As you can see,
this '908' spring fits
just like stock.
The spring needn't have
over 1mm of extension
fully closed.
If needed, the 'tab' at the
lower mounting point can
be adjusted for tension.
Using a good needle nose plier will make removal and installation a 5 minute job.
Don't use a diagonal cutter or scissor...nicking the spring wire can lead to breakage.
Theres no need to remove the carb...install the lower 'loop', then attach the 'hook'.
The I.D. plate or number stamped on
the carb body or web casting will have
three numbers.
All 94/40/XXX numbers are 40mm
carbs, and take the 312 spring.
It seems the 32mm carb #'s changed
from 64/32/XX which takes the 908, to
64/32/XXX which takes the 606,
sometime in the late '78 production run..
There's variation in US and
overseas models, too.
Do a visual comparison
before ordering..
the 606 hook and loop open to
opposite directions.
The different spring types are
NOT interchangeble.
This site is about improving the Airhead experience. This EZ Pull Spring equipped '78 R100/7
was running great, but the throttle grip itself didn't feel quite right, so heres what we did. Most
EZ Pull Spring customers tell us they just put 'em on and go...
The throttle tube and cam gear teeth were
worn at the off idle position, which resulted
in a lot of freeplay at idle, and binding further up
the tach..
The gummy aftermarket grips were about
gone, and slipping around the throttle
tube, which goes to show what you can get used
to. We ordered the new tube and cam...the tube
comes with the original  Magura style grip
installed, so another one was ordered for the left
side. Theyre a better design, and way sturdier
than any of the aftermarket grips we've seen over
the years. Cheaper, too. We usually get our parts
Ted Porters
The 'American' style bar ends were caked with
a mixture of grease and ground anodized
alloy, over some light rust pitting. Not as
sluggish as old chain wax, but close. We
scraped off the chunks, sanded with 220 grit,
then gave the bar end a couple coats of high
perf auto wax rather than grease. The tube is
a fairly loose fit, and we mainly wanted to seal
the end from further oxidation. The wear on
the housing between 6 and 12 o'clock was
probably where the cam gear was binding,
and had to be smoothed down a bit.
Line the register marks up. If the teeth dont
mesh, its because the bar end is hitting the
grip end. Loosen the 4mm Allen bolt under
the pod, and move it towards the bar end.
When its done, about 1 or 2mm of freeplay
along the grip length is don't want
to be grinding up any rubber.
Get the little stuff right, and the big stuff
usually takes care of itself, for a while, at
Make sure the cables are routed cleanly,
and without binding. Absolutely critical.
Install the cable ends, and give the chain
and gears a shot of lithium white grease.
Pull the lower cable sheathing back, and
seat it in the housing, then the same
thing with the upper cable in the cover.
Make sure the register marks line up,
and the tab on the cover fits easily in the
groove of the throttle tube. Don't force
anything, and don't try turning the
throttle till the cover is secured with the
oval head retaining screw, which should
be 'snug'.
Not all of this will be necessary for the
springs to work properly on most bikes. The
R100/7 this work was done on has at least
120k miles, and a lot of delayed
Now the throttle can be easily turned with a
thumb and forefinger, and snaps completely
This '83 R100RS would
typically take the '312' spring.
"Wow! What a difference the springs made! And to think I
have been riding this bike for the last six years with those
stiff springs..
Thank you for a great product, and have a great day."
Mark M.