cracking exhaust valves

[dumb person]

i found some 2 strokes would not run without an exhaust while others would. Also heard that without an exhaust or backpressure that the piston rings would break eventually, maybe from having no downward pressure on the exhaust side while still having pressure on the other side caused them to shift in the piston lands? A motorbike mechanic told me it would break them but i never tried it myself.

 

[Patrick L.]

You want to break rings on a 2 stroke ?? On my first go-kart [11yrs] I put on a little 580 West Bend 3 port motor.. To make it better I read about squaring and raising the ports.. I worked.. So, by my thinking at such a young age, to make it even better I removed all the material between the ports turning it into a one port engine.. It ran great !,, for about 100 feet.. Those rings came out in about 100 pieces..

 

[MrTube]

To me a two stroke needs an exhaust, specifically an expansion chamber. Its like supercharging an engine. Of course it needs to be tuned to your needs.

 

[Tom Wesenberg]

You want to break rings on a 2 stroke ?? On my first go-kart [11yrs] I put on a little 580 West Bend 3 port motor.. To make it better I read about squaring and raising the ports.. I worked.. So, by my thinking at such a young age, to make it even better I removed all the material between the ports turning it into a one port engine.. It ran great !,, for about 100 feet.. Those rings came out in about 100 pieces..

LOL, I did exactly the same thing to a Power Products engine that I souped up when I was 15. The ring caught on the port lip as soon as I ported it to one large port, so I ground a bevel in the top lip of the port. It worked OK, but I sold it right away as I had no cart to put it on.