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1973 evin 25hp missing bottom cylinder

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Sirrobbythe5th

Contributing Member
Ok so here's the issue, my 73 evinrude 25hp is missing on the bottom cylinder. I ran it, pulled the bottom plug and it ran better, put the bottom one in and pulled the top and it died. I've switched the engine coils by the spark plugs and the same issue.
Now as for everything new, I have a new tank, hose, filter on the hose, rebuilt fuel pump, new thermostat, the carbs rebuilt and all new wires, new plugs.
i set the gap on my points and they open with the "set" mark on the cam hits em. However, the marks on the armature plate don't line up. Now obviously the throttle moves the armature plate "thus moving where the two marks on there are at"
where does the throttle need to be at to set the timing .?
 
I've done a spark gap test awhile ago but I didn't do it in the dark so it was hard to see, but I do remember seeing a spark jump 1/4" on that cylinder. The cylinder I'm having the issue with
 
racerone, but if your setting your timing. So that the marks ( the two marks 180 from each other) on the flywheel falls in-between the two marks on your armature plate....it will change depending on where your throttle is at because the throttle moves the armature plate.....moving where those two marks are....... How am I so lost here
 
Because you do not understand that you are timing the opening of the points relative to the rotation of the magnets.--That is how the spark is generated by the magneto.----The timing of the spark in the cylinder is looked after by the rotation of the magplate.----Please do not over think this.-----It is not the same as the ignition on " grandpa's old 283 chevy " of years ago.
 
Hahaha ok thank you, I'm not trying to over think it here. But the cam or "set mark" is whats physically opening the points as it rotates...and the flywheel is bolted on that..... But In my case, One cylinder opens right when it should... " when the mark on the flywheel is in-between the two marks on the armature plate...But my other cylinder Isn't even close...its like two inches off
 
Time for some detailed pictures of what you have under the flywheel .-----Possibly the wrong set of points ??-What is the 6 digit # on the flywheel ?-----There are some variations here.------Both sets of points should open when mark on the flywheel ( there are 2 marks ) are between the 2 vertical lines on the magplate.---Again you are timing the points relative to the magnets rotating past the heels on the coil.---The rotation of the magneto plate looks after timing the spark relative to piston travel.---------I have done this timing of points since about 1968 so I do have some knowledge here.
 
I am quite familiar with what you have !----Close-up picture of the clips on the points.-The ones that hold the spring to the post.
 
I will when I get back to popping it off. Got new points and condensors today. The guy at the shop said it could possibly be one of my reed valves though!!!!!!
 
So as I was putting the spark plug in the bottom cylinder today it ripped the threads clean out. Could I use a heicoil to fix it? A new head assembly is about 130
 
heres a close up of one of the old points. I replaced the points and condenser today. and finally figured out the timing....didnt get a chance to run it though because of the spark plug issuePOINTS.jpg
 
Ya I adjusted the gap per the mark on the crank. and checked to see when they began to open using a multimeter, with the flywheel on. and they begin to open right when the line on the flywheel is in-between the two marks on the armature plate
 
So I moved the spring on the points to the only other position it could go in. is this correct? Also in the picture you can see how the contacts don't line up perfectly. Is that acceptable ?Points spring.jpg
 
Took the head assembly off today so I could take it in to get re threaded or helicoils put in. I feared I might accidentally get metal inside the sleeve.... ANYWAY are these grooves fine? I didn't see any gouges etc.. Also how should I clean the sleeve and cylinder heads?No head.jpgPiston.jpgPiston sleeve.jpg
 
Now I've been surfacing the head and one thing I noticed was the old gasket says on it NO SEALANT. So when i put the new gasket on should I use the evinrude gasket sealer? Especially since water runs around the piston sleeves and I don't want it to leak into the cylinder??
 
Most new factory head gaskets say ---DO NOT USE SEALER----So if surfaces are clean and flat you do not need sealer.--------The clip on the points is now installed as it left the factory ( post # 25 )
 
The fact is that most folks use way to much sealer !!----This than squeezes out of the joint and plugs things up like small drain passage ways in the block.----This could freeze and crack the block.--------So the good folks have developed head gaskets and other gaskets with a film of sealer put on at the factory.-------Whenever I see globs of RTV sealer on a motor I know that it was not worked on by an experienced mechanic !!!
 
Well needles to say, I'm screwed. I put helicoils where my stripped spark plug was ( bottom cylinder). And when i put pressure on the cylinder I can hear air leaking out of that spark plug.... And they don't make those heads anymore.........
Now i haven't compression tested the cylinders yet..or started it up. But theres defiantly air leaking out
 
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