Jump to content
Sign in to follow this  

yzf 250 valve timing

Recommended Posts

Hi folks just shimmed my 09 yzf,any tip on setting the valve timing up.

The TDC mark on the flywheel is hard to see,but I can find TDC.

I `am only using the handbook and its a bit vague.

So any useful tip`s appreciated.

Thanks.

Share this post


Link to post
Share on other sites

The bike should be TDC on the compression stroke to shim it anyways but not necessarily. Easier but not necessary. You should see some punch marks on the cam sprockets. With the flywheel "I" mark lined up (not the I--I) the dots on the cam sprockets should all be lined up with the top of the head and the lobes pointing at about the 10 o'clock and 2 o'clock positions

Share this post


Link to post
Share on other sites

You can also remove the plug and stick a pencil down onto the piston to feel for TDC. Just make sure it's TDC on the compression stroke ( cams not touching valves).

Share this post


Link to post
Share on other sites

I'm in the same situation but also changing from WR to YZ cam so I had to change the timing from 13 links to 12 links between sprockets. I think I got it right as I marked the links with chalk but now I am doubting myself and want to double check. All I see is the H mark on the crank. Where is the I in relation to the H mark?

Share this post


Link to post
Share on other sites

The I is right beside the H so essentially it says 'HI' on your crank as it passes the sight window.

Share this post


Link to post
Share on other sites

Thanks for the info.

The I is right beside the H so essentially it says 'HI' on your crank as it passes the sight window.

I found my I as stated it next to the H but its very faint,is there a set amont of pins/links you count between cam sprocket marks?

Share this post


Link to post
Share on other sites
Thanks for the info.

I found my I as stated it next to the H but its very faint,is there a set amont of pins/links you count between cam sprocket marks?

You'll see punch marks on the sprocket. There will be 12 pins between punch marks for YZ timing and 13 for WR timing. If you have an 03+ WR you'll have to file or grind 1mm off the decomp stub before going to YZ timing or the electric start will have a hard time turning the engine over

Share this post


Link to post
Share on other sites
You'll see punch marks on the sprocket. There will be 12 pins between punch marks for YZ timing and 13 for WR timing. If you have an 03+ WR you'll have to file or grind 1mm off the decomp stub before going to YZ timing or the electric start will have a hard time turning the engine over

Okay i was confused it is pins. i was counting links

Edited by SmokinRZ

Share this post


Link to post
Share on other sites

Count 12 pins between the dots on the sprockets.. Also get a whiteout pen and mark the I on the mag with the pen and the top dot on the cam sprockets too.

Share this post


Link to post
Share on other sites

For background info, the I-I marks pass the alignment window mark before the TDC I mark does. This is because the ignition timing, when checked with a timing light, the case alignment mark at the window will line up somewhere between the I-I marks when the timing light flashes, with the engine running at idle speed. Since the ignition spark occurs just before TDC, the ignition timing/spark window I-I marks lead the TDC I mark following in order of alignment with the fixed case mark.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×