1150 Link & Sync Question

[jakec]

I did not grease the shaft or oil seals, I put them on dry. but the shaft was clean. Is it worth taking it all apart to check? I have always put on oil seals dry on motorcycles.

 

[jimmbo]

Grease, in a very thin layer, should be applied, to the splines, to prevent corrosion from welding the Shafts to their respective partners, making it very difficult to separate in the future.
One Caveat though, only grease the Splines, DO NOT put any grease on the Ends of the Shaft(s) as it could prevent full Insertion of the Shaft, and/or put stress on the crankshaft by forcing it up
As for the 2 Shaft Seals under the Water Pump, Common Sense would have the upper installed to best seal against water pressure, and the Lower installed to best seal against the gear oil. Thus they would be Spring/Lip Side, closest to what they were try to keep from getting out.

 

[jakec]

I have applied to the splines only because I was aware that the hydraulic property might prevent it from inserting easily. I will clean up and remove excess grease though before trying again. And I agree with what you said about the seals and their direction. Funny that these youtube videos all show them backward. Certainly cause a lot of panic for me last night haha.

 

[jakec]

Ok, good news. I got the lower unit on. What really helped was using ratchet straps to hold it in place so I wasn't in such a rush. Then I jiggled the crankshaft and it popped in.

I got it started up (about 4 seconds press on starter) and it peed after a few seconds. It was idling nice and low with the fast idle lever halfway (tach not hooked up). If I let off the fast idle lever all the way, it would die.

Should the engine idle with the butterflies totally closed? I would assume not and that would mean my throttle cable needs to be adjusted to have less range of motion? also my air screws are currently 2 turns out (planned to turn them in on the water).

Also I don't have the shifter linkage hooked up so I tried putting the main throttle lever forward to rev up, but there was no response. The throttle only reacted to the fast idle lever. I walked over and removed the throttle cable and was able to rev it up by pulling on the arm.

 

[jimmbo]

Yes on these engines the Butterflies are completely closed at Idle. Cable adjustment is done after the Idle Speed is Set. Throttle Cable has to be unanchored for the Linkage to move freely, allowing the Speed to be set. Idle speed is determined by the Spark Timing, and that will vary depending on the load on the engine(Different Props will affect it). Once the Idle speed set, then the Cable Length is adjusted to provide a bit of Preload against the Idle Speed stop. Too much Preload and the control is hard to shift, too little and Idle Speed can be inconsistent. Yellow arrow points to where the Anchor Point is and where the Cable Length is adjusted. As for the Lack of Throttle Cable movement from Control Box, the first 50 degrees or so of movement are strictly for Shifting, and then the throttle cable will start to move

Air Screws?

 

[jakec]

When I did the link & sync I did add preload to the throttle arm with the cable once I'd set the idle advance by the benchmark 4-6*.

Since my engine wont run now with butterflies closed, are you saying the first thing I should do is advance the spark until it idles?

If I have a heavier prop/higher pitch do I need a higher idle speed or it will die when you put it in gear?

I guess mercury calls it the idle screw but I was calling it and air screw, as backing it out allows more air and a higher idle, correct? that's how it is on many motorcycles. It's the pointed screw with a spring around it.

BTW I don't have the throttle stop screws on the main arm (red arrow). My arm doesn't have threaded holes for them either.

 

[jimmbo]

As I said the timing is what determines the Idle Speed, as the Butterflies are supposed to be closed.
Again I said that a Different Prop can load the Engine Differently and could require a resetting of the Idle Speed
These engines do not have an Adjustment to vary the amount of Air entering at Idle
I never said your Idle Speed was set at the Red Arrow, that pic, the only one I had was of a later ADI(distributor less) motor, but the Cable Anchor Point is the same. Your Idle Speed Adjustment is up by the Distributor, along with a few more Adjustment Screws. If you were using a Manual appropriate for your engine, that would be shown, along with an explanation of the Process

 

[jakec]

Ok, I just raised my idle using the idle screw and then adjusted the cable for preload. Tomorrow I will do the on the water settings. Sorry, I've never worked on something with a distributor before so what does what is confusing to me.

