1999 50 HP Johnson Timing/ Idling issue

[757water]

Hi I am new here but have been reading this forum every since I bought my boat. I have run into a issue that I cannot figure out. When I first bought the boat, I cleaned the carbs and it ran perfect for about 3 years.The model number is J50PSSLM This problem has been getting worse over the last season, with the outboard stalling at idle in or out of gear. The outboard runs great on the top end so initially I suspected the idle circuit was dirty. I have cleaned the carbs multiple times and am pretty confident they are cleaned.

Compression test is 120 psi on both cylinders and the primer system is functioning properly. I conducted a link and sync with the linkages step by step all the measurements are correct and marks are lined up. The motor will not start in this position. However if I advanced the timer base a few degrees it will start and idle out of gear in the water, Once I place it into gear it will die. I have disconnected the spark advance rod from the throttle bodies and if the butterflies are closed if I advance the timing a few more degrees it will idle in gear, timing light shows TDC at 800 RPM which is in specs if I remember right.

I broke a propeller last season, so I thought my flywheel key had sheared off. I pulled the flywheel this weekend and the key and key way was intact. The hub (trigger magnet) and stator magnets are also in place in the flywheel. The trigger magnet notch is lined up with the white mark painted on the flywheel. The timer base looks damaged (rubbing and cracked plastic) but I tested the resistance and everything checks out. I am at my wits end with this motor and would appreciate any input.

 

[TMW123]

2 cylinder, right? Idle timing for that motor is 0-2 ATDC and speed is 775-825.. Idle RPM is adjusted with the IDLE timing screw, which adjusts the timing at idle only. If you cant get the motor to idle correctly between the 0-2 atdc range then check the carb mixture and engine temp.

 

[TMW123]

That RPM and timing measurement is to be taken in the water, unrestrained and in gear btw

 

[jakedaawg]

Check to make sure the two rollers, the timing cam follower roller and the throttle cam pickup roller are intact. The rollers have two layers, a black plastic inner layer and a clear rubber outer layer that tends to flake off. Hard to get a decent idle if the outside layer is gone from the timing roller.

 

[757water]

Thanks for the replies, I have tried to run the engine in the water tied to the dock to get the idle out of gear right. But when I do get it started the spark is advanced out of the marks on the cam, and it barely runs. I have the idle mix screws at 3.5 turns per specs. I actually just replaced the rollers for the throttle cam recently, because as you described it was worn to the bushing. Still having this timing issue, How do I find out if my engine is equipped with quick start?

 

[TMW123]

I dont think it has quick start.. but not 100% on that. Tied to the dock is not good. The manual is very specific about the boat being unrestrained and moving in gear. Don't know if that will make a difference or not.

 

[TMW123]

Also, the marks on the cam where the idle screw is are just a setup reference point. Once idle is adjusted, only the front mark needs to point at the throttle cam. Otherwise, the linkages wouldnt be adjustable but simply set to a fixed length at the factory. someone correct me if im wrong.

 

[TMW123]

And 3.5 turns out on the mix isnt "specs"... its a starting point for adjustment.

 

[757water]

Yes, you are right about the 3.5 turns, I make adjustments to fine tune the idle. My concern is that I have not touched the linkage before, but now I have to in order to make the motor run. My concern having the timing linkage so far out of adjustment, it is like something shifted or isn't firing right.

 

[TMW123]

Why do you think it is out of adjustment? Here, watch this video:

https://www.youtube.com/watch?v=qigy9Ryha2A

Its for an older motor so ignore the linkage lengths but the procedure is similar.

 

[TMW123]

BTW dont touch the WOT timing adjustment.. thats just asking for it.

 

[JerEazy]

If you’re at the 3.5 turns you’re very likely too rich. Do the idle adjustment and it will very likely increase your idle speed. Then you can back off the idle screw and that should bring down your timing reading.

 

[TMW123]

I suspect JerEazy is right, only way to find out is to adjust the carbs, one at a time. turn in 1/8 of a turn at a time with 15 seconds between turn to allow the engine to catch up until engine sputters. Repeat but turn out until sputter.. some where around half way between too lean and too rich will be the correct mixture. Fickle beings, these carbs can be.

Again, manual calls for this adjustment to be done in the water, unrestrained and in gear.

 

[JerEazy]

Again, manual calls for this adjustment to be done in the water, unrestrained and in gear.

Thank you - you’re right in the adjustment procedure - but you can tune the carbs in the driveway or get it close. Then you should just have to adjust the idle speed on the water. I normally set idle speed about 150 rpm over spec on land. Gets it pretty close in the water.

 

[757water]

Ok, I will start from the basics again and report back, I feel that my motor should run without having to mess with the timing linkage. I used to be able to do the 3.5 turns, put it in the water make some adjustments and be fine the rest of the season. Now I get the engine running and it just dies out after idling for a bit in or out of gear.

Thanks I will be gone for a few weeks for work but will definitely update when I get back.

 

[TMW123]

I feel that my motor should run without having to mess with the timing linkage

I want to reiterate that we are talking about the idle adjust screw which sets idle timing only. Please do NOT adjust the actual timing linkage located under the flywheel.

 

[flyingscott]

How did you clean these carbs? Was a link and sync Done? Are you running the VRO yet? Have you tried a different fuel tank? Have you looked for water in your fuel?

 

[MTP67]

I have a 1997 Evinrude 2 cylinder 2 stroke and have been fighting a similar issue. I rebuilt the carbs, synced them, adjusted the air screws (ended up around 2.5 turns out), replaced a bad reed valve, ported the intake while there and replaced the power pack. My timing is set similar to yours. I got all the lines to line up with the rollers. I was able to get the idle adjusted with the linkage adjustment that drives the shaft that opens the butterflies on the linkage that attaches to both carburetors. I had to make sure wide open throttle did not open the butterflies too far so it took some fine tuning to balance everything. The engine runs smooth and top speed went from 28.8 to 30.5 so I feel everything went well on the tuning portion.

I'm having and issue with cold starts and popping back through the carburator/intake. Hot starts are perfect though. Researching.....

 

[757water]

I have only adjusted the idle timing screw so far, the lengths were set to spec, i actually used the youtube video that was posted earlier to do it. Carbs and reeds are good, used torch tip cleaners and a carb dip bucket. VRO was deleted off the motor using a fuel pump now, fuel is good have a water separator with a clear bowl on it. The motor timing seems too retarded to start and run until I advance the timing. The boat runs great on every throttle setting except idle and idle in gear, to start the motor I have to, on most occasions advance the throttle

 

[flyingscott]

Are you using the pump that bolts to the block with 2 ports? Or are you using the 3 port pump and using the pulse line form the VRO.