1986 Mercury 60hp Flywheel/timing

[choogyddad]

I recently bought my first boat! It has a 1986 Mercury 60hp motor on it. The motor appears to be in great shape, and the old man I bought it from fired it up and let it run. Anyway, some of the wiring is cracked coming out of the stator. I removed the flywheel and pulled the stator off.

I have a .pdf manual that covers 60hp Mercury, and supposedly my year. The thing that is throwing me off is that the flywheel on mine is different than the one pictured in the manual, and the timing marks are a bit different. The manual says to set the timing to .459 BTDC, and the flywheel pictured has .459 scribed in it. My flywheel has 464 scribed in it. I am assuming that this means I want to set timing to .464 BTDC. I want to be sure this is the correct assumption. Also, I am not 100% sure what I need to do to actually set the timing.

My plan now is to use a dial indicator in cyl 1 to find .464 BTDC, and then install the flywheel so that the pointer on the motor is aligned with the 464 mark. The flywheel pictured in my manual is not the same as the one on my boat. Any help with this would be greatly appreciated.

 

[mercurymang]

Re: 1986 Mercury 60hp Flywheel/timing

I'm pretty sure the whole .464 is meaningless in your situation. That is just a mechanism for the lining up the flywheel on some older mercs that did not have keyways or alignment marks. If you flywheel only goes on one way, then all you need to worry about is your idle timing and your max timing.
Someone please correct me if I am wrong but I am fairly sure this is correct.

 

[choogyddad]

Re: 1986 Mercury 60hp Flywheel/timing

Ok, thanks for the information. I guess basically, this is just a mark on the flywheel for reference. I rigged up the below tool to help find TDC and 464 BTDC. I took a Harbor Freight Dial Indicator that I had laying around and mounted it in a spark plug that I cut the end off of. I had to drill it out a little bit, and then I used some 2-part epoxy to mate the two for life .

I found the idea on a 2-stroke motorcycle website, after I looked up the mercury part number and about had a heart attack when I saw the $150 price tag.

 

[mercurymang]

Re: 1986 Mercury 60hp Flywheel/timing

Ok, so you're flywheel doesn't have a keyway or a special splined tooth that allows it to be installed only one way. In that case, then yes you will need to set up first before you adjust your timing.

 

[CowboyUp58]

Re: 1986 Mercury 60hp Flywheel/timing

I agree with Mercurymang the 464 nothing to worry about only TDC. Make sure your Pointer is lined up with the TDC 0 after you remount it if you didn't check it before you removed it. You may have to rock it back and fourth a bit just to make sure its dead nuts. Mine was off 4 degrees (The Pointer) before I removed the Flywheel. I have the same motor the flywheel is splined to only aline one way. Have the same problem, Wires dried and cracked and got rubbed bear under the flywheel older Mercs famous for that Ive read. As far as the 23 degrees Ive been told set it at 21 degrees not matter what the sticker says due to today's gas.. Working on mine too I'll let ya know how it is going when I'm done Have to do a link and sync first..

BTY I did the same Harbor Freight spark deal too ya just beat me to the post of the idea. They same great minds think alike lol Good one!

Cowboyup58

 

[choogyddad]

Re: 1986 Mercury 60hp Flywheel/timing

Thanks for the replies. It's interesting that they ask you to set the timing indicator at .464, especially when all timing is based on relation to Top Dead Center. I'm not sure I understand the motivation there. I saw another thread where a guy asked the same. All of the answers were conjecture.

I think, like you said, I am going to set the flywheel at Top Dead center, and then spin the crank until I get to .464 on my dial and check the marks against the pointer.

 

[mercurymang]

Re: 1986 Mercury 60hp Flywheel/timing

I agree, the whole .464 thing threw me for a loop when I started out. It really seems to confuse the the issue. Relating to what choogy said, I too set my max advance to 21 as opposed to 23 due to ethanol based on several recommendations on this site. I have had no problems so far.

 

[ShowMeGuy]

Re: 1986 Mercury 60hp Flywheel/timing

View attachment 201061

21 Deg is what I have mines set at as well.... BTW.. I looks like tweety bird approves the Dial caliper customization... Great Idea.

 

[choogyddad]

Re: 1986 Mercury 60hp Flywheel/timing

I run everything by Admiral Tweety...

 

[choogyddad]

Re: 1986 Mercury 60hp Flywheel/timing

Just to button up the thread so to speak, I ended up seeing the flywheel at TDC. I took the boat over to showmeguy's house to get the timing set. The idle timing was pretty much spot on at 4 degrees ATDC (Manual recoomends 2-6). Next we checked the max advance timing, which was fairly far before 23 degrees BTDC. I decided to set the timing at 23 degrees BTDC, as that is very prominently marked on my flywheel. We put the muffs on and the boat fired right up! Then yesterday we took her out to the River to test her under load, and she did fantastic!!! No issues at all. Thanks Everyone!