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1987 Johnson 48 SPL Timing

T

tfish60

Member
Trying to link and sync may 48 SPL. My OMC manual for this engine gives 3 degrees +or- 1 degree, but does not specify if its BTDC or ATDC. Can anyone help?
 
not sure ether, timing light on top cylinder, idle adjustment screw moves idle timing, mines turned in almost all the way, idles all day, not worried about idle timing, just smooth idle, been told not to mess with max advance screw, pre-set at factory
 
scalhoun506 said:
not sure ether, timing light on top cylinder, idle adjustment screw moves idle timing, mines turned in almost all the way, idles all day, not worried about idle timing, just smooth idle, been told not to mess with max advance screw, pre-set at factory
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You have to know your base timing, if it’s wrong there’s no way your advance or wot timing will be correct. Not to mention problems starting, detonation taking place in the cylinder, eventually destroying your power head.
 
Some want to argue on this topic.-----Sorry-----You check maximum timing which is set at the factory for the life of the motor !-------No such thing as base timing on this motor.-----Idle timing is the point where throttle plates open for proper acceleration.------Where the engines idles smoothly the timing does not matter.-----NOTE----This is not the same timing process as you would find on a 283 small block chevy.----Read the manual.----Read it again !
 
my main point is as racerone says "-Where the engines idles smoothly the timing does not matter". but as to your question BTDC or ATDC, don't know
 
racerone said:
Some want to argue on this topic.-----Sorry-----You check maximum timing which is set at the factory for the life of the motor !-------No such thing as base timing on this motor.-----Idle timing is the point where throttle plates open for proper acceleration.------Where the engines idles smoothly the timing does not matter.-----NOTE----This is not the same timing process as you would find on a 283 small block chevy.----Read the manual.----Read it again !
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I see you don’t have a manual or if you do your not able to read. Your about as stupid as a man can get. I QUOTE. 👎
 
tfish60 said:
I see you don’t have a manual or if you do your not able to read. Your about as stupid as a man can get. I QUOTE. 
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You are absolutely wrong. Go ahead and play with your timing and see what happens with your engine. He and others on this site have decades experience and absolutely know what they are talking about.
If this is how you respond to someone taking time out of their day to give you free professional advice I would hope the moderators on the site take notice and ban you from posting.
 
in answer to your question, BTDC and before you ask,because its not labeled either,max is BTDC. i dout that 33 year old motor would even start atTDC
 
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