Re: merc 200 flywheel puller
20 hp flywheels ain't threaded in the middle like the flywheels on bigger Mercs.
Most of the old 20's had (2) bolts opposite each other on the flywheel mounting hub which were meant to be removed for pulling the flywheel. There may even be a decal on the flywheel to identify the bolts.
It's been a while, but I do seem to recall those bolts also came with a lockwasher where the others didn't.
If you find your flywheel doesn't have those specific bolts, you can still pull any (2) bolts opposite each other. When you're done, reinstall these bolts with a drop of red Loctite on the threads, and torque to 24 ft-lbs for a 5/16"-NF fastener.
What you'll need is an automotive-type harmonic balancer puller, or other suitable puller which will allow you to pull with bolts threaded into the (2) vacant bolt holes in the flywheel.
Note that these bolts MUST be Grade 8 or better (Grade 8 has Six hash-marks on the bolt head) or they will likely snap when you're reefing on the flywheel puller.
Once you pull the (2) bolts, loosen the crankshaft nut and back it off until nut is flush with the top of the crank. This'll keep the flywheel from flying off the crank and smacking you in the face!
Then, set up the flywheel puller; run the puller bolts a ways down into the holes to get good thread engagement, then tighten down the center screw on the puller until the flywheel "pops". If you get it real real tight and it doesn't want to go, try pulling upwards with a fair amount of force on the puller screw, then carefully giving the screw a stout rap with no more than a 5-lb mallet. Don't just wail on it, or bang away like pounding a nail. You're just trying to shock the flywheel off the shaft.
That will pop the flywheel in the majority of cases. If it just doesn't want to go, give the center a shot of PB Blaster or other penetrant, let it sit overnight under tension, then try again.
If that doesn't work, apply heat from a propane or MAPP torch (try Lowe's or Home Depot) at the center of the flywheel, and attempt to pull. If it doesn't come loose by then, heat 'er up one more time then spray some more penetrant and let it sit.
I had a big Johnrude whose flywheel was so tight it took a week of soaking and repeated heatings to break free. I sure was glad when it let loose!
Anyway, the little Merc shouldn't give you as hard a time as that, unless it's extremely rusted. Usually they come right off. One last trick would be to hit it with an impact wrench, just use caution 'cause it can shock the bearings. Short bursts would be better than laying on the wrench for 15-20 seconds, for example.
Well, that outgha do it, HTH & G'luck.........ed
