Gen 2/3 big bore questions

So I am selling my 450X and will be adding another 2t to the stable. I have not ridden a CR250 in a while so I am looking for some more info. I ride big bores (CR500's) and a YZ250, my buddies all ride thumpers, quads or big bores also so there are not any 250's for me to compare to. It has been a while since I have ridden a CR250 but I remember the 01 being stronger on bottom and the gen 3's stronger on top. I know set up has a lot to do with it also. I do not ride much technical signal track and I do not ride MX. I ride with guys that race Hare Scrambles and that is the kind of riding the new bike will be for. The 450x is great for that stuff but I hate how heavy it is and I am always waiting for the big money rebuild. :thumbsup: The replacement bike WILL end up over 250cc's as I am 245lbs without gear (when bulking) in colder months and down to 220lbs (cutting) when its pool time. So I need more HP year round to hang with my skinny friends. I am considering a KTM300XC also but the PDS isn't designed for fast deep whoops. I am also thinking about a 295 kit for a YZ. So my question for this thread is, what differences can I expect between a gen 2 or gen 3 with a big bore kit? Should I just stick with the YZ? So far I am leaning towards a 00-01 motor in a gen3 or modifed CRF250R chassis. What do you all think?

Also, how do the 00-01 CR250's start compared to the gen 3's and newer YZ's? My CR500's all have a pretty weak spark and I have to kick em like I hate em. I modified a 98 CR250 ignition for my 01 CR500 and it starts a lot easier but still not easy. My YZ250 will start easily in flip flops. I have Rheumatoid Arthritis and after a long day of hard kicking on the 500, my right knee hates me and it makes riding extremely painful somedays. That is why I bought my 450X and I am looking into a newer KTM.... E-START!!! I can kick the YZ all day long and it wont affect me until I rest for a while.

Not selling the 500's only the 450.

I am on both 500 sites and I am going to have the decomp done soon also.

I'm interested in this topic as well and am also 220-230lbs. I just bought an 02 cr250 as my cheap alternative to a new 300xcw-e. I see 295 kits for yz's, but haven't seen anything along the same lines for the cr (case reed) other than a 265. Will having port/head work done give a worthwhile power gain or is big bore the only answer? Peak HP gains aren't a concern, I'm more interested in gaining low-mid without losing top end.

I see 295 kits for yz's, but haven't seen anything along the same lines for the cr (case reed) other than a 265.

Reportedly, the best engine combination for the case reed CR250 is the +2mm overbore (265cc) combined with a +4mm crank stroker to give a total dispacement of 280cc. Rick Peterson used to build these. If you do a search, you will find some interesting information.

RPMmfg and hi tech horsepower have a 290 kit for the cse reed 250.Derek at hp bikesis gonna have a 350cc kit for the non case reed engines.

RPMmfg and hi tech horsepower have a 290 kit for the cse reed 250.Derek at hp bikesis gonna have a 350cc kit for the non case reed engines.

That sounds sweet! That would be a perfect engine for a gen 3 chassis. I have heard that the LA sleeve 330 kits are not that great... but I have never ridden one or known anyone to own one... Just internet talk and we all know how accurate that can be.

Is there a website for for HP?

HP bikes is the site.Dereks 350 kit is not an la sleeve kit it will be his own castings he has made with his own design of porting,head pipe etc..:thumbsup:

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