Not good for a 2-cycle to run lean?

[Bearcamp]

How could one tell if a 2-cycle is running too lean. I had another post where a person told me to make sure it's not running too lean. Use a pyrometer. What do they do, how do you use them and where can I get one. He also stated to keep an eye on the plugs. What do I look for. Just wanta make sure cause this motor is really runnin good. I ran it for about an hour (hard) and performed the way it should. This all came about on the other post I had about, 1971 Johnson smokes at idle.

 

[DJ]

Re: Not good for a 2-cycle to run lean?

An exhaust pyrometer measures the temperature of the exhaust. A lean mixture burns hotter, to a point.<br /><br />You can accomplish similar results by monitoring head temperature with an infrared/handheld guage. Available at most tool stores.<br /><br />The head temp should not exceed 145-155 under heavy load. Even that can be tricky. Remember, you have a (raw) water cold cooling system.<br /><br />The spark plugs should be a medium tan color with no signs of hot spots (white). If you see metal transfer, onto the plugs, it's too late-damage done.<br /><br />I would realy set everything to factory spec's. The engineers that designed the engine spent mega$$$millions developing it.<br /><br />As previously stated, a lean mixture is the number one cause of two stroke engine failure.<br /><br />If the idle smoke really bothers you, decarb it and switch to a full synthetic oil. It will help.<br /><br />See decarb procedure here.<br /><br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=36;t=000016

 

[Bearcamp]

Re: Not good for a 2-cycle to run lean?

Ok first of all I'll set the float level to specs. Then I'll take it out and run it hard and check the head temp. I did pull the plugs and they look good. I do still have some smoke, but not much. Doesn't bother me. I had the top adjusting screw (no bottom one, just a threaded plug) at 1 1/2 turns and it would sputter from takeoff, so I had to turn it in to about 1 turn, then it took off good. I'll get an infrared tester and check the heat at the head. I just wanta make sure I'm not runnin too lean. And that top adjusting screw is for idle, right????Bottom one would be for high speed????But I don't have a bottom. So how is that adjusted? Doesn't skip a beat at high speed.

 

[MarkAB]

Re: Not good for a 2-cycle to run lean?

DJ<br />What does the metal transfer look like. I have had a sudden loss of power and on the one plug, although "tan" in color has small round spheres stuck onto the inner side of the plug. Could this be too late for me?