Johnson 9.9 advice

Starboardlean

Seaman
Joined
Feb 15, 2016
Messages
73
1975. Bought a few motors and this is head scratcher, for me anyway. Bought this motor complete with seized powerhead. Lower unit is good. Penetrating oil and wait. Long story short she is free and spinning nicely. Did a carb clean and kit, points/ condensers and plugs. Spark test of approx 3/8 showed nice fat blue fire on both. To the tank we go. Prime up. Pull100 times nary a pop. Compression of 100 top 90 bottom. Tried to get a pop by spray premix,nope. Finally tried ether,nothing.

The compression high enough to at least get a pop??.
The straight ether really baffles me?? Really expected something.

Just think out loud here... I removed head tilted motor to get cylinders perpendicular to ground. Let oil sit on piston. Of course it seeped by. Could this oil be affecting motor
 

jbuote

Lieutenant Junior Grade
Joined
Aug 17, 2016
Messages
1,001
Completely new to outboards, and may be off my rocker here, but...
​I'd wonder about crankcase compression.. Is the crankcase sealed right? Reed valves closing?
​​If I'm not mistaken, crankcase needs a vacuum to pull from carbs, and then pistons use pressure to get fuel to the cylinders.
​I think if the crankcase is leaking air, it won't let the fuel/oil, ether, or anything make it to the cylinder...
Are plugs wet with fuel when you pull them out after trying to start?

​Compression test shows cylinder compression, but if crankcase is leaking on the "Bottom End" if you will, I think that can mess it up too..

​Again... I'm completely new to outboards and 2 strokes, but thought I'd throw that out there....
​I could be completely wrong, so Please! Feel free to ignore me if I'm way off base.. I'm sure the real pro's here will guide you properly...
​Just a thought, for what it's worth...
 

flyingscott

Fleet Admiral
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Apr 8, 2014
Messages
8,151
What did the flywheel key look like? Did you try putting a fuel mix in the plug holes?
 

OptsyEagle

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Sep 13, 2006
Messages
1,359
I agree. Put a little premix into the plug holes and check for a pop. If no pop, then recheck your spark and I would recheck your timing. Unfortuneately the timing is determined by the point gap. I assume you set them to 0.020" gap. You could use a multimeter to check the timing of the spark as well. I just set a multimeter to continuity. Connect a lead to the point and the other to any ground and slowly turn the cam. The multimeter should stop beeping or go to infinite resistance the millisecond the point opens. Stop turning and take the flywheel top and align it over the flywheel key. Is the straight timing mark in the middle of the other one?

Also, check the link and sync. Probably won't be your problem but it does adjust your timing advance. When you turn the throttle grip, does the arrow on the throttle cam fall in the middle of the carb roller JUST when the cam hits the roller. If it doesn't, then adjust it with the two 5/16" nuts on the cam on the starboard side of the motor. Will need a thin wrench to adjust them if the flywheel has not been removed.

Also make sure your choke is operating properly. I had one held up by some wiring (same motor actually) I stuffed under it. When I pulled out the choke it would make all the same clicks etc., but the choke was only closing half-way and the motor would never start. I even added premix to the carb throat and could not get it to go. I then added seafoam to the cylinders themselves and she fired right up. It took me a while to determine that my choke was not closing completely when the choke puller was fully pulled out.
 

Starboardlean

Seaman
Joined
Feb 15, 2016
Messages
73
Link and synch is off,roller touches came about 3/4 in starboard of mark.Choke is fully functional.Flywheel key was sheared when I purchased. Had to remove lobe to get a piece of the key out.A squirt of premix in the jugs got nothing. Points set with feeler. With the compression as is and premix in the hole nary a pop....I had to have messed something up . Sizzling hot spark+ premix should be a pop.

Could y'all elaborate on what ohm meter use what lines up with what when the point opens??
 

tomhath

Master Chief Petty Officer
Joined
Dec 5, 2007
Messages
814
With the flywheel off, rotate the crankshaft by hand until the top piston is at TDC. Then check if the points for that cylinder are just opening.

Also, from Leroy's Ramblings (
http://www.leeroysramblings.com/johnson_magneto.htm):

"First off for the 9.9/15hp, if you are doing any work under the flywheel, you should consider replacing the original white or black friction ring on the timing plate (actually called the bearing). The new brown ones #322435 are made of Delrin and the word is from a experienced mechanic that this really helps these old motors as they seem to be a tighter fit. John Gill explained the later brown colored one was a tighter fit to make the magneto plate have less slop, especially at idle, so the pull of the flywheel magnets against the coil would not cause the timing to jump around as much and give smoother low speed running."
 
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OptsyEagle

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Sep 13, 2006
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1,359
I would be concerned if the roller was hitting the cam at 3/4" past the mark. That motor has a neutral stop restricting gas flow in neutral. The mark hitting the roller at the right time ensures a little gas is given when starting, but not too much. At 3/4 past the mark, does the cam even push on the roller before the neutral stop restricts it? If so, she will probably never start in that condition. She just won't get enough gas. Adjustment is made by loosening the two 5/16" hex nuts on the cam and moving the throttle cam until your alignment is right. Tighten the nuts back up and you are ready to go.

The above does not explain why you can't get a pop when you put fuel in the cylinders. My multimeter method is not super accurate but probably as accurate as using 0.020 gap. I attach any regular multimeter to the point lead and the ground. Set the multimeter to Ohms. If yours has a continuity tester with a beeping sound it makes it easier since you don't need to stare at the meter when turning the points cam. In any case, turn the cam until the beeping sound stops or the resistance goes from zero to infinite and stop turning. I then simply line up the flywheel by eye on the key and look at the timing marks to see if the single line is between the double line. I should add that after I ensure the timing is correct I have gone back and checked the gap on the points and it has always been 0.020", so OMC's original method of setting the point gap to 0.020" is very accurate or at least accurate enough for what you are doing. Hence I rarely use the multimeter anymore unless I am having some problem.
 

Starboardlean

Seaman
Joined
Feb 15, 2016
Messages
73
It starts and run great with BRAND NEW PLUGS!!!

I always figured cleaned up plugs equaled new plugs. I had the plugs polished up and they performed spark test well. But I guess they failed under compression.

Lesson learned
 
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