1981 Johnson J50BECIC not starting, stalling - suspect carb, please advice

[Carmageddon]

Step #1 would be to take it apart and see if there is something wrong with the diaphragm.---Then look at the various available kits for a match-------Also I can not tell from here if your motor still has the original pump !---Many, many pumps are replaced for no reason at all.----Perhaps desperation or a lack of trouble shooting--I can assure you this would be a simple fix on my work bench !!

I have attached pictures of the pump, can you tell whether it is the original?
It is held by two bolts to the engine block.
How do we look at the various kits, to find a match for this one? I don't see any make or SN on the pump

Oldnbold I do have a fuel sheen in the water!! We just assumed it must be the carb pumping out too much fuel into the ignition chamber!
I didnt know the pump is also connected to the engine in such a way, that the diaphragm is all that keeps the fuel off the engine! Are you saying the pump is covering another opening for the fuel to enter the engine?

 

[racerone]

It is a factory pump !-----Can not tell from the picture if it is the original pump.------Many different years pumps could have been installed.

 

[racerone]

If the diaphragm was rupture fuel would flood into the engine.-----The engine would not run right !----Take it apart and have a look at.it-----Or test it.-----Remove the 2 screws.-----Install 2 nuts and bolts in the pump.-----Operate the manual pump.----Does fuel come out the back of the pump , yes or no ?

 

[Carmageddon]

How do I operate it manually? What would happen to the fuel it pumps in while I would be operating it manually? Will it be flooding in the carburetor, overflowing it?

 

[racerone]

??----The bulb on the hose is a manual fuel pump.----Do you have an owner " how to operate a motor " book.----Any friends / neighbors you can consult.----Sorry.

 

[Carmageddon]

Oh, you mean through the priming bulb, I can activate the pump?
I didn't realize that.

I have no manual at all unfortunately.

I found this one:
https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.ca/ulk/itm/273892135235

The serial number is almost identical except the last C which I read is not significant. Will this be close enough to help me with this engine?

 

[racerone]

No -----when you operate the primer bulb the fuel system will be pressurized.---If the pump diaphragm was ruptured the fuel would pour out of the pulse hole at the back of the pump.-----Understanding how your motor works makes trouble shooting easy.

 

[Carmageddon]

I tested the pump, no leaks (after I sealed the pump with washer and nut like you suggested! Initially was not sure why do that lol...)!

That kinda rules out the pump, right?
Can you at least tell which parts kit is suitable, please?

I assume that leaves us just the carburetor rebuild?

 

[juno pierrat]

try ebay with this search 0438556 - Fuel Pump, prices very widely, just don't order from china, carb rebuild kit is 0396701 - Carburetor Kit with Float

 

[iggyw1]

Carmageddon,

Listen to racerone on pushing the key in while cranjing. Pushing it in 3-10 times does nothing at all. I have the same setup on my 70 H.P. motor. You push the key in, hold it in, and crank the engine to start it. You do this AFTER you lift the "fast idle lever" up. As the motor warms up, you close the "fast idle lever" to the closed position slowly. I do not know why your mechanic would have told you to hold the key on is not necessary when the motor is cold. When it is all warmed up and you shut it off for a little while, only then can you start it without pushing the key in.

There was a guy at the dock just last week that thought that the fast speed lever was the choke. His motor would not start. (the boat was new to him). I told him to hold his key in while cranking the motor, and it started right up for him. Try it.

 

[Carmageddon]

try ebay with this search 0438556 - Fuel Pump, prices very widely, just don't order from china, carb rebuild kit is 0396701 - Carburetor Kit with Float

Thanks! Links are broken, I had to copy text manually and search for "0438556 - Fuel Pump" - found some matches, but they look very slightly different from mine in the picture, including the number in the back of the pump. Where did you get this number?
Is it possible to buy just gaskets and diaphragm for the pump, instead of the whole thing? (although this is already much cheaper than the local dealer quoted)

And what is OMC, btw?

About the carb kit - no exact matches found for OMC0396701... Where did you get the number? in Johnson site, I see 0392061, but I see in ebay items have both numbers mentioned... why? its confusing..

What about that service manual https://rover.ebay.com/rover/0/0/0?m...2F273892135235
It misses the last C in mine (J50BECIC) - is it still a good purchase and would help me?

