I ordered the Laser Pro Duro together with the Dynojet jet kit and K&N filter
from Fred Hink at Arrowhead Motorsports. But due to typical handling by USPS, I
received the Laser exhaust a couple of days before the jet kit and filter.
Not willing to wait, I installed the Pro Duro first. This is on a stock 1999
KLR650, stock filter, stock jetting. Installation was simple, but the
intermediate clamp provided is too big and needs the 1 7/8 OD X 1 3/4 ID
muffler bushing that others suggested getting. I had some leftover
cut-your-own header gaskets that I lined the inside of the clamp bracket with,
and this seemed to work well enough. Once everything was tightened and put
back together, I took it out on the freeway. With the stock filter and
jetting, the pipe is only a little louder than the stock one, but the sound is
deeper. I felt a little difference in the performance at low- and mid-ranges,
but the freeway blast at high-speeds felt like the high-end range was the same.
So just as a slip-on with no other changes, performance is definitely improved
(though slightly). Personally, I think its deeper tone is itself reason enough
to get the Pro Duro.
When I installed the jet kit and K&N filter, performance on the bike kicked up
another notch. I put in the Stage 2 jets and drilled hole in my airbox for
better flow to the new filter. With both modifications, the Pro Duro becomes a
little louder, especially around the 6K rpm range, but still well within
old-fogey tolerance levels. It sounds almost like that of a V-Twin (Ducati or
Honda, not Harley). Low- and mid-range power is noticeably even stronger, with
the top-end being a little better also. The bike definitely runs cooler and
revs more quickly. Following the Dynojet instructions for Stage 2 jetting
exactly, the bike runs well with no backfiring or surging, but the Pro DUro tip
is a bit sooty. However, the new power is fantastic! It's no R1 (obviously),
but I think my KLR is now quicker than my two-stoke RZ350 (and this is no
slounch bike!). Might even be worth doing a trackday on this bike now!
I highly recommend the Pro Duro, whether you plan to re-jet or not. It does
make a performance difference and it looks and sounds superb!
On a separate note, I got the MAP Engineering oversized braking rotor and
Progressive fork springs from Fred also. Along with the Galfer SS lines
(previously installed), the bike stops like a streetbike should now. If you
primarily do streetriding on your KLR (as I do), I suggest getting the braking
and fork enhancements first. It's better going fast when you know that you can
stop in time!