1955 Johnson 5.5

[nwcove]

Re: 1955 Johnson 5.5

those screws are NOT meant to be removed for any reason!!!

 

[derrTderr]

Re: 1955 Johnson 5.5

Yeah no kidding. That was a terrible idea.

I got some 4-40 machine screws and was able to get them back in. We'll see how badly I messed that up.

 

[jbjennings]

Re: 1955 Johnson 5.5

As long as the plate is rotating freely, and you have it connected so that there's no chance of a screw coming out (I'd red-locktite the new screw) don't worry about it. If the new screw gets loose you are "screwed" if it gets sucked past the reeds. You're worrying about too many details. If it's got good spark and compression is o.k., the reeds aren'd stuck or blocked open, and the flywheel key is not sheared because you didn't torque it down right it will start and run just from fuel/oil mix being squirted into the carb throat. If good spark, a good flywheel key (correct timing), and decent compression, you should be able to get it to start and run for a few seconds. If you cleaned all the little passages out in side of the carb bowl and elsewhere and got the slow and high speed jets anywhere close to right, it will run if fuel fills the carb bowl. The carb cleaning is not that complicated at all.
To be honest, I never really understood if it ran at all when you squirted fuel into the spark plug holes. Diid it run on it's own for a few seconds or not? If so, see if it will run when spraying some fuel/oil mix into the carb throat. If it does the carb is likely the problem, but if not---your problem lies elsewhere.

 

[Crosbyman]

Re: 1955 Johnson 5.5

something is real screwy if no air suction is felt on his fingers when applied to the face of the carb ??????

we need air-fuel and sparks...

right now we are still missing air...... oxygen being pulled into the carb throath when cranking ????

 

[derrTderr]

Re: 1955 Johnson 5.5

The motor will only turn over about five or six times. It won't run longer than it takes for the starter roper to recoil.

Today I rebuilt the carb, cleaned it with aerosol solvent cleaner and blew out all the passages with compressed air, there are no blockages in the high or low speed needle areas. I'm positive of that now. I rebuilt the carb according to the online procedure and made sure all the mating surfaces were faced and the gaskets lubricated. I tightened everything in a star pattern, didn't overtighten, etc.

I put it all back together and listened carefully as I squeezed the primer bulb. I could see fuel pumping into the filter bowl and I could hear it filling up the carb bowl.

I pulled the starter and no joy. If anything, it feels harder to pull now. When I covered the air intake with my fingers I could feel no noticeable air flow. What would be causing this?

I'm really discouraged today.

 

[nwcove]

Re: 1955 Johnson 5.5

no need to be discouraged! what is your starting procedure when you are putting fuel in the plug holes or directly into the carb? ( no choke...throttle wide open). if you have good spark ( still not confirmed) and half decent compression ( still not 100% confirmed, but more so than spark), the motor should go vroom for a couple of seconds, and make a nice puff of smoke. if not, how exactly does the motor feel when you spin the flywheel by hand with the plugs out? the only resistance you should feel will be the vanes on the water pump rubbing on the housing.....if it feels like more than that....re-read what Chris said about the shock absorber. ( i did notice that in your pic from 09, that one of the green wires from the coil looked like it may be rubbing on the cam?)

 

[HighTrim]

Re: 1955 Johnson 5.5

Now, you do have the right plug wires going to the correct coils right? The Top cylinder goes to the coil directly above the carb, the Bottom cylinder goes to the aft, or rear coil. Swapping these and she will not run. Long shot but something to mention.

If after trying to start, pull the plugs. Are they wet? Do they have fuel on them? Are the plugs themselves actually sparking? Hold them to the block and crank to verify. I have had brand new plugs that were bad.

As Tim stated above, what is your step by step starting procedure?

