Johnson 30hp help

[chris16371]

I just bought a boat with an unknown year Johnson 30hp. The motor started but ran a bit rough so I cleaned carb (twice) but now I can't get it started again. It will sometimes start up but die immediately. I seated my slow speed adjustment and then backed it out 1.5 turns and the high speed was seated and backed out 3/4. The only way it will fire is choke all the way out and throttle all the way forward. Any help would be appreciated.

Also on the controls there is an idle stop, should that be screwed in or backed out when starting/running? I have it backed out bc I'm assuming you need to tighten it to kill engine but not positive.

 

[james__12345]

On the transom bracket there should be a plate with a model number. That number can be searched to give you a year. If the plate is gone or unreadable the same number should be on a metal plug in the side of the block.
I'm no expert but I would pull the drain plug on the carb bowl and make sure it has fuel and that the float isn't stuck preventing fuel from getting to the carb.

 

[racerone]

sounds like a 1956 model.-----Maroon in colour ??

 

[chris16371]

On the transom bracket there should be a plate with a model number. That number can be searched to give you a year. If the plate is gone or unreadable the same number should be on a metal plug in the side of the block.
I'm no expert but I would pull the drain plug on the carb bowl and make sure it has fuel and that the float isn't stuck preventing fuel from getting to the carb.

Float bowl definitely has fuel in it, I tried starting without the air cover (not sure what exactly it is called) and when I put it back on I had to unscrew the lower adjustment and lots of fuel came out. The viewing glass for the fuel took a bunch of pulls to fill (no primer bulb) but once it was that's when it started to fire with full choke and throttle. I mixed a pint of oil, can of seafoam, and gasoline in a can that holds 6 gallons and disposed of the old gas. I cleaned all jets and passages and blew out with air both times I cleaned carb.

I was hoping to go out on the lake tomorrow but I guess I will be messing around with this.

 

[racerone]

?--------Double hose fuel line ?------------No primer button on the tank ?

 

[chris16371]

?--------Double hose fuel line ?------------No primer button on the tank ?

It's double hose but one says air, no primer button on tank. Could not find the serial number on the transom bracket and nothing on a plug on side of block. I did find some numbers on different pieces under the cover but I'm guessing they are part numbers. I'm about to look them up to make sure.

 

[chris16371]

sounds like a 1956 model.-----Maroon in colour ??

It's black but I think it might of been painted, I see some blue coming through.

 

[oldboat1]

Controls for that motor would be two levers, cable to the throttle on one side of the motor and one to the shift lever on the other side. On the throttle side, there is a plastic adjustment screw under the pan on the side. That's a throttle stop -- no shut off. Choke to stop.

There is a primer pump on the pressure tank in front of the carry handle. It serves the same purpose as a bulb on single line systems (would prime the carb/fill the bowl with that pump). Mix would be 24:1.

Can't tell exactly what you have from your descriptions -- pics could help. If you haven't done so yet, the impeller needs to be replaced if the motor is new to you. (Sounds like you might have the Evinrude version.)

 

[chris16371]

Controls for that motor would be two levers, cable to the throttle on one side of the motor and one to the shift lever on the other side. On the throttle side, there is a plastic adjustment screw under the pan on the side. That's a throttle stop -- no shut off. Choke to stop.

There is a primer pump on the pressure tank in front of the carry handle. It serves the same purpose as a bulb on single line systems (would prime the carb/fill the bowl with that pump). Mix would be 24:1.

Can't tell exactly what you have from your descriptions -- pics could help. If you haven't done so yet, the impeller needs to be replaced if the motor is new to you. (Sounds like you might have the Evinrude version.)

There's 2 adjustments on control, one says idle stop on it and the other says throttle um friction I believe.

I mixed 50:1 bc that's what I'm reading for Johnson 30hp online. So now I need to add more oil? Wish I could find the serial number.

Idk if I'll be able to get any good pics tonight with how dark it is. I'll be up bright and early trying to get it going.

 

[racerone]

56 is the only year for the 30 hp model with the pressure tank.---And yes there should be a primer button on the tank !

 

[chris16371]

56 is the only year for the 30 hp model with the pressure tank.---And yes there should be a primer button on the tank !

I found the primer button lol that would of been helpful before, my arm was getting tired. It doesn't even look like a button, looks like a big flat head screw so that's why I didn't notice it was a button.

 

[lindy46]

24:1 gas/oil mix for that motor. Check compression and spark. Did you install a carb kit while you had the carb apart?

 

[chris16371]

24:1 gas/oil mix for that motor. Check compression and spark. Did you install a carb kit while you had the carb apart?

I added the rest of the oil I needed to. Gaskets are like new and jets and needles are in good shape. First thing I checked was compression and spark which is good, put 2 new plugs in. About had it running but still only with full choke and full throttle, couldn't shut off throttle or choke before it stalled. I contacted my local repair shop, not really something I want to pay for since I have experience with motorcycle carbs but this has me scratching my head.

 

[lindy46]

What were the compression numbers? Should be 110+ and even across both cylinders. Spark should jump a 3/8" gap with an open-air spark tester (not just spark at the plug). Did you remove the welch plug on top of the carb and clean the idle circuit beneath it?