Mercury 20hp ran great now won't start

[Jdm802]

I have a 60s model Mercury 200 20hp with lightning ignition, I cleaned it up and had it starting on first pull everytime, then I took it out and ran it on the river for an hour or two but when I shut it off it took about 30 minutes of pulling on it to get it to start again and it wouldn't idle. I played with it a few months ago and got it to start once but it only ran roughly for a minute until it stalled and now it won't start at all. Need all the help I can get

 

[seanymphmike]

I have a '73 model 200. I had similar problems with mine and I can share what I learned through a lot of trouble shooting and head scratching. I now have it running better that it probably has run in many years. My problems all revolved around the carburetor and fuel lines. I suspect yours (like mine) had been idle for some time. I'm not sure if we both have the same carburetor. What is your serial number? That will help identify that.