KLR Subframe Bracing

Henry Nottingham, House of Motorcycles (619 229-7700), stellar parts guy who has been
selling me motorcycle parts and accessories for “nigh onto” 37 years recently called and
asked if I would try to help “Nick”, a KLR650A traveler. Henry, great guy that he is, didn’t
have a #148 KLR650 main jet in stock but wanted to help Nick whether or not the store
made money.

Sir Henry, as I call him, telephoned me requesting that I help Nick if I could. I called Nick
at the number provided by Henry and arranged to have him come to our home. Once in
my garage I quickly realized that (A) Nick was a pretty sharp guy but, (B) The internet
had claimed another victim.

Nick, who lives at 10,000 feet, had come down to sea level with a grossly mis-jetted
KLR650A. The spout was pulled from the air box, KLX needle installed, #142 main jet in
place and an open aftermarket exhaust system passing “gas” fumes.

Nick was getting by OK at 10,000 feet elevation but at sea level he was running grossly
lean and in danger of damaging his engine. I would like to have furnished Nick with #150
and #152 main jets but since I run stock jetting, stock air box, and slightly modified stock
muffler, I don’t need them.

Nick, being a clever guy, had built his own pelican case racks and installed heavy duty
forks and triple clamps on his KLR. When I asked if he had braced the KLR’s subframe
he looked at me with a scowl and said something like, “Yeah, and what a nightmare that
was! The big drill the kit provided damaged my frame inside the backbone and I had to
do some fancy fabricating and welding in order to save my frame.”

We’ve been warning people for years about this infamous, expensive kit from the
Northwest. The main problem is that the part you drill through is smaller in diameter inside
the backbone. The drill either decreases the wall thickness inside to almost nothing or
may break through if it runs off center.
Pauline and I, with all of our gear loaded onto the KLR650 subframe, weigh 375
pounds and despite logging tens of thousands of off-road miles, have never
broken a subframe bolt. How can that be, you ask. Simple, we properly torque the two
upper sub-frame mounting bolts after applying intermediate Loctite to the threads.
If the bolts don’t come loose the constant 

torqued friction between the assembled parts will do the job. I’ll admit that after hearing all the scary feedback about subframe bolt breakage I installed tougher and slightly longer
bolts, but they’re still 8 X 1.25’s. The key is don’t let the bolts lose torque.

Note how the subframe boss  narrows inside the frame  backbone.

Note how the subframe boss
narrows inside the frame
backbone.

For those who feel they must upgrade the subframe bolts, we recommend you drill and
tap the existing holes for 10mm X 1.25 threaded socket bolts (don’t exceed stock HOLE
DEPTH).
We’ve been recommending this mod for years and ironically, Kawasaki began using 10 X
1.25 socket bolts in 2008.

If tips like this are helpful to you, please give credit to the great teachers I’ve had over the
years; people like the late great Don Vesco, record setting speed specialist; Rob North
and Jeff Cole, frame building; Charles Curnutt, suspension genius and inventor of long
travel suspension; Chuck MacDonald, MacDonald Products – designer and builder of
great foot pegs and shifters; Stig Pettersson, Ohlins suspension whiz; Vey de la Cruz,
master motorman; Alan Dietor, my off-road motorcycle set-up and riding teacher.  There
are some others, but the main point is that we hope to continue giving you helpful and
accurate information garnered from 55+ years of face-to-face relationships with long time
top experts of the motorcycle world. Relying on the internet often doesn’t work.

P.S.

Before we could get this article up, Nick called upon re-crossing the border at the
Mexicali/Calexico Port of Entry. He reports that his Baja ride went well. He and his friends
had two rear flat tires, but no mechanical break downs. All’s well that ends well.

By the way Nick, about 15 years ago Ron Jensen, Robert Buchanan and Pauline Read
(two up with me), rode your beautiful San Juan Mountains including Ophir, Cinnamon,
Schofield and Engineer Passes. We were all too lazy to re-jet for one trip so we ran stock
carburetion. Amazingly, other than being a little down on power, none of us puffed black
smoke or fouled a spark plug. I will admit, Nick, that were I to visit your beautiful Durango
Colorado area again, I would follow the instructions on pages 2-5 of the Kawasaki Service
Manual by installing a #145 main jet and a #38 pilot jet.

In closing, I hope you and your pals had as good a time in Baja as we had on our great
San Juan Mountains trip. Cheers.