Propane Enrichment Procedure
- Start engine and warm up to normal operating temperature (cooling fan on). Disconnect and plug vacuum hose from intake air control diaphragm. Connect tachometer and check idle speed with all electrical accessories off.
- If necessary, adjust idle speed with throttle screw. Pull air cleaner intake tube from air duct near radiator. Insert propane hose 4 inches into air intake tube.
- With engine idling, depress push button on top of propane device. Slowly open propane control valve. If engine speed increases to enriched RPM, proceed to step 11).IDLE SPEED & ENRICHED RPM INCREASE
Application Idle RPM Enriched RPM Increase Man. Trans. 750-850 75-125 Auto. Trans. 700-800 10-50 - If engine speed does not increase to enriched RPM, remove air cleaner. Disconnect vacuum hose to fast idle unloader. Remove bolts holding throttle opener bracket to rear edge of carburetor.
- On Prelude, disconnect all vacuum hoses and lines from carburetors. Disconnect throttle cable and vacuum hose from throttle opener diaphragm. Disconnect automatic choke lead. Drain coolant and disconnect hoses. Remove carburetors.
- Place a drill stop on a 4 mm drill bit (5/32" from end). Drill through center of mixture screw hole plug. Tap the hole with a 5 mm tap and blow out metal chips. Make a plug puller using a 5 mm bolt, 1/4" drive socket and flat washer. Turn the nut to remove plug. See Fig 1 . Reinstall carburetors in reverse order of removal and replace coolant.
- On all models, reinstall propane enrichment kit and recheck maximum propane enriched RPM. If enriched RPM is low, lean out mixture. If high, enrich mixture. Turn mixture screw clockwise to increase RPM; counterclockwise to lower RPM.
- Run engine at 2500 RPM for 10 seconds to stabilize mixture. Close propane control valve and recheck idle speed. Repeat procedure until idle RPM and enriched RPM are correct. Remove propane enrichment kit. Reconnect air cleaner intake tube.