how long till new top end

[killerkx]

i recently had the entire top end of my 97 kx 125 rebuilt, new piston, cylinder, ring, head.... its running better than when i bought it brand new. i was wondering how long befor i should need a new ring/piston/replated?

 

[CaptainObvious]

Longevity of a top end is dependent upon many factors: i.e break-in, maintenance, environment, how it is ridden, jetting - to name a few. Figure a range from 15 hours for a bike with a hard life to 100 hours for a bike that see's light duty and good maintenance.

As far as top speed, that too is dependent on a number of factors, such as sprocket selection (final gear ratio), jetting, rider weight, surface, environmental conditions. Pick a number and defend it...that's what most people do.

 

[killerkx]

i dont really ride that hard... i dont race or anything, just trail ride and cruize around my neighborhood, but i do like to ride wide open!

 

[earl pittz]

I ride about like you do, I change the piston and rings about every 20-25 hrs..

 

[Xtremesports445]

i'd bet they'd last 30-40 hrs. but you'd only have to change out piston and rings, not the entire cylinder

 

[mmz77]

you'd only have to change out piston and rings

Or just the rings, most of the time the piston is fine unless you fail to maintenence it regularly or just plain abuse it :aj:

 

[Moparman1539]

yeah.. im going to start replacing the rings/piston every year. once a year. beause if it blows up.. then you have to replace the cylinder.. which cost alot more money :nod:

 

[2strokerfun]

When you start feeling a loss of power or it consistently takes a few more kicks to start it, it's time to pull it apart and measure piston, cylinder and ring end gap to see if anything is needed.

 

[killerkx]

thanks for all the info, i had to get a new cylinder cause i when i brought it to the shop to get the head torqued back down (i dont have a torque wrench) they over tightened the cylinder bolts and cracked the cylinder.... but its ok cause they payed for the cylinder!

 

[kawicam250]

one of the easiest signs that tell you to replace the top end is lack of compression and lack of low-end. when youre bike becomes weaker off the bottom than normal, that is a good sign. but a more accurate sign is if you have low compression.