 

[Crosbyman]

Re: 1955 Johnson 5.5

why not try something new....something ridicoulous since you can't feel the pull of fresh air at the carb face

just take the carb of the motor

... behind it is the intake port to the piston cavities shared by the upper and lower cylinder cavities of the intake manifold ... behind the reed valves.

just work with the one inch round port behind the carb ....the one between the two mounting bolts

have a friend crank the engine crank the engine....

can you feel the vacum pulling (sucking) in the air between your fingers ?? ...you should if you don't the pistons are drawing air from somewhere else. You need to find out where from.

did you remove the power head of the base ( 7 screws to remove, the throttle linkage and fuel hose to the case as in the movie on utube nothing missing/broken underneath ??

http://www.youtube.com/watch?v=SVOedhzPP7M


if it is not sucking air inwards from the carb port it is sucking air from somewhere else. ...work backwards blow air in it from the carb port hole

the air must exit out the respective exhaust ports when the cylinders come down. (remove the exhaust cover to observe/hear)


leave both pistons at half travel with exhaust ports closed. blow air in the carb port ... try to build up some air pressure inside the motor.. look for air leaks

worth a try at this point keep at it... motor must suck air to work

 

[jbjennings]

Re: 1955 Johnson 5.5

The motor will only turn over about five or six times. It won't run longer than it takes for the starter roper to recoil.

Today I rebuilt the carb, cleaned it with aerosol solvent cleaner and blew out all the passages with compressed air, there are no blockages in the high or low speed needle areas. I'm positive of that now. I rebuilt the carb according to the online procedure and made sure all the mating surfaces were faced and the gaskets lubricated. I tightened everything in a star pattern, didn't overtighten, etc.

I put it all back together and listened carefully as I squeezed the primer bulb. I could see fuel pumping into the filter bowl and I could hear it filling up the carb bowl.

I pulled the starter and no joy. If anything, it feels harder to pull now. When I covered the air intake with my fingers I could feel no noticeable air flow. What would be causing this?

I'm really discouraged today.

by
So basically it's not running at all, even with fuel in the spark plug holes. Try turning the flywheel slowly by hand with your finger over one of the spark plug holes. Do you feel suction when the piston goes down? You should feel almost as much suction if you put your hand over the carb throat and make a tight seal with your hand when the piston goes up toward the spark plug. If you're not feeling suction on both sides, your powerhead is making no compression. Since you've verified 60psi, that shouldn't be a problem. I have never used one of those "neon" testers, so all I can visualize is that if any voltage is given, the tester lights up. I think you need to get a $6 adjustable air gap tester from autozone or O'Reilly's and see if the spark will jump a 1/4" gap with a blue spark. If not, that's your problem. Certainly feeling for suction at the intake manifold or carb face would be a wise test. I just can't see how you wouldn't feel suction from the spark plug holes and carb with 60psi of compression unless there's a hole in the crankcase or the reeds were stuck closed.
Wish I lived closer to you----I'd like to see this little devil of a motor in person!

 

[HighTrim]

Re: 1955 Johnson 5.5

I was thinking the same thing, bring her over! lol

Neon testers are good for watching sporadic spark while underway, but no good for determining if the motor will spark while under compression. That is where you need the adjustable tester set to 1/4" for this motor.

 

[HighTrim]

Re: 1955 Johnson 5.5

There was a no start situation like this about a year ago on here. The poster was near me so told him to bring it over. We were on about page 7!

I started it in 1 pull. He had the tiller on STOP. He made me promise not to post any results as he was pretty embarrassed!

 

[derrTderr]

Re: 1955 Johnson 5.5

Yeah I'd love to have a second set of eyes on this thing.

My cold start procedure is:
1. connect fuel line
2. pump primer bulb until firm
3. select neutral
4. set throttle to "start"
5. pull choke full
6. pull starter handle

I will look into getting an adjustable spark tester and the powerhead disassembly tomorrow.

