Timer pointer adjustment on 86 Merc. 150 hp. blackmax

[duhn]

I am trying to do a link and sync. The first thing the Seloc manual tells you to do is adjust the timer pointer. Has anyone done this before? The instructions do not make any sense! What is the purpose of turning the motor counter-clockwise? There are dozens of models that have different instructions. Mine is on page 6-37, model 150 serial # 5203429 and above.

 

[uncle bert]

Re: Timer pointer adjustment on 86 Merc. 150 hp. blackmax

Turning the flywheel counter clockwise will move the crankshaft and pistons. You need to get the # 1 cylinder at Top Dead Center. I usually take out the #1 spark plug and put in a long screwdriver in the hole. When you move the flywheel you will notice that the screwdriver either moves in or starts to come out. You want the piston to be as close to the hole as possible Top Dead Center so you want the screwdriver to be pushed as far out as possible before it starts to travel back in. That way you know it is at TDC. The pointer has to come off to remove the flywheel in some cases so they are telling you have to install it. The book should tell you what timing make your motor should be at. i.e. 6 degrees 8 degrees 0 degrees. Once the fly wheel is at top dead center you can then install the pointer to point to desired degree.

 

[duhn]

Re: Timer pointer adjustment on 86 Merc. 150 hp. blackmax

Wow! Thanks for the quick reply. The manual has you using a dial indicator, which I am using, to find TDC. After TDC is found with the dial indicator, this is the confusing part from the manual....slowly rotate the flywheel counter-clockwise until the dial indicator needle is approx 1/4 turn beyond the .462 mark....(My flywheel happens to have a .462 mark on it)

What does this mean? When you're dealing with an accuracy of .462 degrees, why do you turn it approx 1/4 turn? how accurate is that? Is this 1/4 turn refering to the flywheel or the needle on the dial indicator?

 

[j_martin]

Re: Timer pointer adjustment on 86 Merc. 150 hp. blackmax

Wow! Thanks for the quick reply. The manual has you using a dial indicator, which I am using, to find TDC. After TDC is found with the dial indicator, this is the confusing part from the manual....slowly rotate the flywheel counter-clockwise until the dial indicator needle is approx 1/4 turn beyond the .462 mark....(My flywheel happens to have a .462 mark on it)

What does this mean? When you're dealing with an accuracy of .462 degrees, why do you turn it approx 1/4 turn? how accurate is that? Is this 1/4 turn refering to the flywheel or the needle on the dial indicator?

You turn it CCW about a quarter turn, which will be over an inch. Then you put in your dial indicator, zero'd to TDC, and slowly turn the wheel CW till you get to .462 inches. Then you move the pointer so it is over the .462 mark on the flywheel. That mark represents .462 inches before TDC.

You can only feel TDC within a degree or so, because the piston stalls at the top of the stroke. Doing this, your setting will be as close as your eye is, within a fraction of a degree.

I made an adapter that holds a cheep digital caliper by gutting a spark plug and welding a metal tab to it. I put it in the cylinder, rotate past TDC, which will push the dial indicator to that position, hit the zero button, back it down, push the indicater back in, then come back to .462. It takes about a minute, including finding a couple of tie wraps to jury rig the caliper.

hope it helps
John

 

[j_martin]

Re: Timer pointer adjustment on 86 Merc. 150 hp. blackmax

The reason accuracy is so important. The difference between 25 degrees and 27 degrees is the difference between extreme performance and a grenade.

hope it helps
John

 

[uncle bert]

Re: Timer pointer adjustment on 86 Merc. 150 hp. blackmax

Man I would think it is still to tune your dial indicator. If im correct you are trying to set you dial indicator right? So if your motor is at TDC then I would adjust your pointer at whatever degree the book says so. Because after you get the motor started you will then have to tune it to the degree that the book tells you to. From what in understand you want to get the pointer in the correct position before you start trying to time it in right?

 

[j_martin]

Re: Timer pointer adjustment on 86 Merc. 150 hp. blackmax

The timing pointer is usually mounted on the plastic flywheel cover, which could move quite a bit. It is adjustable. the .462 procedure is to accurately place that pointer. Then a timing light is used to set the actual timing.

hope it helps
John

 

[duhn]

Re: Timer pointer adjustment on 86 Merc. 150 hp. blackmax

"Slowly rotate the flywheel counter-clockwise until the dial indicator needle is approx 1/4 turn beyond the .462 mark."

These are words directly from the Seloc manual.

What does that mean????

 

[j_martin]

Re: Timer pointer adjustment on 86 Merc. 150 hp. blackmax

Again the procedure.
1. Mount a dial indicator of some kind that reaches into the spark plug hole and can touch the piston.

2. Rotate the flywheel till the piston reaches it's highest point.

3. Zero your indicator at that point.

4. Rotate the flywheel ccw till the piston if further than .462" down the hole. (proc 1.4 turn)

5. Rotate the flywheel cw til the indicator is at .462"

6. Set the pointer on the cover to the .462 mark on the flywheel.

hope it helps
John