Bolens Diablo Care

 

Starting:

500 & 502 – Short pulls of the recoil: Hirth cable recoils do not have a dead end clip on the end of the cable within the rewind. Continuous hard pulls to the end of the cable length could pull the cable out of the rewind. Short pulls are best.

Verify fuel to carburetor:  Verify fuel is being pulled up the hose when starting. If fuel is not being pulled up the hose, disconnect the fuel line from the carburetor and blow a shot of compressed air into the plastic nipple inlet on the carb to “pop” the needle off the seat within the carburetor. This often happens after a motor sits for the summer.

Cold Starts: When starting, apply a full choke and full throttle until the engine fires (typically 4 to 6 pulls for 500 & 502). Then push the choke in and with a full throttle, turn the engine over till it starts. A shot of Carburetor Cleaner down the throat of the carburetor will help get a cold engine fired up.

Fouled Plugs: Champion D14 plugs work best, but all plugs foul at times. If the unit does not start, don’t hesitate to put replace the plug.

Operation:

Fuel Mixture: Recommended Mix is 2-cycle Air Cooled Snowmobile Oil (not injector oil) with Premium Gasoline without Ethanol. Mix at 24:1.

Tillotson Carburetors are finicky: The fuel mix to your engine will change dependent on temperature, barometric pressure and altitude, and usually affects the top end performance. Typical adjustment of the Low Speed Jet is out 3/4 turn. Typical adjustment of the High Speed Jet is out 1 turn.

Adjust the Low Speed Jet and Idle Screw to get the engine to run smooth at a low idle to where the Primary Clutch is not trying to engage. Operate at top speed to know if the High Speed Jet needs adjustment. Tweak the High Speed Jet in or out 1/8 turns or less to get the engine to run at the best top speed of about 30 MPH. You may also have to tweak the Low Speed Jet to get the motor to rev up properly.

Maintenance:

Track Adjustment: Tracks that are too tight will damage sprockets. Adjust the tracks so that they do not slap on the bottom of the chassis when driving. Always adjust the track tensioners equally on each side to ensure the gearbox is straight in the chassis. This is done by measuring the exposed adjustment bolts on each side and making them equal.

Spark Plug – Champion D-14 spark plugs – gap between 0.016” & 0.020”.

Gearbox Lubrication:  Install a drain plug in the bottom of the gearcase and change the oil annually. Only put 4 to 6 ounces of 90w oil in the gearcase.

Bogie Stations: Install lubrication ports and lubricate with oil.

Recoil (if equipped): Once or twice a year, remove the recoil and spray some lubricant into the spring area. A product called “Fluid Film” works great. There is no need to disassemble the recoil to do this.