Syncronizing Butterfly Valves in 70 Johnson

[17isme]

How do I syncronize my valves in my engine? I am not turning the right RPM's that i am supposed to be turning. Any information will be appriciated!<br /><br />J.A.Z.Z.

 

[Hooty]

Re: Syncronizing Butterfly Valves in 70 Johnson

Adjust the linkage between the two so that both butterflies are full open together.<br /><br />c/6<br /><br />Hooty

 

[JB]

Re: Syncronizing Butterfly Valves in 70 Johnson

Hi, JAZZ.<br /><br />The procedure for synchronizing your carbs is 5 pages and 8 pictures in the Clymer Manual. It also includes setting the carb/ignition timing.<br /><br />Unless you are an experienced wrench, you can't do it without a manual. The factory manual is much easier to use, but you still have to recognise parts by their technical names or by pictures.<br /><br />Here is a simplified procedure:<br />1. Retard the throttle until the throttle cam roller does not touch the cam. Advance the throttle until the throttle cam roller touches the throttle cam. If all three throttle valves begin to move at the same time, skip the rest of the procedure. If not, retard the throttle again and go to step 2.<br /><br />2. Loosen the top and bottom throttle lever adjustment screws. The return springs should close each throttle valve. Open each slightly and allow the spring to snap them closed.<br /><br />3. With a finger, apply upward pressure to the link to the upper throttle valve to remove any slack. Tighten the screw on the upper lever.<br /><br />4. Repeat step 3 for the lower throttle valve.<br /><br />5. Recheck step 1. If the three throttle valves do not start moving at the same time, repeat steps 2., 3. and 4.<br /><br />To set ignition timing you would need a timing light and the manual.<br /><br />Good luck.

 

[Beaux]

Re: Syncronizing Butterfly Valves in 70 Johnson

17isme-<br />You sure the problem is your carbs being out of sync? The most common causes of your problem is an incorrectly propped motor or dirty carbs... also have you checked for fuel restrictions,etc? I adjusted my 60 johnny just as described above, but it did very little to improve top end rpms...did however make it much smoother from idle to plane (which was my problem that I was having) as all three carbs opened and transitioned at same time. If need to sync butterfly valves, I would think you need to do the entire sync and linc, you will need a manual. Good luck

 

[sloopy]

Re: Syncronizing Butterfly Valves in 70 Johnson

Hi JAZZ!<br /><br />if all else fails and you are confused first remove the carb covers (plastic box things if it has them) then on the sides of the carbs there are these little sturdy rods going from one carb to the other, that way when the top carb opens its butterfly valve the rods push open all the others! sometimes these rods are bent in the middle and no matter how hard you try to fix it, it will not work, so if all else fails make shore the rods are strait, if not go look at Hootymans advice Good LUCK!