Bruce
Ogilvie’s list of tips on things American Honda has discovered or learned over
the last year of testing and racing the big XR.
THINGS
RACERS NEED TO KNOW
·
Read and follow carefully
the February/March
Wrench
newsletter for conversion to full power competition mode and for right footpeg
installation. They recommend checking the right footpeg bolts for tightness
on a regular basis, about 300-mile intervals.
·
Final drive gearing of
14/45 for BITD and 15/48 or 15/47 (Mexico) for SCORE events offering a smoother
power delivery and the best (forwards) wheel placement. (Stock is 14/48)
·
Remove the brass reserve
from the petcock and run in the on position.
·
Do not use a rear mousse
or tire insert. Use only a heavy-duty tube.
·
If you use the stock fuel
tank, you must remove the white plastic insert so our (Honda pit) dump cans are
able to completely fill your tank.
MORE
TIPS FOR EVERYONE
·
The air filter is held
securely in place by the left sidepanel. Be sure the front lower clip has
adequate tension. It can be bent or damaged by a riders boot or other impacts,
which decrease tension on the air filter and can result in dirt bypassing the
air filter at the front lower corner.
·
With only a 1.7 quart oil
capacity, usage becomes more critical (1 pint low is more than a 25 percent
reduction in total capacity). Be sure to check oil levels in 200-to-300 mile
intervals. To get a proper dipstick reading, the engine must be left at idle for
20 to 30 seconds. When racing, idle into the pit on which you plan to check the
oil. Also watch out for overfilling; too much oil can destroy the crankcase
seals.
·
A stock XR650 will run
better on pump gas than a high-octane race fuel, which needs a higher compression
ratio to be effective. (All gas in the Honda pits is Chevron 92- or VP 93-octane
unleaded.)
·
Keep the rear wheel
adjusted as far forward as tire clearance allows. The bike turns and handles
better and is more stable with the wheel adjusted closer to the swingarm pivot.
·
The stock chain uses a
staked/clipless master link (endless chain). A bike with this much torque will
break conventional clip-type master links. Using one is asking for a race
failure.
·
Honda sells the D.I.D 520
ERV2 chain (0-ring with staked master link). The Honda part number is
DIDS2OERV2-120. Team Honda has been using this grade of chain since 1994. A
special tool is required for staking the master link (also available at your
Honda dealer). The stock XR650 chain is also very high quality and meets or
exceeds the ERV2 strength measurements.
·
The rear fender bolts tend
to come loose and should be checked regularly or have a thread-lock applied.
· Inspect on a regular basis the spring-loaded part attached to the choke plate on the carburetor rear intake opening. If the spring breaks from fatigue (from excess running with the choke on or half on), it can lead to the flapper being drawn into the combustion chamber and cause engine failure. An alternate solution is to remove the flapper and spring from the choke plate, which can be done while still in the carburetor. The only drawback is the bike might take three kicks to start when cold.
·
The owner’s manual is
incorrect: reserve is actually 0.53 gallon.
·
Install a second rear
rim-lock in the rear wheel. Safety-wire spokes in both wheels after break-in
(tighten spokes and balance wheels also).
·
If you have experienced a
boil-over situation with your coolant, consider switching to a radiator cap with
a 1.6 or 1.8 rating (stock is 1.1). Honda doesn’t make a 1.8, but a KX8O cap
is rated at 1.8 and will fit. The downside to going to a higher rating is it
puts more pressure in the system, especially the hoses and fittings.
This increases their susceptibility to punctures and other damage.
Remember, this liquid-cooled bike should not sit and idle for long periods
without airflow through the radiators. Additionally, the system is designed to
boil over and has a coolant catch to handle the escaping fluid.
This does not equal overheating, a common misconception.
·
The Baja race bikes use a
1.8 cap without the overflow tank and thermostat to save weight. They are able
to get away with this by careful bike warm-up and racing with the bike wide
open. These mods are not for the average rider!
·
The power-up kit is the
same as used by Johnny Campbell and company and adds about 10 horsepower with a
higher-compression piston, different cam and a stronger cam chain.
·
Honda also leaves the
chain guide alone because it believes the polypropylene part will flex with
a hit, while a metal guard will bend and do more damage.