Well, golly, I think this thread has run it's course and maybe it's time to wrap it up with a few thoughts.
The balancer lever and the idea of replacing it as a bit of preventative maintenance can be a controversial one. Some beleive it is a "must doo", others a "should doo", and others that it's "doo-doo, an urban myth". Then there's the cost, which some perceive to be pretty high for what it is.
On the side of those who do believe are plenty of reports of slack springs happening early on with the Gen 2 bikes and reports of lever failures on the Gen 1s. Failed levers can allow the chain to go completely slack if the top of the lever breaks off, and slack springs allow the same to happen, just more slowly. And then there is the issue of broken bits running around in the side case before they drop into the sump. The problem is seen to be common enough that many feel it is prudent to go in and take care of what they perceive to be a potential problem. The video in the first post in this thread is but one example of the issue with the Gen 2 spring. Pictures of broken levers
and chewed cases
aren't hard too find, either. We've got a few on this forum.
On the side that doesn't believe it is a problem with the balancer adjustment lever is the following, and I'm making up numbers but I believe them to be pretty true.
95% of the KLR650s ever made have never had an engine get damaged by the balancer system, or at least that damage is either not reported or insignificant. That is, in part, because a great many of them never see any significant mileage, like like a lot of motorcycles. How many times have you seen a cherry 10 or 15 year old bike for sale with less miles than you ride in a year?
It's due in part because even a slack balancer system can operate for many miles without causing damage. It may make a grinding noise, but it develops gradually and the KLR is such a rattle trap anyway that the noise go unnoticed.
It's also due in part because it happens and we don't hear about it. There are a couple hundred thousand
KLRs that have been made over the past 25 years. There a but a few hundred
active KLR owners on these forums. When the forum guys' balancer causes problems, we hear about it. When their springs are slack, we hear about it. That is the internet magnifying the perception that all
levers blow, it's only a matter of time..
And many KLRs are maintained by factory mechanics or good home mechanics who don't tighten the crap out of the adjustment bolt, thus deforming and eventually breaking the lever. I honestly believe that, on the Gen 1 bikes, one of the common failure modes is breaking the bottom of the lever by over tightening. The top breaks off from vibration and causes great grief quite quickly. Breaking the bottom often causes the lever to be stick and be stubborn to adjust.
So, you see, there are reasonable positions to be taken on both sides of the argument. However, like guns, religion, and politics, people believe what they believe and an argument on an internet forum is not really going to move them into another camp.
As to the expense, most don't feel that $140 is too great a price to pay for the peace of mind it offers. The problem, if one perceives a problem, cannot be solved on the Gen 2 bikes for $6. In order to replace the spring the rotor needs to come off, and that requires tools. The tools make up the vast majority of the $130. Many people borrow the tools or get the job done at a tech day and avoid that cost. The lever kit is about $40. The issue is that, once you're in far enough to remove the spring, you might as well replace the lever and install the torsion spring, as it will never run out of pull as a linear spring can. Here's a video about the balancer chain tensioner, and in it there is a bit about why the aftermarket lever and the torsion spring may be beneficial.
Each owner needs to do what he believes right for his own machine and should let others do the same. After all, none of these forums are called KLRDoohickeyForum, are they?