Johnson motor question difficult to start after being turned off for a while

[weekendfisher]

Hi Guys,
I was just after some advice on my johnson 50HP its a 94' model two cylinder twin carb with VRO when i start the motor for the first time like just after dropping it into the water it starts first go never a problem there however if i have been out fishing for a 2-3 hours the restart is a real pain, it takes a fair few attempts to get it started again.
If it has only be sitting for 30-40 mins it starts first turn of the key..
My issue is i cant see why it should be any different from when i first start the boat from cold to after a few hours when it has cooled down.
any tips would be great as i had the same thing happening with my other boat which has a Johnson 55HP which is a 95 model.
Thanks

[FishHunter]

Re: Johnson motor question difficult to start after being turned off for a while

Do you use the choke when you start it out on the water? I only need to choke mine 1st start of the day I also find throttle position plays a big role

1st start off the trailer no throttle at all and choke till she fires which is almost instantly
If restarting almost immediately no throttle and no choke
After a few hours a little throttle and no choke unless its the middle of winter.

If it doesnt start after using choke then full throttle and crank till she clears plugs and fires as they flood very easily.

[weekendfisher]

Re: Johnson motor question difficult to start after being turned off for a while

Thanks fish hunter ,
I usually lift the idle lever to about half way and hit the primer 3 times and turn the key it has never failed me this way so i guess it has become the habit now.
It has the fuel primer system instead of the choke so when i puch the "choke" it injects fuel into the carbs.
I will give it a try the way you have suggested i will leave the idle leaver around half and not prime it see how that goes.
I know the tank and bulb are good as they are fairly new and i can start the motor the next day without having to prime the bulb again.
Can you recommend the best way to avoid flooding the motor as i think this is what is happening.
Cheers

[FishHunter]

Yes, dont use the choke

Sent from my X10i using Tapatalk

[coucho]

Re: Johnson motor question difficult to start after being turned off for a while

hey I had a smiliar problem with my 90 hp johno and for some reason fuel was draining back the fuel line into the tank. If i let my motor sit for any longer than 20 minutes I simply had to re prime the buld and it would start fine but if i didn't reprime it damed if it would start. Next time your out and it has been sitting a while give your bulb a squeeze before you try and start it it should be firm if its not pump it untill it is before you try and start it.

[weekendfisher]

Re: Johnson motor question difficult to start after being turned off for a while

Hey Coucho, the bulb does stay nice and firm it seems to hold the pressure very well as i can leave it for a day then go back and start it up without priming the bulb a day later.
Cheers

[den001]

Re: Johnson motor question difficult to start after being turned off for a while

it is possibly 1 of two thinks,.. these are worst case senarios
bottom crank case seal or you float bowl gaskets...

if the fuel primer is staying hard all day then is is possibly the seal, dont ask what part this plays with hard starting but i had the exact same problem with my evinrude and it fixed the problem...

[gazza2006au]

Re: Johnson motor question difficult to start after being turned off for a while

your either not getting enough fuel or the primer is flooding the engine u say u pump the primer 3 times after the engine has been started for the day with these primers when u go to start the engine for the first time for the day the first 1-2 pumps just bleed the air out of the primer hose the last 3rd pump pumps fuel into the carby's throat when u are actually priming the primer u can feel when its pumping air (moves easier) to when its pumping fuel (moves stiffer) so once your out on the water try pumping the primer only once as all the air would have already been primed out of the hose when u started the engine the first time for the day

[Spaniard_King]

Re: Johnson motor question difficult to start after being turned off for a while

Ar you running champion or NGK spark plugs???

The wrong plugs will give the same symptoms

[den001]

Re: Johnson motor question difficult to start after being turned off for a while

Ar you running champion or NGK spark plugs???

The wrong plugs will give the same symptoms

agreed this is very true, you must run the correct plugs for your specific motor, for some reason it really does make a difference on outboard motors

[captain rednut]

Re: Johnson motor question difficult to start after being turned off for a while

maybe it has a cracked enrichment valve??

[weekendfisher]

Re: Johnson motor question difficult to start after being turned off for a while

Gazza, What i mean by prime is when you push the key in with this motor it injects fuel into the motor to help it start as opposed to choking the motor.
The primer bulb on the fuel line only gets primed up once in the day.

Gary, I have just checked the plugs and they are NGK's the are marked like this
NGK - R BR8HS
10
Are these correct if not what type should be used in this motor ? I would like to change them before friday if they are not the correct ones.
Cheers

[den001]

Re: Johnson motor question difficult to start after being turned off for a while

Gazza, What i mean by prime is when you push the key in with this motor it injects fuel into the motor to help it start as opposed to choking the motor.
The primer bulb on the fuel line only gets primed up once in the day.

Gary, I have just checked the plugs and they are NGK's the are marked like this
NGK - R BR8HS
10
Are these correct if not what type should be used in this motor ? I would like to change them before friday if they are not the correct ones.
Cheers

The choke is the key getting pressed in.

Iboats forum has designated engine threads. You will easily find what plugs it's supposed to run. I had the exact same problem as u. It was the bottom crank case seal.

Has it got the thermostats in?

[Spaniard_King]

Re: Johnson motor question difficult to start after being turned off for a while

You should be runing QL78YC champion plugs these are a projected electrode plug... the ngk br8hs-10 is not a projected electrode plug

[weekendfisher]

Re: Johnson motor question difficult to start after being turned off for a while

Hi Garry,
Thanks for the info i did a little searching last night and found some info on the plugs that recommend the same plug type you have recommended.
Now i just have to try and chase up a set.
Can this model of plug be purchased and any automotive store or will it only be stocked at marine shops ?
Need to try and find a set today so i can get out tomorrow
Thanks for everyones help hopefully this sorts me out.
Cheers