1974 Mercury 200 20 hp motor vapor locking

[Cojack7777]

I'm having trouble with a new to me motor. When first trying to pull the pull cord it was almost like the motor was locked up. After pulling the pull housing off and checking it out which had a old pice of rope stuck in it I also pulled both spark plugs and cleaned them. The motor then pulled easier and seemed tobe fine. After making sure that we had spark we found out we was not getting fuel. The carb was pulled off and cleaned with the motor covered and put up for the night in a locked shed. I say all this because the next day after putting the carb back on the motor and trying to pull it the pull rope would not move at all. Think that we had missed a section of rope still stuck in the housing it was pulled back off with nothing found. After reinstalling the pull cord once again we pulled the spark plugs out to see if we had missed anything from the day before with nothing found. After putting the plugs back in the motor turned over very easy and it started three times but was shut off due to not having muffs. After taking a two hour or so break when back outside and the motor started right up. The next day after finding my muffs went and tried to start the motor while hooked up to water and the same thing the pull rope will not move again! Im at a lost with this and any and all help would be greatly appreciated. Am I going crazy or has this happened to anyone else?

 

[racerone]

Local atmospheric conditions were not posted !-------Any water or ice in the lower unit.----Not sure why you are referring to " vapour lock " in this situation.

 

[Cojack7777]

I'm in South Carolina and no ice now. I'm saying vapor lock because of when I remove the spark plugs and there is no compression it will pull fine and when I put the plugs in after that it still pulls fine only after setting for a day is when it seems to build prusser and will not pull. I Called it vapor locked do to the action of what's going one but I'm also lost so I my not have a clue what's it's called lol

 

[Cojack7777]

How can I tell if there is water in the lower unit?

 

[enginepower]

Since it started fine without muffs then was really hard to pull with the muffs on, water may be entering the cylinders. Water can't be compressed and can make it seem like the motor is locked up. You should be able to remove plugs again and inspect for signs of water on plug or in cylinder. If so, you have major problems and should hope it's only a gasket causing it.

 

[Cojack7777]

It didn't have water turned on with the muff when trying to pull we was getting ready to put water to it but the rope wouldn't move.

 

[Chinewalker]

If it was liquid locked and you pulled the motor over with the plugs out, you'd get a gush of whichever liquid was causing the lock, be it cooling water or fuel. Plus, your plugs would be absolutely fouled with either, too.

Are you sure the recoil is not jamming up? When it locks, can you turn the flywheel by hand, without using the recoil?

 

[Cojack7777]

You can use a bar on the fly wheel and it will turn

 

[Chinewalker]

Shouldn't need a bar - you should be able to turn flywheel by hand, even under compression. If you need leverage of a bar to turn it, something is very wrong inside.

 

[Cojack7777]

I will try todo it by hand this afternoon and post back my finding. Thank you for your help