Wont get on plane

im new to this site but it seems from what i read everyone here knows what is going on. my problwm is that i have a 17' flare with a 1974 70 hp johnson. sounds and runs great out the water but in the water the enginge wont rev up all the way or get on plane. just put a new linkage rod in for the timing advance and it helped but didnt solve the problem. any ideas?

 

Get thee to a propellor shop and have them take some pitch out of the prop! That's a quick solution to what could turn out to be a complicated problem. I mean it's possible that your boat has gotten too heavy. Did you add a whole bunch of stuff to it? Is there a bunch of water in your boat? Is your motor just to tired to put out the horsepower it used to in 1974? Eeeehhhh....re-pitch the prop...

 

70 Johnson

Just a guess- but before you spend big bucks on anything, check your carbs. The jets in the older model Johnson and Evinrude motors are in the bottom of the float bowl- if there is any junk (like melted old gaskets from too much carb cleaner or years of service) floating around in there, it will run 'OK' when you start it in the yard but be starved for fuel when asking for real power in the water. Check all lines and filters too.

Gaskets- $10
Satisfied feeling it was something really basic- priceless.

I have a 70's vintage Johnson 115 too, bought it for a great deal because the previous owner had a similar problem and thought it was about to start costing $$- all I did was the above and it has been running great now for over 5 years.

 

great good answer rick a few ppl said the said something about the same thing. thanks for your help to thunder but general propeller already did there math to figure out the prop for it. imma ru nthe carbs down to the mechanic today
you guys are great and hopefully it fixes the problem
Mikee