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

[Carmageddon]

Disaster strikes!
as I was cleaning out the intermediate jet with compressed air after spraying carburetor cleaner, it flew out of my fingers!

It has to he somewhere in the garage, damn it and turns out that the jets are not magnetic! Makes finding it much more difficult...

Hope I find it tomorrow with natural sunlight.

But if I don't? Damn thing doesn't come in a kit.. I now understand those kits are overpriced.. so much for a few tiny parts that cost lol maybe 4 bucks! Meaning they upsell kits at 10 times the cost... Good business.

Any Chinese supplier for the future?

 

[Paulywog0667]

Sometimes part lists have jets listed as orphise plugs. Probably a technical reason, but they're usually not too pricey.

 

[Carmageddon]

Good luck! I found the jet plug, after 24 hours of searching, and ordering a new one (17 bucks CAD..)

Finished cleaning (except the core plugs, opted not to open them for now), reassembled, replaced the NGK plugs with proper Champion plugs capped to 030, reconnected everything - and then:

1. Pumped the pump
2. opened the throttle only to full
3. Turned ignition - it started right away!! revving, I started taking it slowly down, and the engine started choking around 1/3 open (meaning took it down 2/3 of the way), and after a few secs died

Second start attempt at the same throttle position (1/3), started, but then died again after maybe 5 secs or less.

After that got a call from wife as she was sleeping

I guess carburetor needs to be tuned now, right? How? if there are no adjustment screws?
I set the open position of the float to about 38-39mm in both carbs, manual says 28-41mm, float came defaulted to 41mm which is too close to the end of the specified spectrum to my taste...


EDIT: Will make a short video in the morning, to show you what it sounds like when it dies..

 

[racerone]

I would say that you have problems with the motor other than carburetor problems.-----What other trouble shooting have you done.

 

[Carmageddon]

I would say that you have problems with the motor other than carburetor problems.-----What other trouble shooting have you done.

After reassembly,or before?

Before carburetor rebuild, testing fuel pump, testing spark, lots of gas in water when starting unsuccessfully - was gone when vented spark plugs sockets and started without issues, but then not starting again after I shut it down.

At that point,the conclusion seems to have been that the carburetor was flooding the engine with fuel, hence the rebuild effort.

What do you think I should do next?

 

[racerone]

Have to ask,----Do you agree now that there are no mixture adjusting screws on your carburetors.----You have struggled to accept that in my opinion.-----So have you checked the reed valves ?----Checked the flywheel key ?----Does spark jump a gap of 3/8" or better on both leads ?-----Are throttle plates opening at the correct time ?-----Are throttle plates CLOSED when fast idle lever is down with control in neutral ?

 

[Carmageddon]

Have to ask,----Do you agree now that there are no mixture adjusting screws on your carburetors.----You have struggled to accept that in my opinion.-----So have you checked the reed valves ?----Checked the flywheel key ?----Does spark jump a gap of 3/8" or better on both leads ?-----Are throttle plates opening at the correct time ?-----Are throttle plates CLOSED when fast idle lever is down with control in neutral ?

Ok, today in the morning I tried again, this time I did not rush to close the idle throttle, but just to about 1/2 way to let it "warm up" for 40+ seconds, then very, very slowly took it fully down, and it remained running!!

After a few minutes of stable running (btw, NO gas in the water anymore!! so one issue definitely is gone!), I tried to manually push the idle throttle on the carburator link, and it shut down!
Here is video demonstrating this:
https://youtu.be/UW-HLP2K8QM

Same happens when I use two fingers on the upper carb, where I dont have to apply pressure, but can kind of turn it with fingers - it can rev up if I push and hold, but if I do this gentle turn a few times on upper one, it too dies the same way.

What do you think of this? Does it lead to any conclusion perhaps, invalidating some of your questions hopefully?


Your questions above, reformatted:

1. Do you agree now that there are no mixture adjusting screws on your carburetors?
2. So have you checked the reed valves?
3. Checked the flywheel key?
4. Does spark jump a gap of 3/8" or better on both leads?
5. Are throttle plates opening at the correct time?
6. Are throttle plates CLOSED when fast idle lever is down with control in neutral?

