hi,
I was wondering what are the signs that my piston and rings are shot?
because the other day i was riding my YZ 125 n the rode slow and low RPM`s (because i was pulling my glove on) and then it started not wanting to rev up and sounded weird then it died [img]i/expressions/face-icon-small-blush.gif[/img]. now I can`t get it start for very long time. only a couple of seconds. also sometimes it sounds like a woosh of air is coming out the muffler.
also my dad turned the engine over and thought the piston was clanking.
also were are the reeds on a dirtbike? what would a new pair of reeds do for a bike?

any input would be much appreciated.
-Calum
srry about some words being weird but my comp was eating my words and i could not correct it[img]i/expressions/face-icon-small-sad.gif[/img]

 

pull the plug and see if it is fouled FIRST! The reeds are in the rubber intake that is inbetween the carb and the engine

 

Go to the auto parts store and buy a compression gauge. Then do a compression check.
Rebuilding the top end of a two stroke is very easy as well......

 

Start with the plug advice......that is very easy......make sure the plug is sparking(good).......and isn't fouled. Then if that is all true......do the compression test, as explained. 2 strokes are easy......

 

when it died i took out the plug and cleaned it and it wasa the same.
it was a new plug does that make any difference?
also what will new reeds do?
thnx

 

oops i meant to say i cleaned it and the engine still was the same

 

Well most likely if it was a new plug, you can rule out the plug going bad......but I'd still check to make sure you have spark(or atleast electrical to the plug)........Next, was the plug fouled bad(was it black and oily)?? If so, replace it. If you have done all of this, and it all checks out.......go and do the compression test.......that will tell what is going on internally........You just screw it into your plug hole.......

 

my dad did a compresion test and it was 90 PSI.
thats really low right?

 

yep...............

 

yeah.....if my memory serves me, it should be around 130psi........but don't quote me. Probably time for a new set of rings, and possibly a piston. It never hurts to upgrade the piston to one better than the stocker......now is the time to do it.