Installation of the Push Rod Guide Plate
This bulletin covers the following Champion Power Equipment models: 118cc Engine (All Generations), 163cc Engine (First Generation), 196cc Engine (First Generation), 208cc Engine (First Generation), 270cc Engine (All Generations), 337cc Engine (All Generations), 389cc Engine (All Generations),, and 439cc Engine (All Generations).
Note: Please read the instructions completely before performing the service.
- Remove the engine cover with the OHV logo stamped on the cover. (4-6mm bolts with 10mm head size) Remove the cover carefully and slide the breather hose away.
- Remove the spark plug at this time and position the piston at its highest point (TDC - Top Dead Center position). At this point, you will notice the intake rocker arm will have free side-to-side movement. Now rotate the engine a little further and you will feel the exhaust rocker arm becoming free to move side-to-side.
- Loosen the lock nuts holding the stud bolts used to retain the rocker arms; first by holding the large nut and turning the 6mm (small) nut counter clockwise to remove. Do the same with both the stud bolts. When the nuts are removed, you can slide the rocker arm off the stud bolt. Both rocker arms are identical so you do not have to worry about confusing them.
- Remove the pushrod upward and out of the engines. (They are small tubes of metal with special sockets at each end.) Now you can also remove the stud bolts holding the Pushrod Guide Plate on. When the last stud is removed (just two of them) you can install the new plates with the same bolts. This time install two of these plates for extra durability. Lock the stud bolts firmly and the plates will hold together.
- Reinstall the pushrods and then the rocker arms over the shafts. Place the large nut on first and the small locknut. We will adjust the nuts after noting that the flat side of the arm is on the valve springs end and the pushrod is fitting in the dimple of the opposite end of the pushrod.
- When adjusting the valves, be sure the engine position has not changed, otherwise go back until the engine is just past the TDC (clockwise direction) where the valves will be fully relaxed with the rocker arm. Tighten the large nut down while retaining a small amount of side-to-side freedom of the rocker arm. Then tighten down the lock nut until both nuts have been tightened against each other. Check for side-to-side freedom of the rocker arm after locking the nuts together to prevent the adjustment from changing. This procedure is the same for both valves and is done at the same position of the piston (TDC). Readjust if necessary to get the right movement.
- Using the recoil assembly, turn the engine slowly. Watch the intake valve go down (open position), then return back to the highest position (closed) of the valve, and continue to the top dead center of the piston. The intake valve rocker arm should move easily side-to-side, but must not have excessive vertical clearance. (Recommended clearance on the intake valve is about .004 of an inch.) After this is confirmed, rotate the engine only about 1/10 of a rotation and confirm that the exhaust valve has a similar feel. (Recommended clearance on the exhaust valve is about .006 of an inch.) Double-check your adjustments and readjust if the side-to-side movement is not happening. (No side-to-side movement indicates that the valve adjustment is too tight.)
- If you feel solid compression at the spark plug hole by placing your finger over the hole and pulling the rope, then you have a good adjustment and the engine should start.
- Now you can replace the OHV cover and secure the breather hose in place inside the cover. Inspect the gasket for any damage and use a light silicone sealer on the sealer area if it has any damaged spots.