1972 Johnson 85 hp link and sync or timing first?

[jquinn13]

I have a 85esl72r Johnson outboard. Should I "link and Sync" first or time the engine first. When I accelerate is cuts out. Carburetor kits come next weekend, ( Had them rebuilt last year). The kill switch I just moved it to allow the motor to turn over in neutral. I think that is beginning of linkage not being set right. Yes shift works in forward and reverse. What is the correct timing procedure and proper adjusting of carburetor linkage? Yes I have a shop manual. No there is no mechanic in my area literally. Help with correct linkage pics and timing instructions and experience help ( beginner mistakes to avoid) would be appreciated. JQ

 

[jayyyy]

Re: 1972 Johnson 85 hp link and sync or timing first?

The total timing advance should be around 26-28 degrees. unless someone adjusted the stop screw it should be fine. There are ways to check total timing advance without a dyno, I think the procedure is in these boards. You really need an OMC service manual to do a link n' sync but basically with the throttle in neutral the carbs should be all the way closed (butter flys shut). With engine running and the warm up lever in up position the initial timing should be 4-6 degrees. As throttles advance timing also does, timing slightly ahead of throttle. This procedure is very basic and generic but should help with the big picture.

 

[jquinn13]

Re: 1972 Johnson 85 hp link and sync or timing first?

Thank you JAYYY, Yes I have a Timing light. And a manual. According to you, Basically start with butterflys shut, then tighten linkage, then turn on engine and Do I use the "Idle adjustment screw" or the "full throttle adjustment screw" to advance timing? I think manual says to use Idle adjustment screw when turn on motor in idle [5 degrees but you say 4 degrees] then the full throttle adjustment in WOT [you say 26-28 degrees, manual says 28 degrees]. As I write this it seems obvious. Top secret files says to use 4 percent less than manual. (28 times .96= 26.88) (5 times .96= 4.8) Let me know. You are giving me confidence. JQ

 

[jquinn13]

Re: 1972 Johnson 85 hp link and sync or timing first?

What is relationship between the "Spark adjustment crew" [under flywheel], the " Idle adjustment screw" and the "Full throttle adjustment screw"? Do I adjust one first, then the others? Or do they have to be "adjusted" together at same time? I'm going to count the threads on each adjustment screw shown in the Johnson Manual for starting positions on all three. I'll connect timing light to spark plug one to check timing. Which adjustment first? in there a specific order? Is it combination of engine sound with timing readings? Am I over thinking this too much? JQ

 

[jbjennings]

Re: 1972 Johnson 85 hp link and sync or timing first?

A couple of questions: How long have you owned this motor? Has it ever run like it should?

If the motor has run like it is supposed to since you owned it, leave the darn timing stop screws for idle and wide open throttle alone. They have lock nuts and practically never get off.
You have a '72 model. I believe you have a battery CD ignition system with a timer base under the flywheel. My suspicion is that you are getting bad or intermittent spark due to a bad CD ignition box (availble from CDI -an aftermarket parts company), bad spark plug wires, or possibly a weak stator.
Have you checked spark with an actual spark tester to see if it will jump a 1/4" or 3/8" air gap with a hot blue spark on every cylinder? If not, you should.
If your throttle plates in the back of the carb are all fully open when you have the throttle all the way forward, and the throttle plates are fully closed in neutral, then they are likely synchronized as well.
Just my opinion,
JBJ

 

[Cjchev12]

What are the spec on timing on the 1973 Johnson 85hp. I have replaced every thing fuel and spark but still have a miss fire and only get half throttle and shakes real bad

 

[GA_Boater]

What are the spec on timing on the 1973 Johnson 85hp. I have replaced every thing fuel and spark but still have a miss fire and only get half throttle and shakes real bad

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