dirtnap007

Member
Apr 19, 2009
21
0
I have a 2001 Yz125 and I am currently doing a top and bottom rebuild. I almost have it together but I cannot figure out how to get the timing set. I put the piston at top dead center and put the flywheel back on but it still didn't line up with the positioning mark on the stator and flywheel. Does this mean I have the timing wrong somewhere else in the engine or what? :bang: :whoa:
 

helio lucas

~SPONSOR~
Jun 20, 2007
1,020
0
i can´t remember the 2001 yz 125 yamaha but most line up not on tdc but when the ignition fires. that way you can measure how many degrees, or mm, it fires before tdc.
the service manual shows the proper procedure for checking the timing, as many bikes you need the running the engine at certain rpm and then check the marks with a strobe gun..
 
Last edited:

dirtnap007

Member
Apr 19, 2009
21
0
the manual says to match it with the timing marks on the stator and on the flywheel while its at top dead center. but there is no way to make that happen.
 

helio lucas

~SPONSOR~
Jun 20, 2007
1,020
0
match the marks on stator and rotor? is a internal rotor??? i recall that bike to use a external rotor almost for sure...
 

whenfoxforks-ruled

Old MX Racer
~SPONSOR~
Oct 19, 2006
8,129
2
Merrillville,Indiana
Your stator plate is moveable? There should be 1 index mark to line up, some you need to remove the 1 screw to view alignment. After that, a timing light or read the plug?
 

dirtnap007

Member
Apr 19, 2009
21
0
I will post pictures in a moment of what it looks like, i tried moving the plate but it still will not line up at top dead center. You shouldnt need a timing light to do this procedure, it should be automatically set when you align the timing marks. :bang:
 

Uchytil

LIFETIME SPONSOR
Jun 29, 2003
814
9
I'm sure you intalled the woodruff key and it's flat surface was engaged with the rotor? If so, and the piston is a TDC, the marks should be close but not aligned. The actual timing is somewhere around 0.52mm BTDC (but don't quote me - use the shop manual you have). After you set the actual timing with a dial guage you loosen the stator screws and then align the mark on the stator and the mark on the rotor by moving the stator.

Statr over and see what happens. If it were me I'd stick the piston and cylinder on and use a dial guage (after checking the woodruff key).
 

dirtnap007

Member
Apr 19, 2009
21
0
Well, I just looked at my buddies Yz125 and his timing looks exactly the same as mine. I think I may have just pulled a blonde move and followed the manual to literal. So I think im going to put it back together and if it runs crappy, well then i will know my problem.
 

Top Bottom