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KTM 250+ Big Bore Kit


KTM 250+ Big Bore Kit As 4-stroke motors become smaller and technology improves performance. More power is being developed out of the same size 250 that 5 years ago delivered 33/34hp the same motors today are generating 38/39hp More power means more heat which in effect means the cooling requirements are increasing at the same time. The factories are pushing the limits of the stock cooling systems most modern 250's are sized with no extra capacity and in some cases if you compare part numbers they are still using the same size radiators they used 5 years ago!! The same is true for the bigger bikes as well.

Through our unique sleeve design, Cool Flow (patent pending), we design our sleeves to net a 15-40% increase in surface area (depending on the application compared to a standard sleeve). This increase in outer cylinder wall surface area allows up to 40% more water to contact the sleeve than was previously possible before now. This promotes much more efficient and increased heat transfer away from the cylinder into the coolant. Which means a much more stable core cylinder temperature under extreme conditions than ever before. The more stable the temperature the more power is available. Excessive heat robs power can cause detonation and shorten engine life dramatically. All our new 250 and bigger kits as well as most of our larger bore engine kits are designed with better cooling in mind,

You can't increase displacement without considering the extra heat that is generated by the bigger bore bikes. For example if you look at a stock KTM or RMZ 250 cylinder the water jackets are less the 1.25" tall the rest of the cylinder about 2/3rds is oil cooled. All our 250+ cylinder sleeves have our Cool Flow Technology. Our design keeps the core cylinder temp more stable by providing an additional 8 square inches (in the 250 kit) of outer sleeve wall to water contact when compared to stock or any other manufacturer. In all testing a stock bike will boil before one of our Cool Flow kitted big bores.

For additional protection we are offering our Cool Flow design for most late model stock configurations.