85 HP Johnson wont start back up without starting fluid

Tmacular

Petty Officer 1st Class
Joined
Jul 4, 2007
Messages
200
73 Johnson 85hp. New motor to me and I took it out first time today. For some reason its not restarting after sitting a bit without a shot of starting fluid. Afterwards starts up fine and runs great all day. During the failed attempts to start, it will occasionally start and stall out when trying to put in gear.

However like I said, it runs fine all day long after its started and warmed up as long as I dont shut it down. Otherwise repeat above.

I was going to clean the carbs but I feel its a waste given that it idles good and runs good. So question is whats next best option.

Idle adjustment/fuel filter is something I am planning on doing, any other possibilities to look for? If those don't solve issue I will move to carb cleaning etc.

Thanks
 

Bosunsmate

Admiral
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Apr 7, 2012
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6,129
Re: 85 HP Johnson wont start back up without starting fluid

Is the choke working ok?
 

rrw

Petty Officer 2nd Class
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Oct 9, 2011
Messages
104
Re: 85 HP Johnson wont start back up without starting fluid

Hi, Did you try squeezing the fuel primer bulb when trying to restart it? Fuel pump may be weak, or losing prime. If that's not it, may have a weak spark issue. Also I wouldn't spray starting fluid into a 2 stroke, it doesn't contain any oil and actually washes out the oil that is there. I use a spray bottle with mixed gas. Hope this helps, if not I'm sure someone will point you in the right direction.
 

Tmacular

Petty Officer 1st Class
Joined
Jul 4, 2007
Messages
200
Re: 85 HP Johnson wont start back up without starting fluid

I did check spark and everything was looking good. Choke is also working fine. I did suspect possible fuel pump but also put aside because it runs so smooth.

Today after it did it, I ran it without shutting it off for over an hour and half and it never stalled or sputtered or kicked or anything. I actually switched to squirting some fuel line gas into it that was mixed. I just dont want to spend more money then necessary to chase down the problem , just hoping to start with most relevant and move down.

Thanks again
 

rrw

Petty Officer 2nd Class
Joined
Oct 9, 2011
Messages
104
Re: 85 HP Johnson wont start back up without starting fluid

Hi, The pump may work while running because there is a lot more vacuum at 700-5000rpm then at 300 when its cranking, not to say for sure but that's where I would be looking.
 

pn

Petty Officer 1st Class
Joined
Apr 20, 2013
Messages
374
Re: 85 HP Johnson wont start back up without starting fluid

Listed in monetary order:

Basically fuel is not getting to your float bowl, or not staying there-leaking out.
Make sure there's no leaks in fuel line, tighten as necessary. cheap fix free, tighten any loose screws on carb, carb to manifold, blow out all lines for unobstructed flow, including gas vent
Does primer Bulb holds pressure, firm before startup and doesn't loose pressure.
Primer bulb a little more expensive maybe 6 bucks off ebay

Is there a drain on your carb, possibly check when your having problems on the water, no fuel equal no start

Fuel pump kit due to weak or failing, 10 or 15

Carb Float sticky, carb kit 25.

hopefully your (check wires) starter motor spins fast enough to start as well, possibly lube up that bendix gear.

good luck
 

Solittle

Fleet Admiral
Joined
Apr 28, 2002
Messages
7,518
Re: 85 HP Johnson wont start back up without starting fluid

I'm bettin on the choke. It may be working fine but you need to use it when starting. Describe what you are doing to start now in detail. Some engines need 5-10 seconds of choke plus the primer throttle to get going. Quite normal when you figure out it's personality.
 

Prestone12

Recruit
Joined
Apr 29, 2013
Messages
2
Re: 85 HP Johnson wont start back up without starting fluid

I have a 71' 50 HP Johnson and I have to pump primer bulb and choke it every restart everything is brand new and rebuilt. So I guess its just a learning game.
 

Tmacular

Petty Officer 1st Class
Joined
Jul 4, 2007
Messages
200
Re: 85 HP Johnson wont start back up without starting fluid

PN- Thanks you will look into in that order.

Solittle and Prestone - I was told from a friend who had same motor about priming the bulb before every restart so with that in mind my attempt to start is as followed. Pump primer bulb hard, hold choke and turn over, it took multiple tries of choking with no start. I have also attempted choking it and lifting on the neutral rev for warm up and nothing either.

You could be right in the fact its a learning game for me. New motor and it might have some tricks to it :). I am a previous Chrysler owner so these are very unfamiliar.

I ordered a fuel pump from my local marina, checked fuel lines and no leaks anywhere, and I did not see any gas leaking from carb either. Also ordered filter. Will see if that changes details and report back. Also doing a compression test to check, what is a good compression for these motors?

Thanks again ,

Tmac
 

EvstaG

Seaman Apprentice
Joined
Sep 17, 2012
Messages
32
Re: 85 HP Johnson wont start back up without starting fluid

I believe these motors were shipped with 125 psi on each cylinder from the factory. For an engine of that age, I would consider anything above 100 psi would be "good" , however the more important figure is ensuring that they are all within 10% of each other. Perhaps someone with more experience can either confirm or correct this thought. I have also heard of people having great-running engines with compression in the 90 psi range for years; all of these motors had each cylinder within tolerable levels of each other.
 

Prestone12

Recruit
Joined
Apr 29, 2013
Messages
2
Re: 85 HP Johnson wont start back up without starting fluid

Well thanks for the input. I have been working on the boat non stop this week. Opening weekend fishing this weekend. Today for some reason pumped the primer one time to hard turned the key and she fried up with no starting fluid or choke. Started up everytime even at an idle. I think its because I finally got my mixture right and timing on..
 
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