19XX Johnson 3hp 2-Stroke Help

[deputy865]

Sort of inherited this little boat motor, not running of course.

Not sure what year it is, but it's a little Johnson 3hp, Model: JH 19M.

So I first checked the big 3. Air, fuel, spark.

Turned the fuel on, standard. The sticker with starting instructions also says to open the air vent? No idea what or where that is. Proceeded on anyway!

Pulled the plugs, check them for spark. Plugs looked good, spark was nice and bright. Tried to start it, nothin'.

Further investigation. The gas smelled nasty, looked terrible. Drained it, cleaned the tank. Pulled the fuel line and that was full of oil and some sort of solid substance. Pulled the carb, not a drop of gas in it, but it was clean. So, I was thinking I wasn't getting any fuel. Cleaned all the gummed up oil out of the carb. Cleaned the carb, cleaned everything..

Tried to start it today with all new fuel. Still nothing. Fuel was barely dripping out of the petcock (it was cleaned as well) and we couldn't feel any pressure or anything coming from the exhaust.

Suggestions?

How much oil should I be mixing? The sticker said 1/3 pint /gallon. So I did 155~ ml to my 1 gallon of fuel.

Should I feel compression coming out of the exhaust?

Should the fuel be steadily flowing out of the petcock/gas tube?

Shane

 

[nwcove]

Re: 19XX Johnson 3hp 2-Stroke Help

you sure its not a "jw-19"

Johnson Fuel Tank And Motor Cover Parts for 1964 3hp JW-19 Outboard Motor

 

[Daviet]

Re: 19XX Johnson 3hp 2-Stroke Help

Welcome to the forum.
To start with your engine is a 1964.
You have the tank and carb all cleaned out , correct?
#2 is a filter screen inside the fuel tank, it might be plugged with junk if the tank was really bad, pull it and make sure it is clean. The fuel should flow freely from the pedcock when it is open.
On the fuel cap,#3, there is a silver screw. That is the air vent that has to be open.
I would follow the sticker for oil/gas mixture.
Johnson Fuel Tank And Motor Cover Parts for 1964 3hp JH-19 Outboard Motor

 

[jrs_diesel]

Re: 19XX Johnson 3hp 2-Stroke Help

Squirt some 2 stroke gas down the carb throat directly and see if it will fire. If it does fire that means you still have a fuel delivery issue. The "tank vent" is the vent on the gas cap for the tank. It lets air into the tank as fuel is drawn out. Make sure thats open. If your cap does not have a vent you can crack the gas cap loose to let air in. Once you have an air vent, fuel should free flow out from the petcock/hose if it's disconnected. If it does not, you'll need a new petcock. New fuel line won't hurt either.

1 gallon of gas and 1/3 pint of two stroke oil is a 25:1 mix ratio.

You won't feel any substantial amount of air out the exhaust unless it's running with an engine that small.

And JH-19M is a 1964 Johnson 3 HP engine.

 

[deputy865]

Re: 19XX Johnson 3hp 2-Stroke Help

Welcome to the forum.
To start with your engine is a 1964.
You have the tank and carb all cleaned out , correct?
#2 is a filter screen inside the fuel tank, it might be plugged with junk if the tank was really bad, pull it and make sure it is clean. The fuel should flow freely from the pedcock when it is open.
On the fuel cap,#3, there is a silver screw. That is the air vent that has to be open.
I would follow the sticker for oil/gas mixture.
Johnson Fuel Tank And Motor Cover Parts for 1964 3hp JH-19 Outboard Motor

Thanks everyone, you've given me some things to try.

How might I remove and clean that screen? The gas just drips out from the Petcock. I cleaned it out though and any other liquid flows through just fine.

I kind of figured that silver piece on the gas cap was the air vent, we had it open!

I'll try to squirt some gas into the carb and see how that works.

Until now, I have a new problem... Broke the pull cord :/. Is it easy to fix/replace?

 

[Daviet]

Re: 19XX Johnson 3hp 2-Stroke Help

The screen is on the end of the pedcock, it should unscrew out of the bottom of the tank as a single unit.

 

[deputy865]

Re: 19XX Johnson 3hp 2-Stroke Help

The screen is on the end of the pedcock, it should unscrew out of the bottom of the tank as a single unit.

Wondering if I don't have the OEM petcock then.. Because there wasn't screen when we pulled it out and looked at it. Plus we ran liquid through the petcock and it flows just fine and the flow is just fine through the tube. So I'm wondering if there is something in the tank itself stopping the flow?

The flow is literally a drip of gas every... 2-3 seconds.

 

[nwcove]

Re: 19XX Johnson 3hp 2-Stroke Help

there "should" be a larger nut on the bottom of the tank,above the petcock, the screen or scintered metal filter should come out with the nut.

 

[deputy865]

Re: 19XX Johnson 3hp 2-Stroke Help

New we are definitely getting fuel.. Cleaned the tank out... again.. and we're getting a good flow

New problem. Broke the line to the pull start.. replaced it with something strong, but it's a tad thick.. The second problem is that the cord doesn't like to wind back up. I blame the thickness of the cord and the coil might not be that strong anymore?

