20r70e 1970 johnson more power

[noobis]

hi everyone bought a 20r70e 1970 johnson 20hp outboard on a 12 foot plywood boat. engine seems to be running nicely and has recently had a bit of an overhaul however just does not have the power I would expect from a 20hp engine.

I have adjusted the throttle since last trip out as i was not quite getting full throttle how it was previously adjusted, so that may make it a bit better.

the propellor is not in too good shape, is rather blunt with a few chips in it that could not really be sharpened out. I was wondering how much the state of the propellor affects the output. What affect does putting different sized props on an engine have?

also does adjusting the tilt of the engine help the boat plane better on the water?

if you have any other suggestions that would be much appreciated.

thanks very much for reading!

 

[tashasdaddy]

Re: 20r70e 1970 johnson more power

proper set up is critical. the AV plate ( light green) needs to be even with the bottom of the boat. tilt pin adjustment, closer to the transom, pushes bow down, further away pushes bow up. red is water pickup, yellow exhaust, bright green is the exhaust relief ports and at idle should get mist or drops of water out of it.

also proper carb setting, and link n sinc.

read this http://forums.iboats.com/showthread.php?t=299680

 

[noobis]

Re: 20r70e 1970 johnson more power

Ok after making all the changes you suggested there is no real difference. Does inproper carb setting make a big difference to the performance. As the carb could well not be set right. I have seen instructions on how to set the carb on other posts about this same engine so I could try those if you think it will make a difference.

Thanks

 

[tashasdaddy]

Re: 20r70e 1970 johnson more power

carb and prop definately effects performance. http://forums.iboats.com/showthread.php?t=299680

 

[noobis]

Re: 20r70e 1970 johnson more power

Ok thanks. Your a legend