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1969 Mercury 20hp

R

rt500

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Hi, new to site..!

I just dragged home merc 200 (20hp) tiller, I've got a lot of experience with 2stroke motorcycles and sleds... Never owned a small merc or worked on a outboard, always wanted too, though. Ok, the dream is alive and I've go til first week of may to get this thing going.

Compression - good
carb - clean/good
fuel delivery - clean
shift linkage - good

Spark - low is bright, big and blue
- upper, non existent, I switched plugs around and top is not delivering spark. My questions are this -

are the two coils the same..?
how do I get the fly wheel off..?
do I need to take it off..?
if and when I get the fly wheel off, should I be looking for any common problems..?

Ok, just wanted to thank you for reading and replying inadvance... from my previous experience being a newbie on forums has been really helpful.

Cheers

rt500
 
You have the points ign. under the flywheel or the switchbox on the side? Or the mag under the flywheel?
One cold coil usually means the box it bad on that output.
 
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Switch box, ok... where is it, what identifies it.? Is it repairable or do guys just replace it.

Points hmmm, adjust, clean and/or replace and spark could come back if coil is good. Maybe its not the coil, I've seen this on old 2 stroke motorcycles should have thought of that.


thanks

rt
 
Pull the flywheel using 2 or 3 holes near rhe crankshaft for that purpose.--------------You will find 2 coils , 2 condensers and 2 point sets--------------Inspect and repair as needed.
 
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Welcome to the world of Old Mercs, an obsession that will grow on you!

A good three jaw puller will get the flywheel off, and under it is a good mag called a Phelon. If you're lucky, all you'll need is to clean/ gap the points and spark will return. If not, try swaping the condensers and see if that works. If still no luck, replace the coil.

You might want to join us on John's Old Merc Forum. Lots of us Mercophile nuts on there!

Jeff
 
a quick update, coils are to spec on both primary and secondary circuits... noticed, the stator plate in the back has one striped out connection and wires were lose.. Since I'm so far in I'll check, clean and set the points. If some can tell me point gap at TDC.

also, thanks for all the great feedback..!

Alittle history, grew up on Okauchee Lake, WI and Tin Tinus from Tinus marine was our friend and neighbor, he raced mod vp class, sleds, etc... So it was common for me to ski and do speed runs with him.. When an evinrude guy pulled up, he'd hand me a life jacket and bug googles and it was on.

I even remember back in 79 helping him out a cone on the lower unit of his very 175 black max. 17ft baja, fun time. Huge influence on my life he was..!

kimcrwb1, thanks I'lll do inspection and if I don;t get spark may need some of those parts.

great site..!

rt
 
ok, back in the shop... need help clarifying which is what.

1. got tdc, using caliper, then ccw flywheel to .375

2. now which is the full throttle adjust screw..?

3. which item is carb lever

I'm close here, can smell it.
 
Progress, I have good bright blue spark on both cylinders..! Carb is clean and have compression.. Waiting on a few items.

1. Primer bulb, came with nice tank but primer bulb was shot.
2. Having the recoil housing welded because it was cracked and broken in another spot, recoil moved around while pulling it over.


I'm sure there's something else... The goal is to know it fires, running it briefly in test tank to confirm its potential.. Then I'll check impeller, finalized timing and put it all back together for some light testing on the river here(when ice melts of course).

As a good rule, I never invest anything into a motor until I shake it out and prove its a runner. Once I have that foundation, I can dig deeper into it to making it a reliable old merc.

Thanks to everyone that contributed, great site..!

rt
 
Hello everyone, looking for some carb assistance here... I've been pulling and pulling tonight, its 64 degree and I thought fresh gas and we'll have something here.. Not so lucky.

got spark, fuel flow to float bowl is good. I'm not getting any gas to the plugs..?

1. float bowl is getting gas, not sure how/if float height can be set..?
2. wondering if float valve is bad, seen them go bad on old 2 stroke bikes
3. what is the setting for the top air screw, (I think its an air screw, has long thin shaft that goes down into carb body, has port on one sidem like it scavenges air/gas)
4. all parts, jets, breather holes and ports in the carb have been cleaned and blown out.

Its got to be something simple... thanks.

rt500
 
120psi per side, pulled fly wheel off and crankshaft bearing seal (just inside points) was blown off/up... I heard/read this is common but would this cause motor to run improperly..? compression was still good at 120psi.
 
Ok, since I still don't have a manual for this motor, I have to ask one more question..? What's the part number for the crankshaft seal (1969 merc model 200 20hp)...

Jeff, you mean the clear 2 part epoxy you mix up..?

Thanks

rt
 
Hey, I just want to thank you all for the quick info... A good forum with good people always restores my faith in humanity.. Man, life is good!

Have a good Sunday!

rt
 
...."..you mean the clear 2 part epoxy you mix up..?"

Yes. Use the non-instant variety--seems to hold better.

Jeff
 
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