Johnson 50 carb air screw setting

[JerEazy]

J50PLSSM

Rebuilt the carbs but didn’t count the turns removing the air screw on the starboard side of the carb (spring loaded screws)

I read 3.5 turns out to start but nada. Can’t get her to start without throttle and no dice on idle.

any guidelines or tips for setting?

thanks!

 

[lindy46]

I find mine idles best at 2.25 turns out. Same motor.

 

[JerEazy]

Ok - I’ve got another issue at play then.

on a whim I checked timing while wife turned the key trying to start and I’m more than 4 deg ATDC on timing.

 

[jimmbo]

Did you mess with or adjust any part of the linkage?

 

[JerEazy]

When I put the carbs back on I made sure they were opening and closing fully. Lines up the pickup and made sure WOT was turning the plates horizontal.

based on just those adjustments I’m sure the rest is off and needs a full link and sync.

not overly familiar with this linkage style - any advice or walk through would be appreciated.

New motor to me.

 

[boobie]

You've got something else wrong, not just an air screw adjustment.

 

[JerEazy]

You've got something else wrong, not just an air screw adjustment.

Yeah - I’m going to J Reeves the WOT timing and then check the idle after that. Timing is off for sure.

 

[jimmbo]

Do you have a Service Manual, hopefully one by OMC?

 

[JerEazy]

Do you have a Service Manual, hopefully one by OMC?

No sir - just acquired the boat/motor and going through “the basics”. Previously owned a 50hp and some other OMC power.

boat.nfo is a seloc manual it’s seems. Factory manual is on the order list. But this video helped.
https://youtu.be/qigy9Ryha2A

 

[lindy46]

The link and synch procedure on this motor is very specific. It must be done in a certain sequence. A service manual is a must have item.

 

[JerEazy]

totally agree. it's on order

But i believe the sequence is:

carb sync (ensure fully closed and ensure open at the same time)
line up pick-up cam roller for carb linkage
WOT spark timing
Idle speed
WOT throttle stop

if you have some pictures of those manual pages you could send my way so i don't have to wait on the USPS during the holiday season, i would be grateful.

 

[lindy46]

No sir - just acquired the boat/motor and going through “the basics”. Previously owned a 50hp and some other OMC power.

boat.nfo is a seloc manual it’s seems. Factory manual is on the order list. But this video helped.
https://youtu.be/qigy9Ryha2A

This video is helpful, but some of the settings are NOT CORRECT for a 2000 50hp. motor. For example, you don't adjust the idle stop screw so that the cam riding in the slot aligns with the pointers. The timer base rod is adjusted to 2.5 inches, NOT 2-1/16 inches. That's why a manual is a must.

 

[lindy46]

Send me a PM with your e-mail address and I'll send you a file.

 

[JerEazy]

Sent

 

[JerEazy]

Going to start new thread with correct topic