65' 4.9l timing gears inquiry
 

I bought an old merc f100 off of a farmer. He parked it because he thought he'd broken the timing chain. However I know they use gears. When I crank the engine it will spin fast and then hit "hard spots" as if it is indeed out of time. My question is, is it possible it's jumped a few teeth? How big of a job is it? And will I need any special tools other than obviously gear pullers.

Thanks in advance for any advice!

On my 88 4.9l all I had to do was pull the fan and harmonic balance. You'll need the puller for the balancer and that's all I needed

So update. A friend suggested that I bring cyl 1 to TDC and check on my points if it's lining up with the firing position for cyl 1 ( sorry my terminology is a little lacking). So anyways, I found that it was lining up, or atleast pretty darn close. So I reinstalled my cap, poured some fuel down the carb and tried cranking it. Nothing. However the hard spots had quit occuring. I then pull a plug and check for spark. None. So I pull the cap off and try cranking while watching and and rotor had quit turning. I'm able to turn it very easily by hand.

So my question is, is it possible that just the gear at the bottom of the distributor is broken? If it was intact, yet the cam timing gear was broke would there not be some fairly decent resistance when I turn the rotor by hand?

I'll pull the distributor tonight, but what precautions should I take before doing so to ensure when I reinstall a new one I'll be able to line it up perfectly? Simple as bringing cyl 1 to TDC? I'm half lost here fellas, so I appreciate any advice!

In case anyone was curious, it turned out to be the distributor gear shear pin. Replaced it, tossed the distributor back in after marking my N. 1 cyl and she fired right up. Engine actually ran pretty good for not having yet put a timing light to it. I actually drove it from location to my farm. Not bad for a 65' mercury purchased for 400 dollars!