Unable to pull stater rope

S

S10nook

Cadet
Joined
Mar 13, 2021
Messages
8
Was running my mercury 20 hp 2 stroke engine when i suddenly died. tried restarting with no luck. Found i had water in gas line. Drained gas line, rebuilt the carburetor with new gaskets and cleaned it out. . Added new fuel and tried to restart engine. Was unable to pull start the engine. The starter rope will only pull several inches and stopped. Took out the spark plugs and was able to pull the the re fully out. Did a compression test on both cylinders at 100 which was what I had before this incident. Figured there was an issue with compression at this point. I tilted the engine up as far as possible to get it horizontal and put marvel mystery oil in to soak for a day then sea foam to soak for a day followed by a rust penetrating oil. The oil dripped out of the engine overnight. Tried to pull the starter rope with plugs after spraying oil into cylinders and rope still sticks. I am able to rotate the flywheel; i can rotate the fly wheel with the plugs in but still sticks in certain areas but able to go full revolution. Any suggestions at this point.
 
Grub54891

Grub54891

Admiral
Joined
Jun 17, 2012
Messages
6,077
Pull plugs and turn the flywheel by hand. Feel for the binding. It's entirely possible that a magnet came loose under the flywheel, causing the resistance. Or the motor gave up the ghost from the water getting in there. I think you have to figure out how the water got in there also.
 
S

S10nook

Cadet
Joined
Mar 13, 2021
Messages
8
Water was in gas. Thats why i drained fuel line and got new gas. I had thought that about a magnet since it does bind in one area when turning flywheel by hand. How would you be able to tell that without removing flywheel. I am a newbie to outboards. Was able to rebuild carb. Looking at other posts how would i be able to tell if lower unit is causing the flywheel to bind. Prop moves freely. Able to turn flywheel with plugs in but it binds in some areas. Any advice would be great. Sorry for typos.
 
Grub54891

Grub54891

Admiral
Joined
Jun 17, 2012
Messages
6,077
You can remove the lower unit and see if it frees up the motor. You also have to remove the flywheel to see if the magnets are broken. I’d be looking for a factory manual before proceeding any further as you said you don’t know alot about outboards. Possibly check out some u-tube videos about service of your motor.
 
C

cyclops222

Lieutenant
Joined
Mar 21, 2024
Messages
1,307
Your first 3 sentences are very important !
It stopped running.
You tried to restart it.
Would not start.
It pulled NORMALLY right after stopping ? Or it already had the hard pull problem ?
 
C

cyclops222

Lieutenant
Joined
Mar 21, 2024
Messages
1,307
I would do the flyingscott or pull the flywheel.
To me the flywheel would be simpler. And also show up any shaft key damage. Or magnet damages. Good Luck.
If the flywheel magnets check out OK ?
Then Lower Unit damage becomes a possibility.
Only because you feel resistances at different places as you rotate the flywheel. I hope you find a loose ignition magnet or pickup coil.
 
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