User manual YS FZ140-2

[. . . ] This concludes the break-in procedure, It is advisable to always use a slightly rich setting to keep the moving parts lubricated, even atter the break-in period . TAPPET CLEARANCE ADJUSTMENT 1. No adjustment is necessary until atter 1 hour of operation (including break-in period). Clearance adjustment should be done when the engine is cool. When the engine temperature is high, clearance is higher due to thermal expansion. [. . . ] Remove the carburetor and backplate assembly. Notice the impression made on the crankshatt counterweight. Position it directly straight down or in line with the case outer seam line. When reinstalling the cam gear, the side with a point mark should be facing the opening of the gear box, Note that it should also be mounted with the point mark located towards the top of the engine just below the cam followers. FEATURES PROPELLER INSTALLATION The FZ140 is a new generation engine that conforms for the new F3A regulations. As in our 120 series, we equipped it wilth a supercharge system assisted by the fuel tank pressurization mechanism. The result is a powerful engine that is lighter in weight than our 120 `s Although the FZ140 has a bigger bore and stroke than our 120 Series, it will fit the same mounting bolt pattern. Due to the high torque of the FZ140 engine, we have equipped It with double locknuts for safety. Mount the propeller and tighten the rear nut. Next, tighten the front nut as shown in Fig. 1. Select a good quality propeller that will turn in the 8, 000 to 9, 500 range, We recommend sizes 14x14, (15x12 through14) (16x10 through 14). LOW SPEED ADJUSTMENT This engine is equipped with a new low speed needle valve to adjust the mixture from low to mid throttle. This needle valve is located on the side of the throttle barrel opposite the throttle arm (Fig. 1) 1. Open the low speed needle valve to 1 1/2 turns from fully closed position. The low speed needle valve should be set after the high speed needle valve has been adjusted. Close the throttle gradually to an idle (approximately 2500rpm). Let it idle for 20 to 30 seconds and then slowly advance the throttle. The adjustment is satisfatory at low speed if transition is smooth at this time. If the engine is runnlng rough on idle, the low speed mixture is rich. If the engine starts to speed up and dies on idle or starts to detonate, when advancing the throttle, the mixture is lean. Turn the low speed needle valve clockwise to richen and counterclocwise for a leaner mixture (note that the direction of the low speed needle valve is opposite the high speed needle valve). Adjustments to the low speed needle valve should be 1/8 to 1/4 of a turn increment at a time to achieve smooth throttle response. DIAPHRAGM AND CHECK VALVE DISASSEMBLY Diaphragm: 1. Remove the adjustment screw of the valve, and then remove the inside valve and spring. Clean the inside with alcohol or appropriate cleaner. Reassemble. [. . . ] Close the throttle to the idle position and connect the glow plug cord. DO NOT ATTEMPT TO START AT FULL THROTTLE, AS THIS IS VERY DANGEROUS. INSTALLATION 1. Connect the engine to the tank as shown in fig. 1. Since high pressure is applied to the tank, tighten all connections carefully. [. . . ]