Any suggestions on some thin, strong line that I can use to pull start this thing?

Getting soooo close!!

 

[nwcove]

Re: 19XX Johnson 3hp 2-Stroke Help

id just use the rope sheave for now, if it doesnt start in 10 pulls it still needs work.

 

[deputy865]

Re: 19XX Johnson 3hp 2-Stroke Help

id just use the rope sheave for now, if it doesnt start in 10 pulls it still needs work.

It's completely shredded. Nothing usable is left of the stock pull cord. Was already old and frail to begin with.

I wish I could get 10 good pulls out of it.. I can only get three or four 3/4 or 1/2 pulls before getting frustrated. Too much time between pulls to waiting for the cord to wind back up.

 

[nwcove]

Re: 19XX Johnson 3hp 2-Stroke Help

remove the rewind starter, there is a rope sheave on the flywheel. all you need is a strong piece of "rope" with a knot in one end, and a makeshift handle on the pulling end . the sheave is on the flywheel for "if and when" the cord or recoil spring breaks on the water, so you can still start the motor. just make sure that no one is standing behind you when you yank the cord.

edit: other than that, your local hardware store will have pre-cut lawn mower cords in the mower/weedwhacker section. ( not as good as oe cord tho)

 

[deputy865]

Re: 19XX Johnson 3hp 2-Stroke Help

Well, we are making due with starting it off of the flywheel.

We are now getting good spark, good new clean fuel and I'm pretty sure we are getting air... but still can't get it to fire. We might get a good chug or two out of it, but nothing that shows life.

Carb is very clean, spark plugs are very clean. Starting to wonder about the A/F mixture screw?

We sprayed fuel down the carb and tried to start it that way without any luck.

Any more suggestions?

 

[nwcove]

Re: 19XX Johnson 3hp 2-Stroke Help

i dont see any mention of compression #'s?

 

[jrs_diesel]

Re: 19XX Johnson 3hp 2-Stroke Help

This is found in the TOP SECRET FILE at the top of the threads list for this forum. Lots of good links in there including carb adjustment.

(Carburetor Adjustments - Two Adjustable N/Vs)
(J. Reeves)

Initial settings are: Bottom high speed = seat gently, then open 1 turn out. Top slow speed = seat gently, then open 1-1/2 turns.

Setting the high and low needle valves properly:

NOTE: For engines that DO NOT have a shift selection, obviously there is no NEUTRAL position. Simply lower the rpms to the lowest setting to obtain the low speed needle va /lve adjustment.

(High Speed) Start engine (it will run pretty rough), shift into forward gear, take up to full throttle. In segments of 1/8 turn, wating for the engine to respond between turns, start turning in the bottom high speed needle valve. You'll reach a point whereas the engine will either start to die out or spit back (sounds like a mild backfire). At that point, back out the needle valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest setting.

(Low Speed) Slow the engine down to where it just stays running. Shift into neutral. Again in segments of 1/8 turns, start to turn the top needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running. Eventually you'll hit the point where the engine wants to die out or it will spit back. Again, at that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

When you have finished the above adjustments, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.

 

[jrs_diesel]

Re: 19XX Johnson 3hp 2-Stroke Help

You'll want to do the high speed needle on a boat. As small as these motors are they will move a lot of water around in a barrel.

I don't know if anyone mentioned it either, but don't forget to check your water pump out before you hit the water. If the impeller has sat for years and/or you don't know when it was last serviced, wouldn't hurt to change it.

 

[Daviet]

Re: 19XX Johnson 3hp 2-Stroke Help

In the past I have removed the prop so I could increase the throttle a little higher if I had a hard time starting one of those engines.
Once I get it running properly, I reinstall the prop and finish setting the low speed needle valve.

 

[deputy865]

Re: 19XX Johnson 3hp 2-Stroke Help

No compression tester to see what the numbers are at...

So basically, I have to get the engine running before messing the A/F screw?

What if I have the A/F screw out right now.. How do I set it so I can at least get it running?

Really at a loss here :/

 

[jrs_diesel]

Re: 19XX Johnson 3hp 2-Stroke Help

You need that mixture screw back in, with it out that will make it full rich on high speed or low speed for whichever one you have pulled out.

The info I posted up above gives a baseline setpoint for both needle valves. And yes, the only way to adjust them is with it running. The baseline setting just gets it in a good position to run in the first palce so you can dial it in.

Make sure you run it in a barrel of water or a bucket or something. You don't want to ruin the water pump impeller which is really easy to do if they are run it dry. You also run the risk of overheating the powerhead as well.

 

[deputy865]

Re: 19XX Johnson 3hp 2-Stroke Help

I've got the screw back in, I'm just not sure where it is supposed to be. Got a decent idea now though.

You're making mention of two of them though? I've only got 1.. I pulled the 1 on the front of the motor.