7 - 6 Genie S-80 & Genie S-85 Part No. 34032Service Manual - First EditionSection 7 - Repair ProceduresPLATFORM CONTROLS1-2Horsepower Limiter BoardThe horsepower limiter board is responsible forgoverning drive pump output. It senses enginerpm from the alternator. The horsepower limiterboard senses drops in rpm normally due toincreased drive resistance (rough terrain orincline), and decreases voltage to the drivecontroller which in turn decreases voltage to thedrive pump, thereby reducing pump output tomaintain optimum engine rpm and horsepower.Three adjustments are required for optimumperformance.How to Adjust the HorsepowerLimiter BoardThe engine rpm must becorrect before performing thisprocedure. See MaintenanceProcedure B-12, Check andAdjust the Engine RPM.Do not adjust the horsepowerlimiter board unless the staticbattery voltage is above 12V DCand the alternator is operatingproperly with 12.5 to 14.5V DCoutput.Gasoline/LPG models: Performthis procedure in gasoline mode.Boom up/down specificationsThreshold 3.5V DCBoom extend - Max-out 9.75V DCCycle time 140 to 170 secondsBoom retract - Dual (lo) range 8.9V DCCycle time 80 to 110 secondsRamp rate 3 seconds8 Set the dual (lo) range: Press down the footswitch, then move the control handle all theway to the RETRACT position. Adjust the voltageto 8.9V DC. Turn the dual range trimpotadjustment screw clockwise to increase thevoltage or counterclockwise to decreasethe voltage.9 Start the engine and move the engine idlecontrol switch to foot switch activated highidle (rabbit and foot switch symbol). Lowerthe boom to the stowed position.Engine should be at normaloperating temperature.10 Start a timer and record how long it takes forthe boom to fully extend. Adjust themax-out trimpot to achieve an 140 to 170second cycle time.11 Start a timer and record how long it takes forthe boom to fully retract. Adjust the dual rangetrimpot to achieve an 80 to 110 second cycletime.If the function cycle time is notachievable, check the relief valvepressure. See 10-2, ValveAdjustments - Function Manifold.12 Turn the engine off and re-connect thevolt meter.13 Pull out the Emergency Stop button tothe ON position.14 Press down the foot switch and then move thecontrol handle all the way to the EXTENDposition. Record the maximum voltage reading.15 Start the engine.16 Start a timer and simultaneously move thecontrol handle all the way to the EXTENDposition. Note how long it takes to reach themaximum voltage recorded in step 14. This isthe ramp speed.17 Set the ramp rate: turn the trimpot to obtaina 3 second ramp speed. Turn thetrimpot clockwise to increase the time orcounterclockwise to decrease the time.
