top end rebuild time

[00_yamaha_man_125]

i bought a 00 yz 125 and it has never been blown up or rebuilt. that being said how hard is it to do a top end rebuild? all suggestions will be helpful.



stephen

[mbogosia]

I am in the middle of this right now on my 99. I am waiting on my piston to arrive. Buy a wiseco piston and ring kit at www.rockymountainatv.com . It is only $59.95. They also have a gasket kit for $14.99 . Pick 2 day shipping it is almost the same as regular shipping. Here are some instructions that someone emailed me.

1. drain your coolant. There is a bolt at the bottom of the water pump on the right side that will let all the coolant out.

2. Take off the radiator shrouds and gas tank.

2a. take the exhaust off


3. Take off the radiators.

4. remove the spark plug

5. take the carb and intake off.

6. take the cover off the side of the power valve. should be 4 bolts with a rubber gasket at the bottom of the cover.

7. take the bolt out of the power valve rod

8. unbolt and take the head off

9. unbolt the cylinder and remove.

10. you may want to cover the rod now with a towel so nothing drops in the motor.

11. take the circlip off the piston and remove the wrist pin. sometimes it is a little tough.

12. pop the piston off and replace.

This will get you close I am trying to remember from memory but I think this will work for you. Don't forget to buy a top end gasket kit and replace all the gaskets too.

[BlueDiablo]

and to check the rod bearing....

[bazzwa]

make sure you torque it all down as well dont lose the little sleeves which go over 2 of the cylinder studs that keep it striaght when you put the cylinder back on its all fairly striaght forward just remember how you pull it apart

[kxrider]

theres a trick to taking off tha c clips for tha pistion i have found that using a small finishing nail once u get it started coming out puur hand aound it soo it dont drop in ur engine or shoot out i keep those c clips even thought tha wiseco pistion kit comes with sum new ones cause jus incase u lose ur new one u have sum spares