Merc thunderbolt needs choke to run

[Got One!]

I have an 87 Merc thunderbolt 200 (20hp) It never seems to warm up (or something) Anyway It requires about 3/4 choke to run. Full choke it dies no choke it dies. If I put the choke in, it will start to die unless I pullit out all the way very fast, then push it in..and out..and so on.

If I get it just right at about 3/4 choke it runs perfect.

Needless to say its driving me nuts. I replaced the fuel line and put a filter in it. The gas is around 6 months old but has seafoam in it.

I'm probably going to replace the tank and fuel although I don't think its the issue.

Anyone know the idle screw settings on this or have any suggestions?

It started this last trip to Odell, but then it ran perfect at 1st start in the AM, I would run out to where I wanted to go, then it would do the choke thing for arouns 15 minutes, after that it would run fine again.....until the next time I shut it down and went to re-start.

Thanks!

[Got One!]

It was bad gas....ugghhh :D

So what I ended up doing was draining the fuel hose, and dropping the line in a gallon of new mixed gas. After a minute of running, it was running like a champ. I'll just replace the old tank and gas with new replacements for both.

Glad that was all it was. That gas being bad makes no sense as it must have been bad from the get go. Live and learn.

[fishkisser]

Glad it was a simple fix ... You might want to try sta-bil marine formula it is designed for ethanol blends ...
http://www.goldeagle.com/sta-bil/stabil_marine.htm

[Got One!]

Glad it was a simple fix ... You might want to try sta-bil marine formula it is designed for ethanol blends ...
http://www.goldeagle.com/sta-bil/stabil_marine.htm

Thanks, I hadnt tried that yet. Ethanol is brutal on steel tanks, and components. My old gas line didn't seem like it was handling it well either. It looked to be breaking down the rubber/nylon lining of the hose.

I bought an ethanol friendly ball and hose.