These engines use hydraulic lash adjusters for the intake and exhaust valves,
which require no routine adjustment. However, these engines also incorporate
a 3rd valve per cylinder called the jet valve which should be periodically checked
and adjusted.
- Run the engine to normal operating temperature. Then, shut it off.
- Remove the valve cover.
| Fig. 1: Jet valve adjustment
|
- Rotate the engine by hand until the No.1 cylinder is at TDC compression.
Both the intake and exhaust valves will feel loose and the timing mark for
0 will be aligned with the pointer.
- Check the jet valve clearance with a flat feeler gauge. Clearance for all
engines should be 0.010 inch (0.25mm). If not, loosen the locknut on the rocker
arm and turn the adjusting screw until a slight drag is felt on the feeler
gauge. The jet valve spring is relatively weak, so don't press down on the
valve stem or you'll get an erroneous reading.
- Turn the engine by hand, in the normal direction of rotation, until each
cylinder in the firing order reaches TDC of its compression stroke and adjust
each jet valve in turn.
- Install the valve cover.
No routine adjustment is necessary or possible.
