BT-65 Frequently Asked Questions
there any initial break-in time?
Due to the links in the primary chain gliding over our nylon
shoe, you will notice 3 groves slightly wearing on the shoe
until the chain 'seats' itself and the rollers come in contact
with the top of the shoe. This is normal and usually happens
within 400-500 miles. We suggest rechecking the spring compression
measurement once this has occured. You may or may not need to
add a shim.
M6 came with a lot of different SHIMS. Which ones do I use?
M6 box should have 12 shims in it (2 sets, 6 of each). The shims
shaped like a capital "H" are designed for Big Twins
from 1965-1993. The other set has 2 different shapes. There
will be "L" shims and "U" shims (3 of each
in different thicknesses). They are designed for 1994-2000 Big
if the steel guide plate with the block welded to it is too
maintain control over the lengths of the guide plates, we created
a most universal size. In some cases it may be too long. Simply
shorten the length to fit your primary case. This can be accomplished
by grinding the end as required. It is important that once the
guide plate is slid over the bolt, it fit flush from top to
bottom against the factory slotted adjustment bracket with the
block facing you. DO NOT assume you will need to shorten the
other guide plate as it is created shorter in manufacturing.
M6 appears to 'hang out' over the edge of the primary case.
Is that normal?
some cases, the M6 actually extends out past the primary case.
This is normal as it actually sets on the lip of the primary
cover when closed.
there a specifc primary fluid that needs to be used with the
M6 and it's components?
The M6 does not require any special pirmary fluid. The "shoe"
material is designed to be used with any "normal"
primary fluid. Not only do we follow Harley with their suggested
primary fluid, but we also recommend popular after market brands
and have had no instances of brittlness or premature wear when
other primary fluids are used.
"The primary fluid you are currently running will
work fine with the M6".
the SPRINGS ever wear out of get weak? What if I break a spring?
SPRINGS are custom made for us. You cannot buy them in a hardware
store. It is unusual that we ever have to replace springs but
they can always be purchased directly from us.
long will the M6 last?
of our first installations (over 13 years ago) now is approaching
600,000 miles on the M6. He has installed 3 primary chains during
that time, but figures when you can get over 100,000 miles on
a chain you are doing real darn good. AND, he's still on his
is the measurement for the SPRING COMPRESSION area?
from the bottom of the SHOE to the top of the SHIM pack. If
you are installing the M6 on a stroker or in conjunction with
a Fisher Damper, you will need additional spring pressure, so
we recommend the distance be set to 1/2".
many SHIMS do I use?
on the amount of miles on your primary chain, the number of
shims will vary. What is important is to achieve the 5/8"
measurement in the spring compression area. (1/2" if the
bike is a stroker). Start with one shim, then measure the area
between the BOTTOM of the nylon shoe and the TOP of the shim.
If you have a 5/8" measurement, you are done. If not, add
another shim and measure again. The more miles on your primary
chain, the more chain "stretch" you may have had.
Keep in mind it will depend also on how those miles were put
on. Once you are certain you have reached the 5/8" measurement
you will need to keep your extra shims for future use. As you
have chain "break-in" time or "stretch"
you will need to add additional shims to maintain the 5/8"
long can I expect the SHOE to last?
is not unusual to see well over 100K miles on an M6 shoe. As
long as the correct lubricate is used in the primary case and
the M6 is checked for wear every 20,000 miles, you should expect
to have a long shoe life. Replacement SHOES can always be purchased
directly from us. You do NOT need to purchase a 'complete' M6.
if I loose my extra SHIMS?
can always purchase any of the pieces of the M6 directly from
will I know I need a new PRIMARY CHAIN?
the years you will continue to add additional shims as your
chain stretches. When you get to the point that you need more
than 5 SHIMS, it is an indication that your primary chain is
worn and should be replaced. Once you replace your chain, back
off the M6 and start over with a minimal amount of SHIMS to
achieve the 5/8" measurement.
bike is making a WHIRLING sound. What is it?
M6 does not have any 'hooks' into your system. We are merely
providing a surface for the chain to glide over. In some cases,
we have had a 'whirling' sound reported to us. If the M6 is
installed properly and the 5/8" measure is achieved this
sound is simply the chain gliding over this shoe. It will generally
subside within the first 200-300 miles. Most installations don't
hear this at all. If you should, don't be alarmed. It is not
causing any pre-mature wear on your chain or our shoe. You can
reset your measurement to 1/2" and you should see the noise
How often should I check the M6?
the unit for wear every 20,000 miles...always keep clean oil.
tight should the nut be?
the nut to 33 ft. pounds. Add a touch of loctite and you're