Instructions from two amateurs for replacing derby engine seals. You need a basic socket set, a drill, a magneto puller, a small standard puller and a hammer :)
1. Remove the exhaust pipe, the two bolts at the front and any brackets.
2. Remove the magneto cover and the gear pedal.
3. Remove the front wheel and magnet. In the absence of a bolt gun, we hammered the nut open. NOTE! when removing the magneto out, first tighten the removal tool firmly.
4. NOTE! mark the position of the base plate on the block, this will adjust the ignition! need to put exactly the same place back !! Remove the stator and base plate.
5. Open the oil props, there are 2 in the derby.
6. Open the clamp on the cooling pipe and drain the fluids.
7.Remove the brake and start pedals. Lift off the clutch control lever and loosen the clutch bush bolts. the clutch cheek is often well sealed. Leaves with the help of a knife. NOTE! the starting pedal shaft springs are challenging to put back in place. Depress the starter pedal shaft while pulling the cheek open to prevent it from coming loose from its cavity.
8. The nut of the primary wheel leaves with the same technique that we used in the magnet, we have to hold on to the clutch assembly.
9. Remove the Clutch Plates. as well as the bottom bolt of the setup, leaves by tapping as long as you hold on to one side, or put the stroller back in place.
10. Remove the shift pedal shaft.
11. Remove the primary sprocket. this requires some kind of puller, we used motonet's cheap tool (150mm) it's not the best possible because you have to catch the sprocket teeth, but we've used it a couple of times. Tighten the tool a little at a time and tap with a hammer.
12. Exchange of seals. with a 2mm metal drill bit, drill a hole in the metal ring in the middle of seal. NOTE! be careful not to scratch the shaft or puncture the bearings behind seal with a drill bit. Wipe off metal dust before removing the seal. The holes loosen the seal, tap it a little diagonally and pull it off with a hook, we used an L-key. In addition to the crankshaft steps, you should also replace the gear pedal and front sprocket seals. the transmission pedal seal can pull off with cam pliers. New ones go into place with thumbs pressing.
A few words about assembling ... make sure to return the start pedal when you catch the clutch cheek. both see that the primary sprocket and the magneto crescent wedges are in place.
Hope this helped someone, please leave a comment if any point is unclear.
-Toni
7 сен 2024
