What is bottom end on a dirt bike?
the bottom end is the bottom half of the motor containing the transmission.
How do you split a dirt bike case without a tool?
If you do not have a crankcase splitting tool, splitting the cases is possible using a commonly available harmonic balancer puller (available at auto parts stores) along with 2 (long) 6mm x ~150mm bolts and a dead blow hammer.
What is a crankshaft on a dirt bike?
The crankshaft has a connecting rod attached to it at each of the four crankpins. Each rod has a piston rising and falling in its respective cylinder. Classic motorcycles of yesteryear had roller- and ball-bearing crankshafts.
Can a crankshaft be rebuilt on a dirt bike?
The crankshaft should either be rebuilt or replaced depending on the severity of wear and desires of the builder. ProX connecting rods are double-forged, Japanese steel, and are heat treated and shot peened for strength and longevity.
What kind of oil do you put in a crank on a Yamaha?
Some units like the middle drive, and the final drive on my XS11 Yamaha use a type of gear oil. The parts inside are like a crown and pinion in the rear end of an auto.
Can you change the oil in a crankcase?
So the crankcase oil supply is never subjected to combustion gases and stays relatively clean and pure. Only time and heat will necessitate changing it. I just picked up a pair of early 70’s 2 stroke bikes.
How do you put a new chain on an engine?
To put the new chain on, tie a piece of tie wire around the chain and poke it up through the cases, allowing you to pull the chain up from the top. This photo shows the new chain before it gets fed into the engine’s cases. 10. Reassemble The Engine
Why do I need to remove the cranks on my bike?
Cranks may be removed to replace cranks or chainrings, service the bottom bracket bearings, or to clean the chainrings. Crank systems have become more complex in recent years. To know the service options you will need to know the type of crank and type of bottom bracket bearing system installed in the bicycle.
How to rebuild bottom end of dirt bike?
A top end rebuild is quite straight forward, but a bottom end rebuild gets a little more complicated. If you can’t find a workshop manual for your dirt bike, take pictures on your phone as you remove each part, and write a list so you can simply reverse the list to reassemble the engine. You’re now ready to remove your dirt bike’s engine.
Do you have to replace both cranks on a BMX bike?
Both cranks must be removed to service or replace the bearings of a three-piece system. Both left and right cranks will have crank bolts in the arms. Three piece cranksets generally have one of two interfaces: square spindle arms or splined spindle arms. Many BMX and freestyle bicycles use a unique crank system that utilizes a 48 spline spindle.
How do you remove a crank from a park tool?
The left side crank is removed to get to the bearings or to remove the right crank. Ultra-Torque™ is a proprietary crankset system used by Campagnolo® and Fulcrum®. With this system, both the left and right crank arms are fitted with one-half of the spindle system, with teeth machined into each spindle end.