The Kawasaki KLR650 has been around for many years and is a true workhorse or as some would like to refer to it “Mule”. It is most probably amongst the best selling motorcycles in the world. Although there has been a couple of upgrades over the years the KLR650 is still fairly old technology. It does nothing exceptionally well but it will go on for ever and herein lays it strength. There are many KLR650’s that has done more than 150 000 miles on the original engine and still going strong.

In some places the KLR650 has cult status. In the authors world it is one of those motorcycles that is different in just about everything. You come to love the KLR650. Occasionally you hate the darn thing and sometimes you sell it only to buy another one a month later. It grows on you.

KLR650 Minor Engine Upgrades

Over time the engine has been slightly refined. Nothing significantly especially if compare to some of the other single cylinders around. There are many modification available for the KLR650,  some of them great and some of them maybe not so great.  Some of these modifications claim performance increases not backed up by any results other than the old bud dyno. Many of theses modifications are done at the same time and it can therefore not be determined which modification did what. It is amazing how desire, a little effort and the addition of a little noise will make you believe that there is something when there is in fact absolutely nothing.

We set out to test theses modifications in a controlled environment and on our own personal KLR650’s. Why you might ask? Because we are old farts with time on our hands, quality equipment available to us and nothing ells to do. For some a flow bench and a dyno test does not mean anything but in reality theses tools, when properly used, can and will help to have a clear understanding and indication of what the final results might be.

Nothing done here is to “discredit” anybody. We respect those that has come along before us and done some great stuff with the KLR especially those who made available performance and other parts for the KLR.

2004 KLR650 Dyno Run in Stock Form

First run of our bone stock the 2004 KLR650 with 2553 miles on the odometer.

KLR650 Airbox Jetting and FMF exhaust Mod

First stage mods consisting of KLX needle, 142 main jet, air box mod with 2/3 door removed, FMF Power Bomb and PowerCore4.