Stock cylinder 250r

[punker69q]

I'm looking to buy my first 250r and I want to build it for mx. I'm still in school, so I don't want to spend too much on this bike. I already got a good idea on what I want to do to the suspension, but I have no clue on what to do to the motor. The only thing that I know is that I want to keep the stock cylinder, to keep the cost down.

My question is : can some of you suggest me some affordable engine kits, that would have a decent powerband. I'd like to spend about 1k max on engine work, and I can work on my engine myself, except for porting that I would leave to someone who knows his stuff.

[wilkin250r]

It's not absolutely set in stone, but as a general rule, the more money you spend in your motor, the more power you'll get out of it. $1k can get you decent power, but it's not going to be as fast as some others out there.

The REALLY big variable is the condition of your motor. It's possible to spend a lot of money just replacing the stock compontents for strength and reliability, without any real improvement in power. Replacing the crank alone can cost several hundred. But if you plan in increasing the power output of the motor, and putting it through the rigors of racing, these things are important and should not be overlooked.

As for specific recomendations on engine kits, I don't have any for you, which isn't exactly what you're looking for. Instead, I'll suggest that you do research on different upgrades. You don't need to know exact details, but you should learn the basics of what porting does, and how it will affect your compression and powerband. How does your pipe affect your powerband? What is the squish band? What are the pros/cons of a larger carb vs a smaller carb? Are there any situations in which a smaller carb is preffered? How are aftermarket reeds better than stock reeds?

It's very possible to have a fast motor without knowing these types of things, but it's generally also very expensive. Basically, you throw a bunch of money at somebody else to build you a fast quad, you are paying them for their knowledge and expertise. But if you've got limited funds to work with, and you still want a fast quad, then YOU will have to supply the knowledge. The more you know, the cheaper it gets.

[baker250r]

send your cylinder to RB Racing in Michigan, he does real good port work. It costs 120 for the portwork, 25 i think for decking cylinder. get a cylinder spacer plate and run a 86 style piston. Get a Paul Turner or Lrd Pipe. and a boysen reed valve, that should keep you well under 1000. His email is rbracing@msn.com

[zedicus00]

http://ericgorr.com/index.html this dude can port it for whatever powerband u want and stomp in a 300 kit for like 400$ or less. use the rest of the money for reeds pipe and new carb. u will be smokin ***** then. i would get the low to mid porting. get boysen reeds an a 38 A/S carb. and a esr trx-5 or trx-6 pipe.