 

[jbjennings]

Re: 1955 Johnson 5.5

Well, something else to check......
WHen you move the throttle, move it all the way to FAST or as far as it will go. WHen you do this, does the armature plate under the flywheel move? How far? I wonder if maybe the throttle gear has jumped some teeth on the tower gear and not giving you enough spark advance for it to fire? Sometimes those throttle gears jump teeth and that boogers everything up. There should be a wide tooth on the gear and a wide slot to accept it. See if they match up. Also, the "start" on that throttle grip doesn't mean much. Put the throttle as much toward fast as you can get it in neutral when trying to start it. There is a throttle stop that will prevent wide open throttle when the shifter is in neutral.
I hope we can figure this thing out!
JBJ

 

[derrTderr]

Re: 1955 Johnson 5.5

The gears mesh nicely on the throttle. I tried starting WOT, still no joy.

Fuel is in the carburetor venturi after starting, in the cylinders and on the spark plugs. I rechecked the gapping on the plugs and it wasn't .030" so I set them. Still no juice.

I checked under the powerhead and discovered the gasket is damaged. Also, the ceramic bushing which rides on top of the spring on the crankshaft had fractured and is in three pieces. May this be the source of my problems?

 

[Crosbyman]

Re: 1955 Johnson 5.5

imho that gasket is there to seal the water jacket flows and exhausts
it should not explain why you cannot get/feel being air sucked into the motor when you crank it up. ( but you do need a new one !!!)

put both pistons half way to close the exhaust ports (remove the side exhaust cover to look sideways and confirm port closures (both )

get some air pressure in the crankshaft cavity (pressurize from the carb inlet hole.. make plate if you have to with smaller hole or nipple to send air to the crankshaft cavity

look/listen for air leaks....remember air will come out your "air" supply nipple behind the carb to the tank ....(normal) so block it off to maintain pressure inside the carkshaft zone ... listen for abnormal air leaks

check top and bottom bearings/seals for hihg air pressure loss ...

those cavities are your motor's lungs ....air can only flow in from the carb face and out the exhaust ports. keeping both closed while you pressurize the motor's lungs ..should tell you if you have inappropriate leaks which would cause the loss of negative pressure (vacum) when your motor tries to suck gas from the carburator during the up strokes.

good luck

 

[derrTderr]

Re: 1955 Johnson 5.5

Ok, here's the skinny.

I removed the exhaust cover and located the cylinder exhaust ports. I turned the flywheel until the pistons were at half mast. I removed the carburetor again and put a vacuum cap on the intake manifold outlet. I took a small flat piece of steel (it was a hardware brace about 3"x1"x1/16") and using the gasket as a template, drilled out three holes; 2 for the mounting bolts and one for the rubber nipple of my air compressor hose.

I bolted my plate to the intake manifold/carburetor mating point and started blowing air into the motor. I could definitely hear leaking and investigated. I could feel air coming from the exhaust ports. I lined up my light and my eyeballs and found that I could see oil flickering on the pistons of both cylinders when I pumped air into the motor.

It would appear that air is leaking around my pistons. What are your thoughts?

 

[nwcove]

Re: 1955 Johnson 5.5

not quite sure of what you were trying to do? ( a backwards leak down test?), but with the rings located midway at the exhaust ports its gunna leak lots of air. i would just go and put a deposit on another compression tester, and confirm it is at what you stated.

 

[HighTrim]

Re: 1955 Johnson 5.5

I think this is getting overthunk

Stick with the basics here. Do you have some pics of the motor, conversion, etc...?

 

[derrTderr]

Re: 1955 Johnson 5.5

I was trying to accomplish what Crosbyman was recommending.

I can take pictures, what specifically should I take them of?

 

[Crosbyman]

Re: 1955 Johnson 5.5

some leakage is expected since the rings would be above the exhaust and intake ports but....no other leaks anywhere is wierd (based on initial symptoms reported and lack of suction in the carb.)

Starting to think this needs fesh eyes myself. any members close to you who could look at it ?