Johnson 15HP cam and cam follower out of wack!! Help

[mltessier]

Just bought my first boat and outboard. Got it home and tried starting it (I know I should of tried before I bought it....). Motor wont start. After some research I found that cam is not connecting with the cam roller. It is far from contacting it in fact. Full throttle and it barely contacts it. It looks to me like the cam is not in the right place? Any help would be appreciated. Motor is a 1984 Johnson 15HP.

 

[jakedaawg]

Has the roller on the cam follower broken? Common for the outer diameter to fall off

 

[jakedaawg]

Maybe make 5 or 6 posts and then try to post up a pic or two

 

[mltessier]

No, the roller is there. It's just to far from the cam. At full throttle it barely reaches the little mark on the cam.

 

[jakedaawg]

Sounds like someone messed with the linkage.

before spending any money...

open air gap spark test with suitable tester set to 7/16"

compression test.

drain lower and have pressure tested. Many shops will pressure test for a reasonable charge if you bring in the lower already drained...

these are to insure you do not throw good money after bad.

 

[mltessier]

Will post pics when I the system will let me. If the linkage as been messed with, is it re-adjustable?

 

[mltessier]

Also, if I Maguyver the the roller with a string and pull on it while pulling the starter, should it start? Or should I not do that?

 

[jakedaawg]

It can be synched but you need to know you are working on a good engine first. Someone messed with it for a reason. No one will waste the time setting it up if you have a bad motor to begin with. Spark check, compression check. Report back.

 

[mltessier]

Will do. I all need now is a compression tester.

 

[heypawpaw]

You say barely reaches little mark wide open. If it is in neutral open throttle as far as you can, at this point cam follower roller should touch at mark on armature plate. This however is not full throttle because if you look on side of engine as shift lever is moved to forward, neutral and reverse, you will see that there is a part (don't know what it's called) that moves in and out only letting armature plate advance to full throttle if in gear.

 

[mltessier]

Yes you are right that was in neutral, my bad. It now moves through correctly when in reverse or forward. What seems to be the problem is that idle control knob on the right side of the engine seems not to work as it should. It seemed to be stuck (could not move it). I ended up freeing it with WD-40, but the little plastic thing is at the end of it'S travel. That in turn moved the cam forward enough for the roller to contact it (I did move it in with the adjusting screw, but it will not move any further). So good news the motor started on the first pull after being in storage for two years. Now it works, but seems to idling rough. Any ideas?

 

[oldboat1]

think you might be confusing the throttle idle stop adjustment (that wheel on the side of the engine), and adjustment for the idle roller -- maybe the carb air mix adjustment as well. The '84 has an idle adjustment needle (carb) -- initial setting is 1 1/2 open from lightly closed. Start and run engine in idle range. After warmed up, slightly close the needle clockwise until the engine coughs ("lean sneeze"), then open about 1/4 turn -- should be close to correct setting. You may find you need to temporarily set it a little richer for cold starting, then return to normal leaner setting.

 

[mltessier]

Sorry I think I'm confusing everybody since I don't know the right words. The throttle idle stop is what was stuck : the plastic thing that moves (goes in and out) when you rotate the idle stop adjustment was fully inside the button. When it was freed, I could move it further out, wich in turn moved the cam forward enough to touch the cam roller/follower. Thanks for the help. I will try adjusting the idle adjustment needle next as per your instruction.

 

[racerone]

Maybe there is a reason that was adjusted like that.-----Do that compression test and post the numbers.

 

[mltessier]

Still looking for a compression tester...