Link & Sync ? 1994 Johnson 150 ? J150ELARV

[MaPaHa]

I?m rebuilding the carbs on this motor because of idle ? takeoff problems and have found at least two concerns that would cause the problem. The biggest problem is one of the O-ring gaskets between the throttle plate and intake is messed up so hopefully this will fix it along with the rebuilt carbs. The Clymer manual says 3 turns out on the idle/air screws but mine were set at 5 out. Which is right?

While checking the throttle and timing sync visually it was not what I expected. The way it is now, the throttle linkage (butterflies) and timing begin moving at the same time when the main throttle control lever is pushed up. I thought the timing was supposed to advance first before the butterflies began to open. I?ve had a 1996 Johnson 175 of the same build since it was new that has never been messed with and the linkage is set to advance the timing before the butterflies start to open. Does this sound normal?

I know it needs to have the entire link & sync performed but would it be better for now to make it closer to what the 175 is doing? I see the difference in the settings on the linkage and it would be easy to make an adjustment to ?mirror? the 175?s settings and begin to advance the timing a little sooner. I just bought the 150 motor so I don?t know the history, but I?m quite sure its run this way for a while where there is more fuel ? air throttle for a given level of timing advance. Once it?s at WOT this would not have an impact because the timing does reach full advance.

Any thoughts in general on timing advance vs butterfly opening?

 

[schematic]

Re: Link & Sync ? 1994 Johnson 150 ? J150ELARV

OIS2000 system, get a manual and do it right. You'll be surprised on the adjustment procedures.

 

[MaPaHa]

Re: Link & Sync ? 1994 Johnson 150 ? J150ELARV

Schematic,

I'm glad to hear you say that I'll be surprised on the procedures because that tells me I've got the wrong manual. When I read through the procedure it talks about several special tools and to be quite honest, I cannot understand the concept of what's going on. I've done linc and sync on old Mercury 6 cylinder 115 HP motors where you use a dial indicator in the #1 cylinder to find TDC and go from there: and don't usually have a problem understanding procedures. My problem is I'm using it this weekend and unless I can find the English version of the link and sync quickly, I'll have to go with what I have.

Surprisingly the motor runs great once you break idle speed and that was before the carb rebuilds, replacing the blown out O-ring gasket between the throttle plate and the intake of the engine and replacing one carb float bowl that had a wood screw in the plug at the bottom of the bowl partially blocking off passage of fuel to the main jet. I'm pretty sure this will make it much better because it had to be sucking air in at least one carb and another one gimped up with a screw. I'm finishing the carbs tonight and finishing the nick-knack stuff tomorrow night.

The motor has been running with the existing sync settings for several years from the looks of it and I'll have to order another manual and wait several days for it I'm sure. I was just looking for any improvement to make now. If you are crazy enough to have two boats, it sure makes it nice to have the same motors so you can compare and swap parts when needed, and that's the only thing that clued me in that the sync may not be right.

What manual should I get and where do you get something better than the ones at the dealerships?

Thanks

 

[schematic]

Re: Link & Sync ? 1994 Johnson 150 ? J150ELARV

Well, you won't get a better manual than the OEM ones. You can find them on Ebay for cheap. I'll be honest with you. I built the special tool they ask for. I used it several times. Once you really understand the concept of Idle timing, max timing and quick start, you realize that all you really need is a timing light. Study the moveable linkage that carries the optical sensor and understand what limits its idle location and max location. Once you understand this, you will be able to determine what adjusts idle and max timing.