Answers:

1. Its just hard to accept, everyone else and where I read says carbs have to have a way to adjust the jets.. I don't understand, how can it be that a carburetor needs no adjustments? because if they can make it so, why others have adjustment screws if its possible to avoid it? Just trying to understand this.
2. Not really, I only inspected top one visually while carburetor was off, and it looks to be sealing it properly. I think in service manual they call this "leaf valve", but I only have partial screenshots of the relevant pages until the manual arrives. How do you suggest I check it? take off carbs again, take off the connector plate to gain better access to the valve? and then what?
3. No, I just looked at videos for lawnmower to understand what is a flywheel key. Where exactly do I find mine? do I need to take flywheel off?
4. I did not test that, only with tester that has light bulb showing rapid blinker, I will get the one that can test using a gap, in open air, I think you suggested in one of the posts? didnt think it important at the time since spark was there.
5. How to check that? what is the correct time for them to open?
6. I think so, I will double check when I get home today...

Thanks again, for the continued help for so many weeks over 5 pages now! I very much appreciate your guidance

 

[racerone]

You need to do proper testing / inspection.-----There are many Johnson outboards that do NOT have mixture adjustment !!----The V-4 model in 1973 did not have them.-----My experience goes way beyond installing new sparkplugs.-----In the last few days I assisted some folks that had paid a shop about $850 CA to get a 1960's 40 HP tuned up.------Without opening my tool box I pointed out a host of deficiencies with the motor.-----Recirc hose off.----safety switch with 2 wires instead of just one.-----A 15 " motor on a 20" transom.----Gear shift did not work--------Electric choke solenoid not hooked up.-ETC, ETC.-----Shop apparently won't help the owner.-----Sad when they charge that much and the owner still has / ends up with a $50 parts motor

 

[Carmageddon]

You need to do proper testing / inspection.-----There are many Johnson outboards that do NOT have mixture adjustment !!----The V-4 model in 1973 did not have them.-----My experience goes way beyond installing new sparkplugs.-----In the last few days I assisted some folks that had paid a shop about $850 CA to get a 1960's 40 HP tuned up.------Without opening my tool box I pointed out a host of deficiencies with the motor.-----Recirc hose off.----safety switch with 2 wires instead of just one.-----A 15 " motor on a 20" transom.----Gear shift did not work--------Electric choke solenoid not hooked up.-ETC, ETC.-----Shop apparently won't help the owner.-----Sad when they charge that much and the owner still has / ends up with a $50 parts motor

I did not mean to cast doubt on what you are saying or your expertise, sorry if that is the impression I gave.

Any thoughts on the information I provided above? especially the video showing how it shuts down when I press on carburetor throttle? or none until I do the checks you asked for?

Can you please answer on how to test points 2 and 5?

 

[racerone]

Opening the throttle without advancing spark is not a meaning full test.----Does spark on your motor jump a gap of 3/8", yes or no ?-----It has been proven on many OMC outboards that carburetors do not need mixture adjustments !!

 

[juno pierrat]

1 yes , some years OMC carbs don't have idle screws, Ive had an 85 and 87 engines, no screw adjustments at all, only sync-n-link, and only 2 jets each, from looking at your year parts breakdown, you have 3 jets ( technically orifice's) , hope you get manual soon
3 you flywheel key is in a key-way at the top of crank shaft , under the flywheel nut. yes flywheel off
5 and 6 are part of sync-n-link
i can kill my motor the same way as in video, nothing learned from that
idling kind of ok , maybe just sync-n-link, and take it to the lake and test run it

 

[Carmageddon]

1 yes , some years OMC carbs don't have idle screws, Ive had an 85 and 87 engines, no screw adjustments at all, only sync-n-link, and only 2 jets each, from looking at your year parts breakdown, you have 3 jets ( technically orifice's) , hope you get manual soon
3 you flywheel key is in a key-way at the top of crank shaft , under the flywheel nut. yes flywheel off
5 and 6 are part of sync-n-link
i can kill my motor the same way as in video, nothing learned from that
idling kind of ok , maybe just sync-n-link, and take it to the lake and test run it

I am not entirely sure about spark a few things:

1. Alligator clips to spark plug, then plugs into cable ( not entirely snapping in, will have to hold manually)? If so, do I need to look at spark only during ignition, or afterwards during regular idle run (assuming it will start)? Is one plug enough, or have to test on both?
2. Schema to flywheel : https://www.crowleymarine.com/johnson-evinrude/parts/43941.cfm?mdl=PQ0VP8 I don't see they key I need to check? Tried clicking on various suspects nothing that looks like a key.
3. How do I test this called sync n link system? Or the throttle timing I was asked to check?

