HEADS UP!!!

Site upgrade in progress... Core site functions are working, but some non-critical features/functions will be temporarily unavailable while we work to restore them over the next couple of weeks.

Please post any bugs you encounter, but before you do, check to see if it's already listed.

Thanks for your patience while we work to improve the community.

Sign in to follow this  
Followers 0
chuckinketchum

mo power fo 2001 XR650R

2 posts in this topic

I did the standard uncorking but I want more. What engines mods are done to these bikes to make them rip? I want more power. I only dual sport this bike and sometimes the dirt roads are are straight.

Share this post


Link to post
Share on other sites

Here's some inexpensive mods...

* Side Panel Cutout *

The side panel cutout will increase the HP from ~4,250 RPM on up and improve the torque from ~3,750 RPM on up without sacraficing anything on the low side on a properly jetted bike from what I've seen in dyno printouts. If the bike isn't properly jetted, then you may increase the off idle hesitation slightly if you whack open the throttle from down low. Careful tuning can minimize this, but a pumper carb will take care the off idle hesitation completely if properly setup and will generally add a bit more power through improved efficiency. The negative issues from doing the side panel mod is that you'll hear more intake noise, you'll be more subject to getting the filter wet since the side panel will be open and your filter will get dirtier quicker. You may also have to fiddle with your tuning your carb to further minimize any increase in off idle hesitation.

* CAM *

A stage 1 Hotcam only costs about $100 to $130 and it will increase your mid range power without sacraficing anything down low. A stage 2 Hotcam will increase the mid range power with an emphasis up higher, but at the cost of some low end performance. The Hotcams are pretty easy to install, but you loose the auto decompressor, so you'll have to make certain you kick from just past TDC or risk the kick start level kick back at you.

* Gearing *

Dropping a tooth in the front or going to a larger rear sprocket is a quick, easy & inexpensive way to increase your performance & acceleration (at the expense of top speed), but there are awlays trade offs to be made just like with most anything.

* Exhaust *

A larger exhaust header will generally improve the power up top, but at the expense of some power down low. If you're spending most of your time in the upper R's, then this may be something to consider. The stock exhaust system is very good in my opinion for most folks and you can quickly remove the tip or the whole end for maximum performance, but at the expense of noise.

* High Compression Piston *

If you don't mind getting into the engine and possibly using a higher grade of fuel, then consider a higher compression piston.

That's about all that comes to mind right now while quickly typing this before I leave, but these bikes can be built for serious power through a competent & experienced engine builder who knows how each component will behave with each other so that a planned & desired outcome is acheived. Just throwing performance parts together doesn't always produce the desired outcome, which is where experience & expertise comes into play. The XR680 that Rob Barnum builds is an awesome machine that's also super durable, but it doesn't come cheap. That bike simply rips even when geared at 15/45 :thumbsup:

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0