I found a really useful explanation of the procedure I will do tomorrow, post #2 Link

 

[jimmbo]

The timing is advanced to increase engine speed, then as it reaches a certain point of Advance, the carbs open a bit, then after the timing is fully advanced, further movement of the throttle opens the carbs fully. Once the engine reaches higher RPM, the throttle can be pulled back and this closes the carbs somewhat, even almost closed, engine speed only drops slightly, but full timing advance remains, and fuel economy improves. Results are a bit like how Vacuum Advance on old car/truck engine improved economy at speed with high intake/carb Vacuum

 

[jakec]

Interesting. I had no idea you could maintain a high RPM with ignition advance while burning less fuel and oxygen. So far I've been applying all my knowledge from working on motorcycles, which has helped with basic principles, but when it comes to this ignition system it is almost counter intuitive haha.

I have another question, I know its really broad, but the outboard came with a stainless 19P prop, and I'm just wondering if that would be too high? Most posts I see on here people have much lighter boats than mine and they are running a 17P or smaller.

From the brochure my boat weighed 1500 lbs. back in the day but I've added a couple hundred lbs. with the improved stringers, transom, and floor that I built. So I would guess it could be up to 1800. The brochure also only rated the boat for 105 hp haha.

 

[jimmbo]

Being a 77, your engine has a has a WOT range of 4800 - 5300 rpm. A 19 sounds a little long for what you have it on. A lot of boats in my area were running 17" on boats between 15ft and 18 ft. But the only way to know is to run it and see what RPM it pulls at WOT.

My first boat was rated for 90hp. I tested it with a 90hp but, I put a little bigger engine on it when I bought it

 

[Chris1956]

You only need to grease the driveshaft to protect the driveshaft seal from tearing. You grease the splines to allow you to take it apart the next time.

Link and synch sets the carbs to open at 4-6* BTDC. Setting the Idle speed usually is a retardation of the spark, so yes, the motor should idle with the throttle plates closed. Those carbs do not have an accelerator pump, so they must be set a bit rich from optimum idle quality in order to allow acceleration. If you worked on single cylinder motorcycles, you will find the idle mixture adjustment challenging. You must adjust each carb individually, starting from the top carb, testing acceleration after each adjustment. You are done when she will idle reasonably smooth and accelerate smoothly and fast. You will want to adjust the carbs with a fresh 50::1 gas:il mixture.

Carb needles are gas screws. Turning them CCW richens the idle mixture only. At about 1200RPM or higher, they have no affect.

The correct prop is one that will allow full throttle RPMs to be in max RPM range, with typical boat load, at medium trim setting. 19P prop is pretty standard, depending the boat type, weight and size.

 

[jakec]

When I set my idle it needed to be raised, and I believe I advanced the spark pickup at idle to do it (I screwed that stop screw in about 2 turns)? Luckily my motorcycle experience is with 4 cylinder / 4 carb bikes so 3 carbs is nothing

Ok so my idle screws are at 2 turns out currently and today I plan to turn them in with the engine in gear/in the water. If everything 's going good I"ll try the hole shot and see what the prop does.

I need to hook up my tach but I don't have the wire harness with the 3 prong connector, and I haven't been able to find one online. This is the part that goes to the mercontrol unit. I was trying to figure out how to wire it up myself but I can't tell why prongs are which (on the unit) based on the diagram.

 

[jakec]

Would it be G (brown?) connects to SEND (alternator/rectifier?) and F (white) to IGN? And ground to ground of course.

 

[Chris1956]

There is a collar on the distributor, secured by two bolts with 5/16" heads. This collar is about 1/2 way up the distributor body and rotates to set the carbs to open.

So, with spark plugs 2-6 out, installed in wires and grounded, prop off, motor in gear, jumper the starter solenoid to crank the motor with the timing light on cylinder #1. Advance the throttle until timing is 4-6* BTDC. Now check the carbs. They should be closed and just ready to open. If not, adjust the collar on the distributor to make it so.

Advance throttle all the way, and read timing. Timing s/b 21*BTDC. Adjust max spark advance set screw, above distributor to set it properly.

