Briggs 5 hp running to rich?

[johnf.357]

I just tore down a 5 hp flat head, did the valves and decarbon the piston,completly cleaned inside of the engine,reassemble,I have the set screw allmost all the way in (leanest) but the new292 spark plug still comes out black,after only a few minutes run time!It runs fine,just want it to run cleaner.I do have a k&n filter and an open pipe exhaust on it,and removed the gov..
don't suppose there is anything else is can do to lean it more is there?

thanx

 

[5 Horse Fan]

Well, the way they designed the combustion chamber, the fuel mixture passes the spark plug and ignites right in front of it.

Running an engine too lean is what causes most engine damage.
I would be happy it runs and maybe think about a higher octane fuel or a better designed Carburetor like say a Tilly.:thumbsup:

 

[johnf.357]

rich carb

Well, the way they designed the combustion chamber, the fuel mixture passes the spark plug and ignites right in front of it.

Running an engine too lean is what causes most engine damage.
I would be happy it runs and maybe think about a higher octane fuel or a better designed Carburetor like say a Tilly.:thumbsup:

na,the tilly's to complicated for me,I will be happy it runs,as u put it,leave it as is,and just be happy with that..and move on to the clone build up project next..

thank you, 5 horse