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Omega General Help / Re: Issue with timing belt marks
« on: 18 April 2023, 18:53:31 »For the belts with two sets of marks. The white marks are for engines where the lower idler roller is immediately above the crank pulley. For later engines with the lower roller slightly higher and offset towards the nearside, you would use the yellow marks. Usually the belts have double yellow crank marks and single yellow crank marks for cam sprockets 1 and 2, so for the later engines you would use the yellow marks and the remaining white marks for cams 3 and 4. There shouldn't be yellow marks for cams 3 and 4 on the belt, so it's important to observe the correct rotation when mounting the belt.
Usually the later engines have a lower idler pulley without eccentric adjustment. The earlier engines do have the eccentric adjustment for the lower idler pully. Given that Gates part number XS035453XS is being fitted then it should include a new non-eccentric idler roller and the required screw.
Regardless of the engine type or the backplate and tensioner and idlers that are fitted then all the belts have the same construction, length, tooth pitch and number of teeth. Just that old stock belts might not have any yellow marks.
In any event you don't need the marks on the belt and probably shouldn't rely on them. Rely on the timing gauge.
I decided to fit the belt clockwise, don't know why I started going counter clockwise first time. I used the double white marks for the crank and on one set of cams the yellow marks lined up, and the other the white marks lined up, can't remember what side it was, but got all the marks lining up. i also had to fit the bottom roller on after fitting belt as due to it being a tad tight to fit over the roller. I seen this on the TB video and think I had to do that before as well.
Had to adjust cam bank 1 and 2 with eccentric adjuster to bring it clockwise after doing first rotation, 3 & 4 lined up fine first time. Then done final rotation and everything looked fine using crank lock and cam checker plate.
https://photos.app.goo.gl/Vqfd2PJiQZuZNXyM8