Home
Basic Dirt Bike How-To's - Video
Dirt Bike How-To's - Video
Living The Moto Life - Video
Bike Tests | Shoot-Outs - Video
Forums
What's new
Latest activity
Log-In
Join
What's new
Menu
Log-In
Join
Navigation
Install the app
Install
More options
Close Menu
Forums
Dirt Bike Discussions By Brand
Yamaha MX & Off-Road Dirt Bikes
YZF267 v. YZF290
Reply to thread
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Message
[QUOTE="Rich Rohrich, post: 143714, member: 16241"] You seem to be taking this personal and it's not. You asked a question and I gave you an accurate answer. Your concerns about using a steel sleeve in a design like this are well founded. I get really annoyed when companies who are considered "qualified" do brain-damaged work and try to pass it off as a some great engineering feat. My disgust with what these companies are doing to these engines probably comes off as overly caustic towards YOU. That wasn't my intention at all, but experience has shown me that making a strong statement about these types of things is the only way to truly get the point across. Any other tactic and people will be e-mailing for months asking "should I put a steel sleeve in my 250F?". As I've pointed out in previous threads IMHO these engines can benefit from a slight bore increase if your goal is to shift the the torque peak to a lower rpm range. I'm not convinced at this point that the increase to 290 (even with an Al sleeve) is a good idea unless you are willing to trade a lot of high rpm efficiency for a torquey woods bike type powerband. Changes to the cylinder head, cam timing and ignition curve would be required to retain the same rpm capability as the stocker with a bore increase of that magnitude. I haven't seen evidence at this point to make me believe the cylinder head will ever be up to the task. Proper squish clearance, appropriate fuel, and good jetting is all that is really needed to realize this engines true potential. A 2mm overbore just makes the bike more friendly for those of us with less than stellar skill levels. My advice is to wait till you need to freshen up the top end unless you are a racer who truly needs every advantage. [/QUOTE]
Verification
Which ocean is California closest to?
Post reply
Forums
Dirt Bike Discussions By Brand
Yamaha MX & Off-Road Dirt Bikes
YZF267 v. YZF290
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
Accept
Learn more…
Top
Bottom