Ooops, its clunking again.

[pittspilot]

I have a 1973 Mercury 20 Horse Motor, with compression of 107 in each cylinder, and spark, that I just rebuilt the carb on. My problem is that the motor will not idle for an extended period of time after a cold start, and will not at all when hot. The idle is always terminated abuptly by a clunk. the motor will start again if it is still cold, but if I run it for a while (It occasionally loses power), it will not start until it is cool again. <br /><br />Any clues? I do have a clymers manual.<br /><br />P.S. The motor is fairly hard starting requiring multiple pulls with the choke. It will then fire and die. I will then open the choke, and the engine will idle until the clunk.

 

[Hooty]

Re: Ooops, its clunking again.

I can't be sure but it sounds lean, like maybe an air leak in the fuel line, etc. When it dies, pull the plugs and see if they're wet or dry. I figger they're dry. Could be carb adj. also.<br /><br />Is that "pitts" a Pitts Special?<br /><br />c/6<br /><br />Hooty

 

[pittspilot]

Re: Ooops, its clunking again.

Thx....Yep, in a former life, I was an aerobatic instructor teaching folks in a Pitts bipe. At the moment, I am in school, so no funds for flying. But I will own an S1-11B one day.