On The Pegs March 2019 - Volume 4 - Issue 3 | Page 117

On The Pegs
Vol. 4 Issue 3 - March 2019
THE ENGINE IS
DISASSEMBLED
AND AN EXC
HEAD IS IN-
STALLED.
ENGINE
XPR Motorsports did the moto work on Evan’s Enduro bike,
but John Ross did the motors for GNCC. Here’s John Ross of
RideOnMoto.com talking about the engine modifications.
Basically on the engine we disassemble it completely. We in-
spect for any flaws. We go in and we actually use parts from the
KTM EXC bikes, and then we have to do a little bit of machining to
put them into proper spec. But once we get the numbers we like,
we put them back together. We use the EXC cylinder heads that
have been modified slightly because the EXC heads flow better.
We also use an EXC crankshaft, but we do some work to them to
make them work really nice.
Then we just take some OEM valve springs we switch out. His
bike is completely stock KTM/Husqvarna components, OEM. We
actually use a diaphragm clutch spring from a 450 in it. We just
go all the way through it and I have an engine builder who does
at least four or five of these engines a week. We make sure there’s
no flaws in it. Then we balance the crank and we make sure it’s in
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