Mercury 200 20hp pull start

Joined
Apr 23, 2014
Messages
7
I have just recently purchased a mercury 200 20hp I'm pretty sure it's a 1973 but it's really hard to pull start I was wondering if this is a bad thing? Also is there any way to make it easier to pull start? It hasn't ran in a couple of years maybe after it starts and runs a little bit will it become easier to pull start?

Thanks!!!
 

seanymphmike

Cadet
Joined
Nov 20, 2012
Messages
27
Re: Mercury 200 20hp pull start

I've had a love-hate relationship with one of these motors for a couple of years now. After finding and fixing a loose fuel line under the carburetor I'm back to love. Yours is a '73 by the way. There's a site called old mercs that you might find helpful. Did you ever find a starter? Have you had the motor running? I'm not a big man and mine pull starts without an unusual amount of effort. My mechanic told me that the compression on both cylinders is 130 psi, so you are trying to overcome that. If it sat for a few years the cylinders might have rusted. Have you pulled the plugs and looked in there? Also it should be easier to turn over with the plugs out. Might be worth a try.
 
Joined
Apr 23, 2014
Messages
7
Re: Mercury 200 20hp pull start

I bought the motor about 2 weeks ago and it needed a new switch box so I got one , the guy I bought it from said it ran before the switch box went out which was about 3-4 years ago and it hasn't ran since after I hooked up the switch box it had spark , and it did have a starter which worked for about all of 2-3 seconds , I've looked everywhere for a starter they're just hard to find I did however find one website that said they rebuild these starter models for $200 and yes I've pulled the plugs out and the pistons look fine and it is a lot easier to pull with the plugs out but once the is put the plugs back in its really hard to pull start

Thanks again for the help
 

seanymphmike

Cadet
Joined
Nov 20, 2012
Messages
27
Re: Mercury 200 20hp pull start

Have you looked at the similar threads at the bottom of this page? There are some suggestions there that you might try. I've never tried the seafoam product and 2 cycle oil remedy but it sounds promising.
 
Joined
Apr 23, 2014
Messages
7
Re: Mercury 200 20hp pull start

I tryed the seafoam and it didn't loosen it up to much I'm just hoping after I start it and let it run for a few minutes it will loosen it up a little
 

nickcunn

Petty Officer 2nd Class
Joined
Jun 26, 2007
Messages
109
Re: Mercury 200 20hp pull start

take your plugs out and mix you up a small amount of fuel. say 50:1 or 60:1 ratio of fuel to 2 stroke oil. place in spray bottle and spray the cylinders down with it, turn cylinders over a little bit. then spray more. Then let it set for 2 days. Then start it.
 

CigarXO

Cadet
Joined
Apr 29, 2014
Messages
21
Outboards467137 - did you find a remedy? I bot a 75 Merc 20hp 200 and I'm having the same issue though the seller said it ran just weeks ago. I started with a repair/rebuild to the starter to get it to engage, but now cannot get the pull cord to turn the piston. As with you, much easier with plugs removed.
Any ideas?
 
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