1974 Merc 65hp - timing belt help

[fishysmell]

I noticed a few cracks in my timing belt. I already have a new belt, and have both an aftermarket manual and a shop manual. I think I understand the procedure pretty well, but I am curious about tools. Can I use any type of universal puller that I might find at an auto parts store, or do I need to find the specific flywheel puller and flywheel holder that the manuals say to use?

Also, I'm assuming I'll need to re-set the timing, and I've read through the process...it seems pretty straight forward, except that my flywheel no longer has the timing decal. There are, however, a series of punch markings on the flywheel (4 to be precise) that appear to be under where the decal was. Can I use these? And what does each represent?

Lastly, I don't have a tachometer, but there is an input for one on the remote control unit. Will any tachometer work as long as the plug matches the receptacle on the remote control? Or is this another specific piece of equipment I need to track down? I think I need a tachometer to correctly time the motor (unless you guys know of some cool trick that I am unaware of).

Too long, didn't read version: 1) can I use any puller on the flywheel? 2) How can I set timing without flywheel decal? 3) Will any old tachometer work?

(1974 mercury 650, 65hp, 3 cyl, ser#4048369)

 

[Laddies]

Re: 1974 Merc 65hp - timing belt help

I would only recommend the puller that screws into the center of the hub but am sure that you will be told to just remove the flex plate from the center hub, whatever. As you know the timing decal is NLA and so is the timing pointer, so if you look on the outer edge of the dist. drive pulley you will see a small raised boss (bump) if you line the boss with the mark cast in the dist mount and then remove the flywheel (however) being careful not to move the crank position till the belt is back on you will be close as you have not changed the timing only the belt, to time the engine you will have to turn the #1 piston to TDC and make a mark on the block and flywheel, when mark the flywheel again at 23 degrees and time it with a lite. As far as a tach you will have to move the brown sencor wire from the switch box to either one of the 2 yellow terminals on the rectifier and then you may install any alternator powered tach.

 

[fishysmell]

Re: 1974 Merc 65hp - timing belt help

Once again Laddies, thank you.

edit: I did find the original pointer in the pull rope bag! So I got that going for me.

Double edit: after re-reading your response, I'm wondering if just removing the flex plate is an easier and/or cheaper alternative to removing the entire flywheel. Will I have enough access to remove and install a new timing belt?

 

[fishysmell]

Re: 1974 Merc 65hp - timing belt help

I know it's bad form to bump my own post, but I added a question as an edit, and I didn't realize it wouldn't bump it.

 

[Laddies]

Re: 1974 Merc 65hp - timing belt help

I have never disassembled a flywheel except to replace a flex plate a Mercury don't recommnded it so I don't know.

 

[Laddies]

Re: 1974 Merc 65hp - timing belt help

I have never disassembled a flywheel except to replace a flex plate as Mercury don't recommnded it so I don't know.

 

[fishysmell]

Re: 1974 Merc 65hp - timing belt help

Well, I'm not adventurous enough to try something when someone with experience is warning me not too. So I ordered a flywheel puller, and went ahead and ordered a new water jacket cover gasket (recommended in a previous post), and will pull my first flywheel when I receive the tool. Wish me luck, although with the help I've received I shouldn't need it. [sound of fishysmell knocking on wood]

I'm curious...I haven't read or found anything about putting the flywheel back on. Is there anything I need to know? Is it totally straight forward? (i.e. put the bolt back on and tighten to specs?)

At any rate, thanks to everyone for all the help. Once this is done successfully, I'll be dropping the lower unit to try and figure out what's wrong with the rear lock mechanism. So you're not rid of me yet.

 

[Laddies]

Re: 1974 Merc 65hp - timing belt help

Your flywheel is keyed so you will have no problem, the trouble these guys have is they remove the bolts and don't mark the wheel and then don't know which way to reinstall the pieces.

 

[fishysmell]

Re: 1974 Merc 65hp - timing belt help

OK...here's an update. Got the water jacket cover off, cleaned it up, replaced the gasket, and promptly broke one of the bolts trying to torque it to specs. I know, I was warned. Decided to replace all bolts and broke 2 more trying to torque them. Replaced those and put them on till it felt right. I'm not sure what's up with breaking new bolts, but I will listen to all advice given.

Getting the nut off the flywheel has been driving me crazy today. I've tried everything short of using air tools. So, no luck getting the flywheel bolt off today. The service manual shows some happy chap easily removing the flywheel with a couple of specialty tools...one of which looks like it holds the flywheel in place while removing it. I've searched by part number but have not found it. I guess I should find a way to use an impact wrench on it...neighbor, rental, whatever I can find. I guess that's what I'll do unless someone here has a way to break this nut clear that I'm not seeing.

At any rate, progress was made and I appreciate all the help I have received so far.

 

[James R]

Re: 1974 Merc 65hp - timing belt help

Need to chase the threads with a tap, wire brush and apply anti sieze to the bolts when you reassemble. Use an impact air gun with the correct size socket to remove fly wheel nuts and to refit them.

 

[Yepblaze]

Re: 1974 Merc 65hp - timing belt help

From my experience a 1/2" air impact gun is a must have for this job.

 

[MadProps]

Re: 1974 Merc 65hp - timing belt help

I have had a couple that my impact wouldnt budge

had to resort to a breaker bar with a 4ft length of pipe to give me leverage

 

[fishysmell]

Re: 1974 Merc 65hp - timing belt help

Am I going to have this same issue putting the flywheel back on? Should I use an impact gun for that too? How can I be sure not to over torque it?

 

[Laddies]

Re: 1974 Merc 65hp - timing belt help

It's usually possible to use a large screwdriver as a stop between the starter bendix and the ring, sometimes it requires 2 people to do it but should work.