71 Johnson 50 Link and Sync help...

[jbuote]

Hello again!

​So, I have the Johnson 50hp Hydro-Electric. I've rebuilt the carbs and I DID get it to start once. That's the key... Once.
It didn't run long. I shut it down after about 30 seconds. I wanted to check things over again and get my bearings on things since it was a surprise it started..

Anyway,
I followed the procedure from the manual regarding syncing the carbs. The manual says the primary pickup is the "C" location and the note is 4.
Based on that, the time when the throttle SHAFT starts to move is when the cam roller is adjusted such that it is at the center of the marks.
Well, there is only one mark. I've lined it up so when throttle is advanced, the throttle shaft starts moving as roller is at the mark.
Still won't start... It tries!! Coughs, backfires now and then (I may have flooded it too at times...)

Using the start lever, it seems to adjust the timing a LOT and the throttle just a little.. Is that normal??
When in the start position, it doesn't like to crank. Like it's trying to overcome something.
When in the "Run" position, it cranks fine and tries to start. It will "Run" for a second.. Enough to make the starter drop the Bendix so it isn't engaged on the flywheel, but then dies...

Not sure it helps, but I've attached pics of it from today.. An overview, a close-up of the cam/roller, the linkages, and the timer base.
All pics were taken with throttle fully back (Neutral position) and start/run lever in "Run"..
Anything OBVIOUSLY wrong in the pics to you guys with experience??

Thanks!!

 

[F_R]

Don't know, maybe I'm getting old and don't remember, but the short link at the top of the spark advance arm (pic 3) looks funky. Upside down??? At any rate, that shouldn't keep it from starting.

And I don't see anything obviously wrong with the rest of the pictures. I'd say your problem lies entirely elsewhere.

Yes, the lower speeds are controlled mostly by spark advance/retard, with very little carburetor shaft movement until the spark reaches full advance---that's normal.

The safety switch may be keeping it from cranking at full fast idle lever position. Maybe it needs adjustment, or maybe it simply is giving it too much throttle at full lift.

Look for something else wrong. I think you are barking up the wrong tree.

 

[interalian]

Funny, I thought the timing link looked odd as well.

You say when you try and crank at full start advance and it sounds like it's trying to overcome something - could be the battery is weak (or the starter, or a bad connection in the cables or solenoid) and it's fighting the advance. Or you're getting too much advance as F_R says.

On other motors, there's a second notch on the throttle cam just after the sync mark and it's marked START. Maybe put up a picture of the throttle cam when you have the start lever fully up.

 

[jbuote]

Wow!! Good eyes (and memory F_R)...
​I never did anything with that linkage, but sure enough.... Looking at a parts diagram, that link should go from top to bottom on the throttle arm, and into the front of the timer base arm. It is in fact upside down! Dang!! lol....

After I get her consistently running, I'll fix that, but then I'm going to have to re-adjust the timing or will it not change it that much since it's the same piece and length?

I'll take a pic of the start lever in full "Start" position and post that soon..
As for the safety switch, it would cut out power to the solenoid and not even let the engine crank right?
I consistently am able to crank the engine. She cranks at REALLY good speed, so the starter isn't weak or tired as far as I can tell..

Yes interalian,
When in full start advance, it seems like it's trying to fight the advance.. Like it's TOO advanced..
Battery had FULL charge, and is only 3-4 weeks old so I don't think it's a bad battery.
I am going to replace the ignition switch as there is a lot of resistance in it when in the "Run" position. As far as I can tell, that will only affect the choke switch, the shifting solenoids, and the hot horn. Has nothing to do with spark as it's just magneto being grounded in "Off" that shuts it down.. (or prevents it from starting)..
I've wired the shifting to a toggle switch temporarily while I come up with a better solution (original switch casing was cracked and spring sticking out, so the switch is NO good...), so that isn't an issue on the LU...

I traced out each wire and checked continuity, resistance of everything in the wiring harness yesterday.
Aside from the ignition switch in "Run" having high resistance depending on wiggling the key, there is nothing else wrong I can find in the wiring.

Does that help?

Thanks guys!!

 

[jbuote]

No Title

Here's the pics of it in full "Start" position....

 

[F_R]

Just looking at it from a distance, maybe the plastic yoke on the carb throttle rod could stand a turn out.

Timing is controlled by the two screws with rubber bumpers, not the link. Do not mess with the full advance stop without darn good reason (like somebody else has messed with it).

But I still don't think it has anything to do with your hard starting/not running.

It does have a 7/16" spark, right?
It does have great compression, right?
Choke is working properly, right?

 

[jbuote]

Hi F_R..
Maybe turn out the plastic yolk so the cam moves a little further thus opening the throttle a little more at full "Start" position, right?

​Yes, 7/16th Blue "SNAP" spark both Cyl.
Well over 100psi comp, both cyl. NO deviation.. (Was surprising, but checked 3 times...)
Choke isn't working by switch right now, but manual choke is just fine..

 

[jbuote]

Update!

​After making the change F_R suggested, She ran again today!! Seemed more willing... LOL.. Still needs to be tuned properly, so I let it run for a few minutes thinking warming up would help starting the 2nd time.
Nope...

Wouldn't start again..

I took video of the 2nd attempt to start. While watching the video after the fact, I noticed something I'm VERY nervous about. A spark jumping from what looks like the harness to the housing.. I've checked wires and nothing looks bad, scorched or anything...

I'm going to figure out how to post a video and try to post it...

:mad-new:​

 

[F_R]

I tried to look at your video (on your other post). With what you just said here, I'm wondering if the kill wire is arcing out. There are about 300 volts in that wire. I don't know, that seems like a serious arc though. Kill wire is black with yellow stripe.

 

[jbuote]

Again, long overdue.. Adding an end to any open posts I have.. I apologize..

In this case, While I had looked over the wires in the harness, I ended up stripping the harness back a little further and found worn insulation on some wires.. Can't recall which ones now..

Cut, spliced and soldered new connections with shrink and everything, and didn't have an arcing problem since..
Also, it was a flywheel key sheared that was the real problem with not starting every time..

Sorry for the delay in the resolution of this..
She runs like a champ now though..

Thank you all!