Is a 144 big bore kit worth it?
A well constructed 144 can do very well. I would say the athena is nice in the sense its complete and “bolt” on (though its not truly bolt on) its a decent value, but if you can have your cylinder worked over to a 144 then you can get more power than the athena kit.
What comes in a big bore kit?
A big bore kit typically consists of a new larger bore cylinder, piston kit, and top end gaskets. They replace your stock Original Equipment Manufacturer (OEM) parts and increase horsepower and torque by increasing the engine size (displacement).
How much HP does a yz250 have?
2021 Yamaha YZ250 Specifications
| ENGINE | |
|---|---|
| Engine | 250cc single 2-stroke, liquid cooled, crankcase reed-valve |
| Power | 49 HP |
| Bore x Stroke | 66.4mm × 72.0mm |
| Compression Ratio | 8.9~10.6:1 |
Can you bore a yz125 cylinder?
You can get a bored out cylinder that’s 144cc’s, but to actually perform like a 144 it will need some tuning. This is why you will hear positive and negative comments from people who modify their 125 to a 144. Most of the time, it’s the people who buy just a cylinder kit that give bad feedback.
How fast is a big bore kit?
It’s running great, averaging 45-50 mph, and only dropping to around 35-38 mph on hills.
When did the Yamaha YZ-250 big bore kit come out?
L.A.SLEEVE presents the latest Two Stroke Big Bore Kit: the YZ300 Kit for the Yamaha YZ-250! This kit will cover years from 1999 thru 2017. You already have your “KTM beater” in your stable waiting for this hop-up!
How big is the rotor on a Yamaha YZ250?
The 2017-18 YZ250 comes with a 270mm rotor, but for every other year YZ you need to buy your pucker power. This is Galfer’s oversize brake system.
How much does it cost to change Yamaha YZ250 to yz300?
You will gain horsepower paired with a massive increase in torque. L.A. Sleeve does all the work to turn your YZ250 into a YZ300 and the price is a reasonable $1140. the Moto Tassinari reeds, Pro Circuit pipe, Hinson clutch, Torc1 shifter and IMS pegs are extra. Will you need to re-jet the carburetor?
What kind of suspension does a Yamaha YZ250 have?
As long as an old-school YZ250 comes with Kayaba SSS suspension, it will get top dollar from riders looking for an easy-to-ride, easy-to-maintain and easy-to-live-with two-stroke. But, what if you want a little extra oomph out of your aging YZ250?