or speed out of it.

It is on my 20 foot exciter and I am running a 21p prop at who knows what RPM.

I plan on adding a jackplate to make up for the fact that my prop is about 7-8 inches below the pad.

Anyone with any luck or unluck with any mods for a 175 johnson let me know... also let me know what prop you had that worked best with it.

Thanks,
Andrew

 

[Costa]

You need to get a tach and see what rpm your turning. Without a tach you wont be able to get much help. We need current rpms vs speed. In my experience with that 21p your probably not turning enough rpm. When I had a 175 w/21p on mine with no jack I had trouble getting above 5400 rpm with my 21p OMC SSTII. You need to get the r's up to the 5800-6000 range. A jackplate will most definately help! With proper setup 6" setback and a hydraulic plate and lwp you should be able to turn a 26p chopper to 5900 with speed around 65-70mph. But this is all just a guess till you get a tach and a speedo.
On mods for that motor there arent really any that wont severly affect its dependability/longevity. The only thing you can do is add a lwp to make sure you have plenty of water flow with a jack.