BY PAUL ONORATO
Give it the shaft
I broke the pull-starter on my Mammoth ST nitro truck and need some guidance on
what to do. I can obviously replace the pull-starter, but some of my friends’ trucks have a shaft-starter that seems to be more convenient. Which route should I take, that is, if a shaft-start even fits
on my Mammoth ST engine? [email]
I just wrecked my side-cut-
ters trying to cut a piece of
throttle linkage. How do I cut
First, look at your truck and make sure there’s enough room to get the shaft from the starter to the
back of the engine. If there is, then examine the pros and cons of each type of starter. A pull-start can
hang up, or you may break the cord or the spring inside the unit. A shaft-start is much more reliable,
but you’ll need to buy a starter, a battery pack to run it, and a charger to charge the pack. So if you’re
willing to invest a little money and can make it work in your truck, go with the shaft-starter.
XTM Sure Start electric universal starter and Sullivan TigerDrive systems make it possible to easily
convert pull-start engines into shaft-start engines. The Sure Start works with XTM, SH, OS, and Force
engines and TigerDrive has systems that fit most . 12 to . 46 engines that can be set in four directions to
accommodate different exhaust and chassis layouts. Sullivanproducts.com has a very helpful engine
cross-reference chart that tells you which system will fit your vehicle. For the Mammoth ST, I got the
inline TigerDrive (item no. S704) and starter wand (S686) that can be chucked into a cordless drill.
Use a Dremel tool with a
cutoff wheel or a hard-wire
cutter. Xuron makes a nice
one for about $15; it’s item
Which servo horn do I use to
put a Hitec servo in my
Tamiya car? I have a Futaba
horn and a Sanwa/Acoms
1Remove the engine from
the chassis and take the
exhaust manifold off to get it
out of the way.
2Unscrew and remove the pull-starter from the back of the
engine, and take out the stock output shaft and leave the one-way
bearing in the engine.
3Lube the gears with grease and
then insert the new output shaft
into the one-way bearing followed by
the rest of the TigerDrive assembly.
Neither. A Hitec servo has 24
splines on its output shaft,
but the horns you have are 25
spline (Futaba, also fits
Traxxas) and 23 spline
(Sanwa/Acoms, which will
also fit JR, Airtonics and KO).
Hitec offers high-quality
horns for its servos, and
Dubro sells quality horns as
well. If you need a servo-saver, Kimbrough can dial
I messed up and installed my
Deans battery plug on the
speed control and vice
versa. Does it really matter?
It doesn’t matter as far as
goes, but the male plug’s
exposed prongs represent a
short-circuit hazard when the
pack is unplugged. Don’t risk
it: reinstall the plugs properly.
4Fasten the TigerDrive in place using
the stock screws, making sure the
gears turn freely. If there is any binding,
loosen the screws, and slightly reposition
the TigerDrive until it spins smoothly.
5The TigerDrive starter wand has a convenient hex ball end, so
you don’t need perfectly straight access to the engine since it
lets you reach it at an angle.
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