wr426 02 TDC help

2 replies to this topic
  • Russ

Posted August 06, 2010 - 07:44 PM



I need help trying to understand TDC. I removed the cams and did the shims recently and then lined up TDC with the crank marks and put the cams back in. I turned the crank over by hand to make sure nothing was fouling and saw that the crank TDC mark came around again with the CAMS at 180 degrees? ***?

I assumed that the TDC mark would only line up when the piston is at the top of the compression stroke so i need to find out how you get to this or if it makes a difference if you put the cams in on the exhaust stroke so long as the cams are installed with the crank marks lined up.

Thank you for any help, this is doing my head in :banana:


Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • William1

Posted August 06, 2010 - 09:44 PM


The crank rotates twice for every cam rotation. 2 to 1 ratio

When the cams are out, TDC is TDC. It is only when the cams are installed, then there are two TDC's, one on the compression stroke and one on the exhaust stroke. Just like there are two BDC's, one on the intake stroke, one on the power stroke


  • Russ

Posted August 06, 2010 - 09:51 PM


Thanks mate, that make sense.



Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.