My Merkur left me on the side of the road a while back, but it was likely the timing belt tensioner not creating enough tension on the timing belt which allowed the belt to slip. Given I needed to adjust the timing belt, I went in search of how to do it. Turns out while you do need to pay attention to how things are lining up, the process isn't that complicated.
- The pointer on the camshaft gear needs to point between the center of the cam bolt to the center of the auxiliary (distributor) shaft gear.
- The crank has its own timing pointer, which goes from center of the crank to the center of the auxshaft. This sets the #1 piston to top dead center (TDC). As I understand, you can also, gently, put something in the #1 spark plug hole to determine if #1 is TDC by rotating the crank until you have the minimum amount of screwdriver inserted.
- Next is the auxshaft. The easiest way to set the auxshaft, which drives the oil pump and distributor gear and therefore the rotor is to just rotate the auxshaft which turns the rotor and get it as close as you can to the right position for plug #1.
- Next is to put the timing belt on, maintaining full tension while working your way counterclockwise from the crank gear.
- First, put the belt on the crank gear.
- Next, pull it tight around the auxshaft.
- Third, remembering to maintain tension, pull it around the cam gear. ***You don't want any slack on the drivers side of the engine.***
- Now you can release the tensioner by loosening one or both bolts that have been holding it in place away from the timing belt.
- Slowly rotate the engine 2 revolutions by turning the crank to allow the tensioner to take up and remaining slack. This is one of the leading causes of belts slipping on these engines. Don't be like me and make sure you do this.
- Check the timing marks, one last time, making sure they're all lined up the way they should be and then torque down both of the belt tensioner bolts.