I hoped to do all of that today unfortunately got home late, don't have anyone available to turn on ignition while looking, and service manual hasn't arrived yet..

 

[Carmageddon]

Are throttle plates CLOSED when fast idle lever is down with control in neutral?

I checked this one, attached are 3 pictures:

1. Idle throttle all the way down - closed
2. Idle throttle all the way up - slight opening
3. Idle throttle closed, WOT on the main throttle - it seems to be open more than horizontal position, is that correct?

 

[oldboat1]

throttle positions look correct, offhand. partially open at idle.

BTW:

If your spark tester looks like the one I pictured above (#52?), both plugs need to be removed and set safely aside (sounds strangely like you are trying to wire the plug inline with the tester). Set the gap on the tester -- screws in or out -- fit the tester top in the plug boot like you would a plug, then clamp the alligator clip to a ground (typically, one of the smaller powerhead bolts). Keep the tester itself away from the open plug hole. Crank over the motor and look for spark at the tester contact points.

Don't rev the engine by simply opening up a throttle plate or plates. If you do that without properly rotating the timing plate under the flywheel (i.e., without operating the timing plate in sync with the carburetor), you risk getting a runaway engine (Think two cylinder grenade).

 

[Carmageddon]

throttle positions look correct, offhand. partially open at idle.

BTW:

If your spark tester looks like the one I pictured above (#52?), both plugs need to be removed and set safely aside (sounds strangely like you are trying to wire the plug inline with the tester). Set the gap on the tester -- screws in or out -- fit the tester top in the plug boot like you would a plug, then clamp the alligator clip to a ground (typically, one of the smaller powerhead bolts). Keep the tester itself away from the open plug hole. Crank over the motor and look for spark at the tester contact points.

Don't rev the engine by simply opening up a throttle plate or plates. If you do that without properly rotating the timing plate under the flywheel (i.e., without operating the timing plate in sync with the carburetor), you risk getting a runaway engine (Think two cylinder grenade).

Attached photo of the tool I have.
it only has kV values in jumps of 10, I think 1/8 almost equal to 10kV, right?

I will try tomorrow, Indeed I was thinking of trying it inline -what is a powerhead bolt? There is no cord, I am not sure where to connect it...

About revving- I thought that is how it is revved up, by pushing the throttle, or so it seems this is what I idle throttle handle does?

 

[oldboat1]

If in doubt, can attach a jumper wire to reach a ground on the powerhead -- may need to scrape off some paint for a connection. Point is just to ground the device. The throttle handle will (or should) move the timing plate along with opening the throttle plates in the carbs. You will not be able to advance the throttle in this manner unless the motor is in gear -- fast idle only when in neutral.

 

[Carmageddon]

Is it enough to remove the flywheel locking bolt to tell whether the key is fine, or have to remove the flywheel?
Do I need to torque it to specific number? I don't have the manual yet

Can I ground with the third prong in power outlet instead of a bolt on the engine?

 

[Carmageddon]

I apologize, forgot to attach the picture of tester gap. Attaching now.

I just successfully performed the test as instructed with some bolt that has negative wire connected already!
Video is below spark at the very end of it!
Tested both wires.
https://youtu.be/bJZqdcXqF50

Now I need to find a 1 1/16 socket to open the nut on flywheel and inspect the key...

I don't know how to test timing on throttle though

 

[racerone]

You can not find a sheared key by just removing the nut !----You can not find a sheared key with a timing light.-----The ignition system ( in good condition ) can easily jump the gap at 3/8" or more.---That is the real / proper test !

 

[oldboat1]

Well done! Appears to me to be strong spark, which tells you your ignition system is working properly. If the plugs are in good condition and gapped appropriately, you should have no spark issues. (Timing of the spark can still be an issue if the key is sheared -- flywheel lost its proper position on the crankshaft.)

A couple of points, however: When working with an outboard, you always need a common ground (the powerhead). Also, while you currently have good spark (proper ignition operation), outboard ignition components can sometimes fail or "drop out" when they get hot under operating conditions. That still may mean that spark will be lost on one or both cylinders. I think you can probably find discussions of this by searching on this site for "drop cylinder test".

Good luck to you and happy boating!