Carb rebuild question/problem

[hertel11]

Ok. So where do I get the factory manual and how do I go about performing the Link & Sync? 2005 Johnson 40 hp Model J40PLSOC. I have a fishing trip planned for Apr. 27 so I'm really hoping to get this motor back up to tip top shape before the end of March.

 

[hertel11]

**I found this procedure for adjusting the carbs. Is this what I need to do? Also, the starting procedure descried above is what I always do but what about if that doesn't work the first attempt?



Carb Needle Adjustments For Asorted Carb Variations by Joe Reeves July 2nd, 2006, 06:51 PM

these adjustment are for the older engine. 1980 and earlier, and the current small hp ob's. not for fixed jet outboards.


(Carburetor Adjustment - Single S/S Adjustable Needle Valve)
(J. Reeves)

Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.

Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.

Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

Note: As a final double check setting of the slow speed valve(s), if the engine has more than one carburetor, do not attempt to gradually adjust all of the valves/carburetors at the same time. Do one at a time until you hit the above response (die out or spit back), then go on to the next valve/carburetor. It may be necessary to back out "all" of the slow speed adjustable needle valves 1/8 turn before doing this final adjustment due to the fact that one of the valves might be initially set ever so slightly lean.

 

[hertel11]

Also, I'm sure this is important and may be the cause to my inconsistent rpms. My screw to my throttle cam part # 0314136 broke while reinstalling it. I got the broken part extracted fine but can not get an exact replacement until about a week which I already ordered. Just for the sake of seeing if the motor would run I used a lag bolt from the hardware store. The proper part is 1/2" on the lag I believe but has 1/4" threads and the one I got at hardware store is just 1/4" all around. Could this potentially be the cause of the rpm issue at throttle in neutral? Would 1/4" wiggle room on the throttle cam cause a lot of inconsistency? **I know what I'm doing is not the exact proper procedure but this is my first boat and motor and I'm trying to learn everything by myself. I will wait until my throttle cam screw comes in to do anything else but I just want your expert opinions.

 

[Silvertip]

Linkages are critical and yes - a 1/4 inch error can make all the difference. Remember, carb linkages, ignition synchronization with carb opening is essential for proper idle, transition to midrange and wide open throttle operation. Both carburetors need to open and close at precisely the same time. Idle mixture adjustment also controls the transition from idle to part throttle. Too lean and the engine stumbles on acceleration. To rich and it will idle poorly, and likely load up and stall. Again -- you need a "factory service manual". You might make a trip to your local library to see if they have one. It is all explained in detail.