I have two Super Tigre G21/46 motors which I recently purchased and have not yet run. I note that both motors are set up so that the skirt of the piston uncovers the exhaust port at TDC. I have never seen this on other motors. Is this unusual? What effect does this have?

Hi Dallas

It is common for The ST 46 to have the piston uncovered in just the bottom outer edges (I have seen this many times), but not the whole bottom of the piston, is it possible this is a ST40?
On the ST 46 the small amount of  sub port induction will not hurt the run, If you have a lot of the piston uncovered you will want to use a muffler that does NOT  have  a lot of back pressure, the less amount the better.

Randy
Randy

Hi Randy,

I got one ST 60 that the piston will do the same, is that also normal for an ST 60 ?


Martin