Adjusting mixture

[Tdarms]

I've been working on fixing up a '81 9.8 mercury. I've got it to the point that it will run for a little while but then it dies on me. During the time that it runs, I've noticed that it runs better with the throttle opened up a little bit. I figure that it is a mixture problem but the problem is that it normally doesn't fun long enough for me to try to adjust the mixture screw on the carb (starting with the scew 1 1/4 out). And to make it more difficult, after two/three runs, it won't even kick at all until the next day. I've tried pulling the plugs to help it air out but that does not seem to help.

Any ideas on how to quickly adjust the screw would be awesome.

 

[ENSIGN]

Re: Adjusting mixture

The first thing to do is check the compression! If it's low it will never run right.Next inspect the fuel and fuel system starting at the tank and lines.Have you rebuilt the carb? 1 1/4 turns out is about the right setting.If you do remove the carb check the reed valves for cracks and holes.

 

[Tdarms]

Re: Adjusting mixture

After some trial and error, I got it to run well for over 30 min. (with screw set at 2 3/4 out!). Though it ran great for me in the bucket, even at high RPMs, it did have much power when I took it out on the water today. If I opened up the throttle more then 1/3 it would die on me. Found that if I gave it a little choke it gave me a little bit more, but not much.

(Yes, the carb was rebuilt. I replaced the float valve, I'll see if I can take a look at the reed valves.)

I'll create a new post if I can't find an old post on this issue.

Thanks for the advice.