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1985 70HP - J70TLC0S ignition specs

L

Londonlad

New member
Hi.

I have searched, but can not find any specs regarding ignition timing. My engine is a J70TLC0S. Any help would be appreciated.

Cheers
 
Timing on these motors is set at the factory for the life of the motor !-----What is your motor doing / not doing ?
 
racerone said:
Timing on these motors is set at the factory for the life of the motor !-----What is your motor doing / not doing ?
Click to expand...

Hi.

The original engine crankshaft was damaged by the splined shaft of the Jet outboard, so I got a short block and swapped everythink over to the new block and rebuilt the Jet outboard.

Every thing had to be reset up.


I copied the settings as best I could for the advance stop, but will not know if it is correct until I get her out on the water and check the WOT advance, thats why I wanted to know what the 2 timing settings were supposed to be.

I have an OMC workshop manual but it is from an 1982 model, so I just wanted to be sure of the settings. I have not been able to find an 1985 copy of the OMC manual.

The 1982 manual says 19 deg +- 1 deg.

At the moment when warmed up it is showing TDC when I have a strobe attached to #1 spark plug at idle, running with a flush on the jet.

Not sure what the timing should be at idle. I do have another manual which covers this engine and If I read it correctly it should be 3-5 ATDC, so not sure what it should be at idle.

I am new to outboards so any help is appreciated.

Cheers

Ian
 
Max advance is 19 deg for.that motor. Use the joe reeves method of timing much safer and easier. You do not care about idle timing that takes care of itself.
 
Hi.

Found the method. so basically it is

Remove spark plugs, and move other leads out of the way.

Insert spark plug tester in #1 lead and ground the clip.

Place timing light on #1 lead.
On my boat I had to use tying wire to hold the carbs open at full throttle position after disconnecting the throttle cable linkage. I could not crank the engine with the controller at full throttle.

Use tying wire to hold advance plate up against the stop.

Crank the motor to observe the timing advance.

Mine showed 18 degs.

I retarded it back by 4 turns to 15 degs when tested again. So when running at full throttle in the river I should be at 19 degs (15 + 4 from CDI)

Did I do this procedure correctly?

Cheers

Ian
 
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