TESTING ENGINEAAIR FILTER BLOCKAGE INDICATOR
To test the air cleaner blockage indicator (Figure 28) run the engine at full speed for a short time. If the rubber bellows is pulled inwards (down), and the green rubber band cannot be seen, this implies that maintenance work is required on the air cleaner. Clean or replace air cleaner.
Figure 28. Air Filter Blockage Indicator
MDR-9D — MAINTENANCE
AIR FILTER
CANNISTER
CLEAN USING
COMPRESSED
DRY AIR 
AIR FILTER
CARTRIDGE
WING NUT
Figure 29. Air Filter
CHECKINGTHE CHAINS
1.Take off the checking cover on roller and coat grease on the chain if necessary (Figure 30).The chain should be lightly lubricated with motor oil.
CLEANING OR CHANGING ENGINE AIR FILTER
If engine is operating in very dusty and dry grass conditions. A clogged air filter will result in high fuel consumption, loss of power and excessive carbon buildup in the combustion chamber. Clean air filter daily. Remember if operating in dusty conditions, check the rubber bellows on the air blockage indicator several times a day.
CAUTION :
Figure 30. Chain Cover
DO NOT blow high pressure, high velocity compressed air thru the air filter cartridge.The high velocity air will damage the filter, which will then allow contaminates to pass into the engine.
To clean or replace air filter loosen the wing nut on the air filter housing (Figure 29), remove the cover and take out air filter cartridge. If only cleaning of the air filter is desired blow through the air filter cartridge from the inside, moving a jet of dry compressed air up and down until all dust is removed.
2.Check the chain tension and if loose, adjust the chain tension with the tightener (Figure 31). Chain tension should be adjusted every 50 hours of operation.
Figure 31. Chain Tightener
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