Link and sink what the heck is that

jungleplant

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Mar 16, 2006
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i took my 1990 25 hp jonson outboard by the dealers place today and he said that he never seen something so far out of sink , what does link and sink mean <br />and what and how do you do it , mike
 

ob

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Re: Link and sink what the heck is that

It refers to the throttle linkage adjustment with respect to the ignition advance curves.Synching the carburetors allows the flaps to open and close down at equal positions.A necessay critical adjustment for top performance.You'll need an engine specific manual to do the job properly yourself.Once you become familiar with your engines settings ,rechecking the link/synch is a snap.<br /><br />I had cousins that lived in Lodi from the 50's to present Mike.We visited from Tex about once every couple of years.
 

OBJ

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Re: Link and sink what the heck is that

Hi Mike. <br /><br />What it is, is, link and sync. It's adjusting the timing of the engine with the opening of the throttle plate.<br /><br />If you look under the flywheel, you will see a black plastic cam which will contact that little roller connected to the carb throttle plate thru a link. On that cam, there is a little hash mark. When the hash mark is dead center of the roller, the throttle plate should just start to open.<br /><br />If this gets outta wack, along with that long rod going back under the flywheel to the throttle tower, the engine won't run as advertised.
 

OBJ

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Re: Link and sink what the heck is that

Elequently put ob!
 

ob

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Re: Link and sink what the heck is that

I sorta thought yours sounded more technical. :)
 

jungleplant

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Mar 16, 2006
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Re: Link and sink what the heck is that

ok so the butterfly on the carb is closed and the roller lines up between the 2 marks, and the roller starts to move away as soon as i give it throttle, this correct ? thanks guys
 

jungleplant

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Mar 16, 2006
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Re: Link and sink what the heck is that

Originally posted by ob:<br /> It refers to the throttle linkage adjustment with respect to the ignition advance curves.Synching the carburetors allows the flaps to open and close down at equal positions.A necessay critical adjustment for top performance.You'll need an engine specific manual to do the job properly yourself.Once you become familiar with your engines settings ,rechecking the link/synch is a snap.<br /><br />I had cousins that lived in Lodi from the 50's to present Mike.We visited from Tex about once every couple of years.
 

jungleplant

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Mar 16, 2006
Messages
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Re: Link and sink what the heck is that

ya i was moved here in 1960 when i was 6<br />my mom is from texas though , maybe we are related , r u rich. ha ha , thanks for the help
 

ob

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Re: Link and sink what the heck is that

Nope ,I was hoping maybe you were a rich relative. :) My cousins on my moms side of the familys last name was Freeman.They operated a plant nursery and lived on Lodi Ave.<br /><br />Anyway,the two scribe lines on the throttle cam you refer to above are indeed the reference marks for the linkage roller.Since I believe your engine is a single carb ,there is no issue with synchronizing the flap movement between multiple carbs but between the single flap movement and the timer plate position.On your particular engine ,I'm not sure whether the roller should be set between or 'on' one of the lines.Probably between but an engine specific manual could clear that up real fast.Anyhow,the roller is retained by a lock screw that allows for fine positioning of the roller with respect to the scribe line/s on the throttle cam.On my particular engine the roller setting is adjusted so as when the throttle is in the neutral position,the center of the roller should align exactly with the scribe line and 'just touch' the cam slide surface.Mine just has the one line.If you can spin the roller,it's probably too loose and won't allow full opening of carb flap.If the roller touches hard,it's probably too tight and will not allow flap to fully close.Also bare in mind ,depending on use hours,that the i.d. of the roller can become worn and cause looseness.What you're looking to achieve is that the carb flap is 'completely closed at scribe position,and completely hoorizontally open at full throttle position.That's just a general description of the process.Each engine has it's own unique combination of carbs and linkage components so the manual is really a must have.Hope that helped a little.
 
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