Fuel For Thought
by Rod Morris
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is prohibited without the express written consent of the author. For more information or to request permission to publish this
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Welcome To Fuel For Thought
Note: Due to time constraints, Webmaster Mark at www.multisurfacemotorcycling.com will
no longer be adding a monthly "Fuel For Thought" article. He will however, continue to
maintain the website with its treasure trove of informative articles, procedures, and all of
the past Fuels. MMP will still operate its storefront from the site as well. We want to take a
moment to thank Mark for all of his hard work. If you have ever worked on a website, you'll
know how much time and effort it takes to compile a site like MSM, especially one that is
well-organized, attractive, and functional. Thanks again, Mark!
Written by: Rod Morris
Glossary of terms and abbreviations:
MSM - multisurface motorcycle
ST - suspension triad (seat, shock aborber/forks, tires)
MMP - Multisurface Motorcycle Products
TGMP - Top Gun Motorcycle Products
MSM Weight Classifications (w/3 gals of gas):
Lightweight (LW) - up to 250lbs
Middleweight (MW) - 251lbs - 300lbs
Light-Heavyweight (LHW) - 301lbs - 350lbs
Heavyweight (HW) - 351lbs - 400lbs
Top Gun Custom KLR650 Rear Shock Springs; 1987-2008
6.6 kg, up to 675 lbs GVW
7.4 kg, beyond 675 lbs GVW
*GVW includes rider and full tank of fuel.
- Straight wound springs made of the highest quality materials available.
- Excellent fit allowing installation from either end of the shock.
- Spring length designed for compatibility with the stock pre-load mechanism.
- Springs are powder-coated: yellow for the 6.6kg and white for the 7.4kg.
If you’re tired of the upside down ride height and resultant 2.50 inches of usable rear wheel
travel provided by the wimpy 5.0 kg stock KLR650 rear shock spring; then contact MMP
and order your Top Gun custom shock spring today.
Remember, the only way to get achieve proper ride height without losing suspension travel
is with a proper spring.
For those of you that don’t subscribe to “Cycle World”, you might want to pick up a copy of
the November 2007 issue. There are two interesting articles worth reading. Page 81 has
an article about the 2008 KLR650 with a half page on the 2007. The most interesting
article is on page 127 and that’s what I want to talk about.
Most of us have gone through the, “I want more horsepower” phase some time or another;
especially when under powered singles are involved. Here’s one example of what you
The owner of a Honda CRF-450R saw an ad for a claimed 40% increase in power (in his
case 50hp up to 70hp) with a 525 kit ($2742). He couldn’t resist. He had the kit installed
and upon the first engine start, it immediately locked up solid. He took it apart and
discovered that the piston skirt was too long and had jammed against the flywheel at
bottom dead center.
The Company rep simply said, “Sorry for the piston fit. We’ll send you a correct one”.
They did, although it took several months.
There were no problems with the new piston. After assembly, the motor fired right up, and
following a few heat cycles, the CRF was put on a dyno. To his dismay, the motor made
the same 50 horsepower it had when it was bone-stock.
The company said it wasn’t their fault; the motor is just an air pump and needs better
breathing. So larger valves were installed and the head ported and because of the longer
stroke, it needed a programmable Vortex ignition. But as soon as the engine fired, white
smoke began pouring out to the exhaust pipe, a sure sign of coolant getting into the
The motor was again taken apart, double checked and everything put back together.
Within 10 minutes of running, milky-white oil was visible in the sight glass and smoke was
once again puffing from the exhaust.
The Company told him that the engine had too much compression and should have the
piston dished to lower the ratio, which he did. This too failed and the engine still leaked
water into the bottom-end.
The Company recommended another place to take the motor because they had
considerable experience with the Company’s products. After another long wait the shop
told our hapless owner, “You need a new motor. This thing will not stay together. We’ve
had all kinds of problems with their cylinder kit-sleeves dropping out, cylinders not sealing
and leaking water. We’ve had to eat the cost at least nine times because they have no
warranty on parts. They just say, “It’s not our fault”.
So now the CRF is back to stock and running perfectly. Quote: “I wasted lots of time effort
and money, only to be tuned to a complete standstill. Maybe 50 horsepower isn’t so bad
I can sympathize with this owner because I too went through the “I want more power”
syndrome on a bike I had. Not as bad as this poor guy but still not much fun. Broke down
twice in Baja which caused (friend) Elden to go get his truck and trailer to haul my sorry
butt back home. I lost all motor reliability, got less gas mileage, cost time and money, and
got to the point of being afraid to go on long rides far from home.
All my equipment now stays as close to stock as practical except for things like a better air
filter, improved suspension, stock carburetor, except for air screw adjustment (no jet kits or
air box cutting) and custom built seat.
My keep it stock 1996, 48,000 mile KLR has never had the top end off, still gets 50 mpg,
doesn’t use hardly any oil and has never let me down.
Is stock best -- you bet, just ask the CRF guy, me and numerous others that tried to get