Re: 77 Johnson 85hp turns over but wont start?
These motors get "cold" and will not start without complete choke. Does your electric choke work? Mine is broken so I have to pull the cover and manually close the choke. Then if the motor is cold (can happen in as little as 20-30mins) I have to physically hold the choke valve shut because the choke is not adjusted to close 100% tight. I pulled off the air intake cover to do this, doesn't matter it's just there to reduce noise as far as I can tell, and the noise diff is not huge. I use the handle of my paddle or fishnet as they're long enough to reach the choke valves while turning the ignition key.
Make sure your fuel bulb is totally hard for starting. If it doesn't get hard then you need a new bulb.
Finally your battery has to be totally charged up. Even if it turns the motor, that can be insufficient. It has to turn the motor fast at a normal speed as when fully charged. I think most owners on here have pretty big batteries too, with a lot of cranking amps. Mine says 750 "marine cranking amps" at 32 degrees F, and 600 cold cranking amps at 0 degrees F.
Changing the plugs can't hurt. Your gap is probably .030, most of these motors are.
The experts here are going to recommend you buy a spark tester (NAPA auto parts has them) and make sure you have at least 7/16" spark on all cylinders.
But my money is on the fuel/air/choke issue. Try manually closing the choke all the way tight & see what happens.
Also you can try spraying fuel/oil mix directly into the carbs to give it a start, but don't use Ether-Based "starting fluid". Most here will say that using premixed fuel in a spray bottle is the best way to go. Many say that for diagnostic purposes it's OK to use a can of something non-ether-based that you buy over the counter. Even Seafoam "Deep Creep" is supposed to work as a starting fluid (per the can). I use a 3-in-1 product that has lubrication and is non ether based. The problem with ether (per what I have read here) is that it has no lubrication and can quickly burn a hole in your pistons.
But for longer term, you'll need to fix the fuel / air or spark issue that is causing the hard starting condition in the first place. Don't rely on sprays and McGyver solutions for the long term.
