DIY: cam setting

[jbthumper]

hey guys!!

can anyone teach me how to set-up those cams for the 125??
from scratch...like....how to loosen the timing chain....
how to check piston position and coordinate with the right cam position??

does the intake cam suppost to feel tighter than the exhaust cam???


i thank all in advance.

p/s:pics or diagrams or both would be great!!

[witttom]

can anyone teach me how to set-up those cams for the 125??
from scratch...like....how to loosen the timing chain....
how to check piston position and coordinate with the right cam position??

p/s:pics or diagrams or both would be great!!

Wouldn't mind seeing this information myself!

[mphcycles]

can anyone teach me how to set-up those cams for the 125??
from scratch...like....how to loosen the timing chain....
how to check piston position and coordinate with the right cam position??

p/s:pics or diagrams or both would be great!!

Wouldn't mind seeing this information myself!

The 6 mm plug screwed in the frt of crankcase is the TDC locator. Use a 5 allen pin, rotate the crank till the pin drops in. Now youre locked at TDC
The cams have a punch mark, intake is at 9 oclock, exh at 3.Flush wtih head parting surface.
I dont have any pics, but its a doddle of a job. If you have ever timed a four stroke , you can do this guy.

[jbthumper]

info is great!!but i'm too scared to do it without a diagram...very much a newbe on engines...

i think i have a rough idea on how to position the cams....but using the TDC locator,that i have a problem with

[jbthumper]

Now youre locked at TDC
The cams have a punch mark, intake is at 9 oclock, exh at 3.Flush wtih head parting surface.

i think i managed to find the TDC...i poped in the 5 allen just like u said...turn the crank shaft until it feels somewhat stuck...where the 5 allen had jammed it on TDC...right???


for the intake and exhaust position....is this viewed from tthe crankcase side or charging coil???

[witttom]

i think i managed to find the TDC...i poped in the 5 allen just like u said...turn the crank shaft until it feels somewhat stuck...where the 5 allen had jammed it on TDC...right???

for the intake and exhaust position....is this viewed from tthe crankcase side or charging coil???

Are you taking pictures while you do this??

[jbthumper]

i still need to know from which angle to view the cams...you know...the 9 and 3 o'clock thing....will be posting those pics once i know....

[bdalameda]

I would make sure that the 5mm locking bolt is ground down on the end so it can engage the crank TDC point properly. The MZ tool is hardened so that it cannot be sheared off if using to lock the engine. You will be looking at the end of the cams from the mag side of the engine. The forward hole in the cam (bottom edge of the hole should be even with the cam cover gasket surface when the cam is timed properly. The cams are held in place by only a friction lock by tightening the cam sprocket center bolts. When you remove these bolts make sure to clean the threads very well both on the bolt and internal cam threads, use contact cleaner or alchohol. Use only blue threadlocking loctite on the cam sprocket bolts when re installing them, never use the red or you will never get the bolts out again. The engine will actually run better if you time the intake cam forward so that the hole in the cam is about 50% covered by the gasket surface. the engine will pull top gear better and have a more even powerband. Make sure you remove the cam chain tensioner if you are removing the cam sprockets. After making the adjustments to the cam timing remove the crank lock bolt and turn the engine over a couple of times and recheck the timing.

[jbthumper]

Roger that. Thanks man!


here are the werx that i did...

fisrt of all i just pop open the head cover...
then...[/img]

[jbthumper]

Then,unscrew the allen plug in front with number6...

[jbthumper]

with pushing the number5 allen in,rotate the magnet(PIC 1) until the number5 drops a bit deeper in the crank...you will feel the restriction on the magnet...this is the TDC position

[jbthumper]

loosen the cam sprocket like so...
(do on both cams if you need to set both)

[jbthumper]

i think you guys can follow fom what bdalameda says on the position...

don't forget to tighten them cams up...

take out the number5 allen and spinnnn the magnet....

[jbthumper]

DONE!!
i thank all of you guys that helped me and those who took their time to see these pictures!!(sounds like something from the Grammy Awards..lol)

[jawzx]

Hey JB, I can't quite tell 'cuz it's out of focus, and a little low resolution, but is that an Alfa Romeo wheel I see in the background?

Nice pictures of the job by the way, very helpfull!