Is your dirt bike burning oil and smoking like crazy? Change the top end or cylinder and piston on your dirt bike!! This dirt bike maintenance video shows piston and cylinder replacement on Honda CRF 250 or CRF 450 R dirt bike. Keep your dirt bike running like new with a fresh top end !!
Build at your own risk. I would say this is hard to do and needs a helper. Using a 79cc. Predator engine from “Harbor Freight” a hardware store.
Also a couple of funny things.
The engine seems to be mounted backwards.
The exhaust points right at your legs.
The on/off switch is on the front of the engine away from you.
The pulls start, pulls to the front of the snow blower instead of to the back. (where you are)
The air cleaner is in back away from flying snow, that’s good.
All the controls are on the engine.
Some assembly tips…
Use the engine mounting plate that came with it.
The handle bar can be removed to easier install the new engine. The bottom handle bar bolt, engine side, will hit the engine case. Use a shorter bolt or cut the original one shorter.
The snow thrower drive pulley is two pieces and needs a engine shaft spacer to push them together. Use the one that came off the engine shaft first, to hit the engine drive shaft taper and a 3/4 copper pipe coupling or steel pipe. The copper pipe coupling or better, steel pipe will have to be cut or grind down to approximate length of 1 1/2 inches, to have a exact pulley alignment. Also apply permanent thread lock, the red stuff, to the shaft bolt.
The new engine will mount to the per-made holes in the snow thrower body but a motor brace is needed under the engine and four holes will need to be drilled into the body sides. Angle iron will make the bracket. Also apply permanent thread lock to the four engine mounting bolts when installing the engine.
The wheels have to come off to drill holes in the side of the snow thrower body. Twist off the axle flat star lock washer with pliers and you could reuse them.
Parts you will need…
3/4 copper pipe coupling or steel pipe to be used on the engine shaft as a pulley spacer cut to a exact length.
1 1/2” X 1 1/2” X 3 feet 14 gauge, Plated Steel Slotted Angle Iron
BOLTS TO MOUNT THE ENGINE
5/16”-24 X 3/4” Grade 5 SAE Hex Cap Screws (4)
5/16”-24 Hex Nuts (4)
5/16” Split Lock Washers (4)
BOLTS TO MOUNT THE ANGLE IRON BRACE
AND ENGINE TO BRACE
5/16”-18 X 3/4” Grade 5 USS Hex Cap Screws (8)
5/16”-18 Hex Nuts (8)
5/16” Split Lock Washers (8)