|
Jay VanValkenberg got sick of waiting for
Honda to get off their duff and offer a big bore thumper ATV. Jay has been
riding a big bore TRX250R for years. He bought it brand new back in 1989 and
finally decided to switch over to a 4-stroke. Being a die-hard Honda fan he
wanted a thumper that had plenty of torque and plush suspension. He decided
a fully built TRX450R wouldn't satisfy him so he decided to build his own,
fully custom TRX680R!
Jay bought a
XR650R motor from desert racer Mike Kay. The motor was built for a reliable
desert racing motor by Rob Barnum of Barnumspro.com. It features a Carrilo
rod mated to a custom 10.25:1 Wiseco piston (680cc) with Kibblewhite
titanium valves and springs, a stage 2 HRC cam, hardened rocker arms, HRC HD
cam chain, machine balanced crank, a 200 watt stator, and an all new clutch
and rebuilt transmission. The motor came with a 36x42mm Edelbrock
carb and a Big Gun exhaust. Jay bought an FMF exhaust, but ended up
switching to the Big Gun for more power.
Jay decided to have the frame built by Keith Marx of
Motoquadchassiscomponents.com in Oregon.
It?s a custom, one-off, chromoly frame, swingarm, a-arms, steering stem, and
various other parts. Jay wanted the frame's geometry set-up similar to a
TRX250R as well as being able to accept 250R parts. Keith went to work and
came up with an amazing frame. It's a work of art! It features +2/+1 long
travel a-arms and a 2" over '89 style no-link swingarm. For shocks he had
TCS revalve an Elka shock to be used in the rear and had a custom set of TCS
shocks built for the front. TCS claims 11" of travel in the front and 12" in
the rear!
For spindles and brakes Jay used some of his left over stock 250R parts and
topped them off with HardKor front hubs and Braking rotors. In the rear Jay
used his RPM axle, bearing carrier, and anti-fade axle nut which he had on
his 250R. Jay topped the project off with an IMS 4 gallon tank, FuelATV.com
front bumper and rear cooler rack, and a shiny, new set of red FullBore
plastic!
It took several months to complete, but once it was finished; and a few bugs
were worked out; it turned out to be a monster of a machine! During a recent
trip to the St Anthony sand dunes in Idaho, Jay got to dial this beast in
and give it a good test run. He had to work out a few bugs with the major
one being starting the XR motor. Due to the frame design, the OEM kick
starter would not move downward far enough to allow the motor to start. The
1st few rides he had to be tow-started. Jay planned on adding an
electric start kit from Baja Designs at some point, but ended up having it
shipped to Idaho and installing it there. Once it was installed and set-up
properly this electric start kit worked perfect.
Riding this beast you soon realize it has tons of torque! You can lug it
down to a near stall in 3rd gear, hit the throttle and it roars
back to life. The long travel TCS suspension with a no-link rear suspension
is ultra plush. The frame design allows this TRX680R to turn on a dime with
zero bump steer. No steering stabilizer needed!
Jay is very happy with
his creation. It is set-up perfect for him, has plenty of power and
couch-like suspension. It should turn out to be an ultra reliable dune
machine which is exactly what Jay wanted when he started this project. Take
note Honda, there is a market for a big-bore thumper!
|
Engine:
Engine built by Barnumspro.com
680cc custom 10.25:1 Wiseco piston
HRC crank with Carillo rod , machine balanced
HRC stage 2 cam, HRC cam chain
Kibblewhite Ti valves and springs with hardened
rockers
Edelbrock 36x42mm Quicksilver pumper carb
Clutch: Stock XR650R
Exhaust: Big Gun modified for clearance
Machine balanced flywheel and counter balancer
Bajadesigns E-start kit
Electronics:
XR?s only CDI
HRC coil
Spectrum 200W stator
Stock XR650R wiring harness
Trail tech regulator rectifier
Trail Tech MR-11 HID?s
FusionXtreme billet tail lights
Controls:
Bars: Flexx
Throttle: Moose thumb throttle
Clutch perch: Works Connection
Decomp lever: Works Connection
Brake lever: 250R custom trimmed.
|
Chassis:
Frame: Custom by Motoquad Chassis Components
A-arms: custom +2+1 long travel by Motoquad
Swingarm: +2 '89 250R No link long travel by Motoquad
Steering stem: Custom by
Motoquad
Front suspension: TCS
19." long travel triple rates 11? suspension travel
Rear Suspension Elka no
link body, revalved and resprung by TCS 12" suspension travel
Spindles: Stock '89 250R
Front Hubs: Hardkor
Rear hubs: stock 250R
Brakes: Stock 250R (front and rear) with Braking rotors and pads
Rear axle, bearing carrier and anti-fade nut: RPM
Front bumper: FuelATV.com
Rear rack : Fuel ATV.com
Powdercoating by
BlakelyKustomKoatings.com
Plastic: Fullbore 250R
Fuel tank: IMS 4.0 gallon
Radiator: Afco Dual pass
250R racing radiator
Fuel cap: Project 321
billet/carbon fiber
Tires and Wheels : ITP
Pro series Baja wheels Skat trak Hauler extreme 9 paddle rear with Sand
Star front dual rib.
Misc.
Gearing: 14/39
Chain: DID Roadrace X-ring endless chain
Airbox: custom with 250R K&N filter
Nerfs : Blingstar Dana
Creech style
Oil tank: Custom by Motoquad
Oil cooler: Earls 7 row
Temp-A-Cure
Oil lines and fittings: XRP Braided stainless
Estimated weight: 375lbs
|
|
Your Privacy Choices