 

[emoney]

OMC is the parent company to both Evinrude and Johnson...."Outboard Marine Company"

 

[Oldnbold]

Gaskets and the diaphragm are sold as separate parts from the pump.

 

[Oldnbold]

I have attached pictures of the pump, can you tell whether it is the original?
It is held by two bolts to the engine block.
How do we look at the various kits, to find a match for this one? I don't see any make or SN on the pump

Oldnbold I do have a fuel sheen in the water!! We just assumed it must be the carb pumping out too much fuel into the ignition chamber!
I didnt know the pump is also connected to the engine in such a way, that the diaphragm is all that keeps the fuel off the engine! Are you saying the pump is covering another opening for the fuel to enter the engine?

.

Yes the pump is covering another way for the fuel to get into the engine by MiSTAKE ....a hole in the diaphragm. If you were to plug the hole , with your finger, on the side of the cylinder where the fuel pump attaches and spun your engine with the starter you’d feel a suction and a push pulse due to the piston moving past the hole. This same in/out pulsing is what moves the diaphragm to pump fuel. The only other magic the diaphragm has is reed valves making fuel flow 1 way. A hole in the diaphragm would allow uncarburated fuel to enter the cylinder.

 

[Carmageddon]

Ok, I am getting ready to rebuild the carburetor.
I watched this guy's tuning video: https://youtu.be/bsHCMJnRY9A

Do I need this tool? The job becomes more and more expensive!
Is his disassembly and reassembly video correct for mine? He uses locktitte threadlocker afterwards...

 

[Paulywog0667]

I noticed cleaning the jet(s) in carbs (not the pins and seats that come new with kits) resolves single carbs choking themselves out. Probably the bottom carb if two or three. Letting 2 cycle fuel sit will block them.

They're overlooked a lot since they don't come in most rebuild kits.

 

[Carmageddon]

Thanks for the tip, will definitely pay attention to that!
But what about the Carburetor Synchronizer tool he is using? do I need one?
Something like this is cheapest I found:
https://www.amazon.ca/dp/B07Q2M6NPH/...v_ov_lig_dp_it
Or this, cheaper option since the above link does not include tubes:
https://www.amazon.ca/Blesiya-Motor...264023011&s=automotive&sr=1-3#customerReviews

 

[Paulywog0667]

Mine has two carbs. I did a basic 1 1/2 turns on the top and one on the bottom. Increased throttle and kept it smooth with adjustments until back at idle. I melted plug wires on the power head though, but that's 50/50 of thermostat. The fuel pump keeps them full. I might have goofed my linkage and had the lower throttle open with the top at idle too. I had carbon everywhere. I'd probably recommend a carb guage if I knew how to use one, lol.

 

[Carmageddon]

Mine has two carbs. I did a basic 1 1/2 turns on the top and one on the bottom. Increased throttle and kept it smooth with adjustments until back at idle. I melted plug wires on the power head though, but that's 50/50 of thermostat. The fuel pump keeps them full. I might have goofed my linkage and had the lower throttle open with the top at idle too. I had carbon everywhere. I'd probably recommend a carb guage if I knew how to use one, lol.

Thanks! So you saying its not mandatory, I can start the work without waiting for the gauages, but can use them later to fine tune?

1 1/2 turns from full closed, or fully open?
What about a cleaning kit like this: https://www.amazon.ca/gp/product/B07...VNS1HP6X&psc=1
do I need to wait for that before starting? or a simple wire will do for now?
Or something like this: https://www.princessauto.com/en/detail/oxy-acetylene-universal-tip-cleaner/A-p0141002e so I dont have to wait for it..

 

[Paulywog0667]

Last time I cleaned carbs, I soaked them overnight. The next day blasted off the cleaner and made sure spray cleaner passed through. Replaced what came with the kit. If you look at the forum for Johnson. At the top of the page you see the post top secret. One of the links gives a base setting. Which could give a rough idle, but usually at least runs until you're at the linkage with a screw driver. My two carbs start, but it needs to idle higher than I'd like at the settings. It's probably around 1000rpms, but my tach isn't hooked up. Basically if I back out the lower carb ~1/4 turn I get decent smooth idle to play with.