I've seen people talking about jetting and big bore kits. jetting is for the carb and what does that do? big bore kits obviously increase the engine size? does it just bore out the hole in the engine for a bigger piston?

 

Basically yes.

Rob

 

Usually a big bore kits involves getting a new cylinder with matching piston, rings ect.

 

and jetting the carb does what?

 

Motorcycles come jetted very lean from the factory. This is usually done to meet EPA standards and to a lesser extent MPG. This also is due to the restrictive nature of the exhaust and intake (filters)

When you rejet you add more fuel into the system, therefore increasing power. If you change the exhaust to a performance exhaust, you are adding more air into the mix. With the bike already running lean, this would be a problem. By rejetting, you will add more fuel into the mix.
With most new bikes, they come with Fuel injection which have no jets. You would reprogram the computer for a similar effect.

Clear as mud eh?

 

thanks zbike. that is clear as mud

 

And remember, bro... there's no such thing as stupid questions... only stupid people asking questions!

J/K

 

Jetting + Pipe + the right gears = a whole lot more fun than stock.

 

Fuel is delivered from the gas tank to a "bowl" on the carb. The "bowl" is a storage facility that part of the carb which hold fuel. In the bowl is a "float" The float like a bobber. It is set to "float" at a certain level which helps meter the amount of fuel the carb will allow to pass to the "jets" Jets are copper or simular metal pieces that in the path of fuel flow. They all have a specifically sized oriface which is what allows that amount of pre-measured fuel into the "venturi" which is where the fuel is "atomized" and passed to the engine.

A jet with a larger size allows more fuel into the engine. Engines spin faster and make more hp's with more fuel. The more fuel you add to the engine is said to be making the fuel mixture "more rich". Less fuel going into the engine is said to be making the mixture "more lean". There is an ideal mixture of fuel to air and it is called stochiometric ration. It says that an engine will run at optimal efficiency if the fuel ration is 14.1:1. Anything more and your wasting gas. You could either "fowl" out the plug(make it so wet with fuel that the spark plug no longer creates a spark). You could also end up putting gas into your crankcase is your mixture is to rich which could cause other issues. Depening on how much less your mixture is than that and ou could be saving gas at the sacrifice of performance or you could damge your engine.

Hope that helps.

 

^ show off! ha-ha-ha