Joyner JNSZ800DL Owner's Manual page 89

f. Checking and adjusting of valve mechanism
1. Check the mounting position of timing belt
Remove the front shell of timing belt and rotate crankshaft clockwise in order to align the key
slot center (mark1)and round dot " . " (mark 4) on the sheave of camshaft with "↑" （mark 5 ）
on the rear shell assembly. At this time ,the key slot center (mark 3) and round dot " . " (mark
6) on the timing sheave of camshaft should be matched with "↓" （mark 7） on the rear shell
assembly, as shown in Fig .49 . or otherwise, you should adjust it until it is aligned. At this time,
the first piston (close to fan )should be in the upper dead point of compression stroke, i.e.
there should be a clearance between admission exhaust valve and rocker adjusting screw.
2 . Change of timing belt
The timing belt with excessive wear, aliquation and off-teeth should be changed.
When changing it, loose the rocker nut and make adjust screw back to position where camshaft
can turn in order to avoid the valve impacting the piston .Then lose the two fastening belts of
tensioner and remove the belt. When mounting it, you should adjust the positions of the two timing
sheaves according to Fig .49 and confirm the alignment of 2,1,4,5,7, 6 and 3. the mark should be on
a straight line. When there is no loosing on the position "8" of diagram, mount it keeping the arrow
mark on the back of timing belt in the direction of running clockwise and make it tighten by
depending on the acting force of tensioner spring, and confirm the assembly position whether if has
met requirements in Fig .49 by turning the crankshaft clockwise by two rounds. then screw the
Fig .48
Fig .49
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