Sport Tuning Tips
some Triumph Thunderbird Sport tuning tips from "J.B.":
I live in England and have
a '99 T'Bird Sport.
Couple of hints for you,
just reading the excellent article on valve clearance
adjustment, which I had a go at myself not so long ago.
Couple of things I found out about this engine:
I really do understand the
frustration with the lack of clearance under the frame
tube, so I found that it is really much easier to remove
the coolant junction pipe that is bolted to the left hand
side of the
cylinder head, it takes two minutes, and whilst still
attached to the hose, it will fold neatly out of the way
to allow you to work. Once removed, dry thoroughly
around the mating area and when bone dry cover the hole
with gaffer tape, err, believe me stuff can fall in there!
The engine goes
"quiet" when the valve tappet clearances are too
tight! Honest, so be very suspicious of an overly
quiet engine - the healthy rustle is what you want to
The engine power is largely
restricted by the awful exhaust system (especially the
downpipes/header pipes), and of course the standard
- Exhaust - I had a set of
custom stainless downpipes made that run into a large
(but handsome) 3 into 1 large collector, to allow
expansion, these were then mated to the custom
silencers (mufflers), made for me by OS
Hixon, Staffordshire, England. The difference
that this mod alone makes is very noticeable. (See
Exhaust Systems page)
- Airbox - if you look at
the airbox, you will see that the engine is trying to
breathe through something like a 1.25 dia pipe.
Not enough volume perhaps? That's what I thought
anyway. K&N make an air filter kit for the
bike, they just fit individually to each carb.
They are pucker filters so damage to the engine
bore/pistons and rings etc from particulate matter
should not occur if fitted properly. Then all I
would suggest is checking the mixture to make sure you
are not running lean. No one at Triumph or
Wilcox will confirm this (to busy trying to sell you
cams and engine work..................), but I believe
that doing these two mods will give you in the region
of 80BHP at the back wheel, maybe a bit more or less.
I'll let you know when I've done a dyno run.
Best Regards, J.B.
Thanks J.B. for sending