Carbs mixture screws are set 1-1/2 turns open. Install spark plugs, and prop and run and warm motor. Now set idle mixture in gear to smoothest.
Now start to richen carbs one at a time until you achieve smooth acceleration.

On another subject, on MerControl, one slot on 3 slot female plug is horizontal. That is tach signal, with a brown wire. The other two are with ign power and black ground. Spade terminals will work for these prongs. On your motor, the brown tach signal wire may still be attached to the switchbox. This requires a Mercury only tachometer, and it may not be available. The fix is to attach the brown wire to one of the yellow rectifier wires. This allows a universal tach to be used.

 

[jimmbo]

It was in the 60s when Merc moved the Wire off the Switchbox and on to the Rectifier. However, it never hurts to check, just in case someone in the Past changed it

 

[jakec]

So, with spark plugs 2-6 out, installed in wires and grounded, prop off, motor in gear, jumper the starter solenoid to crank the motor with the timing light on cylinder #1. Advance the throttle until timing is 4-6* BTDC. Now check the carbs. They should be closed and just ready to open. If not, adjust the collar on the distributor to make it so.

I'm confused, is this the same/redundant with the normal link & sync, or something additional that I need to do? Because I did this stuff, just "different," for example I set the distributor to spark the #1 plug at TDC and at the exact time the throttle pickup is contacted. Then next step 4-6* and so on. But it was all done static and I never touched the collar on the distributor.

If you rotate the distributor (plastic part on bottom) independent of the rest of the assembly, wont you be invalidating everything else?


Inside the engine cowl, my brown wire is not connected to anything (new harness installed by me. So I should put it on the same post as the Y/R wires to the stator. Can you tell me between the two vertical prongs on the mercontrol, which is the ground and which is ignition?

 

[Chris1956]

If the distributor is set to spark #1 plug at TDC, idle pickup setting is TDC, not 4-6*BTDC, as it should be.

You may not need to move the collar on the distributor. However, if the idle pickup timing is incorrect, you adjust it using that collar. That is the idle pickup setting procedure for the distributor Mercs. The collar is not obvious to everyone, hence my pointing it out.

The distributor cap fits onto the distributor body one way. It should not rotate independently of the distributor body. The rotor is not removeable, as in a car.

The max spark advance, idle stop and throttle stop settings use the set screw on the plate on top of the distributor. These too are part of the Distributor link and synch for Mercs.

As for the slots in the MerControl. You will need to use a voltmeter to figure out the polarity. I just don't remember. The brown wire should be connected to one of the two yellow wires. If makes no difference which one.

 

[jakec]

I think I misunderstood which collar you meant earlier, I did adjust the collar on the top of the distributor which uses two small hex head bolts. I thought you meant the collar which wraps around it like a hose clamp.

If the distributor is set to spark #1 plug at TDC, idle pickup setting is TDC, not 4-6*BTDC, as it should be.

Sorry it's hard to remember, but luckily it's documented in the post, in post #10 I said this,

1. 464 BTDC & set marker (done)
2. 0* TDC confirm pulley position (done)
3. 4-6* TDC set throttle pickup (this is where the spark occurs at the same time as the throttle pickup, done this)
4. Do remaining link & sync steps. (see below)

You should be able to install plate with set screws on it, and set Idle Pickup timing to that 4-6* BTDC, by not moving throttle. Lock set screw. (done)

Advance throttle full. Use max spark advance set screw to achieve and lock at 21*BTDC. (done)

Spark should be at correct time. As for carbs. If she wont run, they are likely next. (rebuilt carbs )

So now after all that, the only adjustment I've made is advancing the idle pickup screw about 2 turns, to allow it to idle with preload on the throttle arm (butterflies completely closed). I used the instructions here Link

 

[jakec]

To increase idle speed, you would adjust the "Idle Stop" on the "Stop Bracket" that mounts to the front of the distributor. Don't touch the "Throttle Stop" or Spark Adv" screws unless you're doing a more extensive tuneup.

I think I'm just confused on how the distributor works still so I thought that by spinning the bottom part (plastic where plug wires go in) I was advancing the spark. But I'm only messing with the screw labeled idle.