This is all new to me. What is an accetable compression reading for th WD3S? Also, what are the two control knobs under the throttle? I got this motor at a garage sale for $12. I figured it was worth that just for display but its all there and I hope to get it running. Any and all help would be appreciated. Thanks.
Here are a few specs on the 3.2 HP WD3S (Merc KD3S equiv). Spec compression is 120 PSI; but anything above 100 would probably be enough to get it running decently. The original spark plug is the J7J, which is NLA. The Champion RJ8C will work, along with the Autolite 303 and the Bosch WR8EC. It should be gapped at 0.025. The knobs which I think you are referring to are a choke and a needle valve to adjust the carb if it is either running too lean or too rich.
Does it have spark?
Like you said, if you can't get it running, it would make a nice decoration. Well worth the $12 either way!
Havent checked for spark yet. Thought it was locked up. Turned out to be a stuck pull cord. Lots of hornets nest too.
Does this thing have a neutral or is it always in gear?
I believe your model is always in gear. I don't think that Mercury introduced the neutral clutch on its models until either that late 40s/early 50s on the Mark series of motors. I have a Wizard WH6 - which is based on the Merc Mark 6 -- and it has a neutral clutch and tiller handle. It is also a HUGE PAIN to work on. Yours is a simpler design and is much more "restoration friendly."
any idea how to pull the flywheel on this motor?
1) Take out sparkplug insert length of rope
sufficient to stop piston before it reachs top of
travel in cylinder.
2)Remove flywheel nut or ratchet
3) Attach flywheel puller to flywheel and screw in
center bolt to apply pressure to end of crankshaft
4) Give end of center bolt one sharp rap with brass
hammer and flywheel pops loose...
Assemble in a reverse order.
Works that way in manual not always in practice.
Older motors often require creative solutions.
not excessive force.