Inline 6 150hp Link&sync advice!

[Lone Duck]

Re: Inline 6 150hp Link&sync advice!

Yes the pointer on the distubertor , dots on the flywheel, and center of the crankshaft have always lined up when I have done a link and sync on them. If you line up every thing as it should be then the timming marks will show the TDC mark and pointer more adavanced that what is shown. The belt timming being off one tooth will also make a diffrence of where things should sync up . JMO
Oldman570

correct!! The last line in my previous post is wrong. I should of said ( Then you use your dial indicator and set your pointer to the 464 mark. Sorry about that!

 

[Chris1956]

Re: Inline 6 150hp Link&sync advice!

Sour, The timing belt looks to be close enough. They are mostly a half tooth off. The marks on the dist cap and dist body are made by a Prev owner, because he was too dumb to locate the dist cap properly. It only goes on one way, unless something is broken.

21* BTDC is the proper max spark advance (not 22*). The left side of the decal is indeed BTDC.

The idle timing is to synch the proper timing setting with the carb. After the carb is closed, the timing will naturally be retarded as the throttle closes more. So the 10* ATDC could be right, as I have never measured it. The proper timing is that the carbs just start to open at 4-6* BTDC. Make sure that is set and locked in.

I never thought a '73 Merc IL6 would have a timing pointer. I thought those came out later.......But it is your good fortune, because it is a better system than the older one. Make sure to set the timing pointer properly. Start by synching it at the .464 mark.

 

[Lone Duck]

Re: Inline 6 150hp Link&sync advice!

Sour, The timing belt looks to be close enough. They are mostly a half tooth off. The marks on the dist cap and dist body are made by a Prev owner, because he was too dumb to locate the dist cap properly. It only goes on one way, unless something is broken.

21* BTDC is the proper max spark advance (not 22*). The left side of the decal is indeed BTDC.

The idle timing is to synch the proper timing setting with the carb. After the carb is closed, the timing will naturally be retarded as the throttle closes more. So the 10* ATDC could be right, as I have never measured it. The proper timing is that the carbs just start to open at 4-6* BTDC. Make sure that is set and locked in.

I never thought a '73 Merc IL6 would have a timing pointer. I thought those came out later.......But it is your good fortune, because it is a better system than the older one. Make sure to set the timing pointer properly. Start by synching it at the .464 mark.

Close enough??

 

[sourbsted]

Re: Inline 6 150hp Link&sync advice!

I want to try to move that dizzy cap back and forth and see if it makes a differance. It's like the motor has a invisable vacc advance!

 

[Lone Duck]

Re: Inline 6 150hp Link&sync advice!

I want to try to move that dizzy cap back and forth and see if it makes a differance. It's like the motor has a invisable vacc advance!

fair enough. But do not skip the systematic checks as out lined in lync & sync manual .

 

[sourbsted]

Re: Inline 6 150hp Link&sync advice!

I'm trying to find an "imperial dial indicator"they have one here at my work I think. How do you keep it stable in the spark plug hole? I'll have to find a way. The genuine mercury would have a thread I spose.

 

[mercurymang]

Re: Inline 6 150hp Link&sync advice!

Just out of curiousity, does your flywheel only go on one way? Mine is splined but it has one area where the splines "double up" acting like a keyway which allows the flywheel to only go on one way. This means that I don't need to use a dial indicator to find TDC.

 

[Lone Duck]

Re: Inline 6 150hp Link&sync advice!

yes!! It is threaded into the spk. plug hole. I boats store should have one. Or if you search amarine supply store you should find one. Also contact supplier for Imperial dial indicator some outfits supply a kit to attach to the dial gauge, it has two different size threaded sleeves that are held on the indicator with a set screw.

 

[Lone Duck]

Re: Inline 6 150hp Link&sync advice!

Just out of curiousity, does your flywheel only go on one way? Mine is splined but it has one area where the splines "double up" acting like a keyway which allows the flywheel to only go on one way. This means that I don't need to use a dial indicator to find TDC.

That is correct you don't need a dial indicator to find TDC you can use a wooden dowel to do so. By moving fly wheel back and forth and feeling the dowel you can tell where it gets to it's greatest height which is TDC of the piston. How ever ! you need the dial to find .464. of the stroke.

 

[Chris1956]

Re: Inline 6 150hp Link&sync advice!

If you do not have a dial indicator, you can still find .464" with a steel ruler, or better yet a caliper. Set the motor to TDC using a screwdriver or similar. Now measure from spark plug hole to top of piston with ruler. Add .464 inches to measurement, and save the sum. Now back down flywheel (CCW) a quarter turn. Stick ruler into spark plug hole up to sum (in inches), and turn flywheel CW until piston just touches ruler. Now adjust timing pointer to read .464" BTDC.

 

[Chris1956]

Re: Inline 6 150hp Link&sync advice!

Duck, When I said "close enough", I meant that the timing belt is probably installed properly. The teeth positively locate the pully, but it can be 1/2 tooth off, and be fine, as there is no way to get it closer. There is a section in the OEM manual that states that if the motor is tough to tune, and the pully is 1/2 tooth "off", move it 1 tooth and it will be 1/2 tooth "off" the other side.

Sour, The distributor cap should positively fit, with very little play. If there is play, you need to inspect the cap and see why. Maybe a piece of the plastic chipped off?

 

[Lone Duck]

Re: Inline 6 150hp Link&sync advice!

Duck, When I said "close enough", I meant that the timing belt is probably installed properly. The teeth positively locate the pully, but it can be 1/2 tooth off, and be fine, as there is no way to get it closer. There is a section in the OEM manual that states that if the motor is tough to tune, and the pully is 1/2 tooth "off", move it 1 tooth and it will be 1/2 tooth "off" the other side.

Sour, The distributor cap should positively fit, with very little play. If there is play, you need to inspect the cap and see why. Maybe a piece of the plastic chipped off?

Cris I have the merc service manual #90-86134-4 printed in 91 . Don't say what you suggest. Makes sense thank you.

 

[sourbsted]

Re: Inline 6 150hp Link&sync advice!

I want to have a good look at this dizzy cap. If the rotor button is striking number 1 pole in the dizzy cap at the wrong time, then that would explain why the I am not getting BTDC on idle. Instead I'm getting ATDC 10 degrees. It has a fair bit of slop in it!

 

[mercurymang]

Re: Inline 6 150hp Link&sync advice!

I still think that timing gear is off. Can you take a picture of it with your camera drawing a line between the center of the distributor and the crank.

 

[sourbsted]

Re: Inline 6 150hp Link&sync advice!

dear oh dear

The primary pickup had a broken join in it. It was on the opposite side to the bolt in the picture,
The washer on the bolt was getting stuck on the broken join!!
I was unable to move the "primary pickup plate" enough, so when I raise the RPM to try achieve BTDC setting it didn't work.
So so now I have it set on BTDC 2 degrees. I couldn't go any than 2 degrees cause the pickup plate run out of adjustment..
Mercury manual states:
-73 inline's 2-4 degree's BTDC
-74 inline's 1-3 degree's BTDC
-75 onwards mostly 4-6 BTDC..

Hopefully all is good now..
Thanks for everyones help! This forum is
Lifesaver!