- The Question - I have a 90 Banshee with all
the minor bolt on`s. It has a set of FMF pipes,reeds and
spacers,K&N`s,carbs have been jetted #30 pilots and
300 mains,and a boost bottle. Like I said all the minor
stuff is there but I am looking for more. I am very
interested in the after market cool head and the timing
plate. My question is this, are they worth 400 bucks or
not? If I install the head how many pounds of compression
can I go up to before I can`t run pump gas anymore? Am I
better of with an adjustable head or should I just have
the stock head milled a little bit? I`m not purchasing
the head because the machine runs hot I simply want more
performance. Also as far as the timing plate goes, how
many degrees of advance do you run? I`ve heard 4 but I
don`t know. Remember the bore is stock and so is the
stroke? What is gained by the advance, low end torque or
high end horsepower? Also remember that I will be adding
the head also but I`m not sure it makes a difference.
Also I haven`t bought reed cages yet just the reeds.
Again worth the money or not? Any help will gladly be
appreciated. Thank You.
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- The Response - It has been my experience that
the Banshee head can be modified to work well in many
high output applications. From what you have listed as
your setup I doubt the Cool-Head is your next logical
step. The money spent on it could easily be better spent
on porting and modifying the stock head - you'll be WAY
ahead of the game this way. Remember, those billet heads
just came into being a short time ago. Can you believe we
ran high output engines without them just a few years
ago? Did you know the road race crowd doesn't use them?
RZ350 race bikes typically put out about 65 - 70 HP to
the ground - and those races last a long time. Do you
think anyone can run a Banshee engine full throttle for
longer periods of time? Keep in mind that it is common
for the RZ's to be doing just one thing if they're not
accelerating - that would be braking for a corner. There
may come a time when you can actually use the added
cooling ability of the high price head but that time will
be after you've made the commitment to running straight
race gas or at least a suitable mixture of the best pump
gas you can buy and the highest octane race gas you can
afford. And that will occur after you've made the
commitment to make serious power from your Banshee
engine.
-
- Most after market reed cage designs for the Banshee
are all lacking one important feature - a noticeable
increase in reed petal area. The biggest problem with the
Banshee cylinder is that there is not enough reed cage
area, and it can't easily be added. A typical 80 cc or
125 cc motocross bike has more reed cage area than the
mighty Banshee. Though those engines turn higher revs,
their additional area more than compensates for this
design enhancement. It is possible that the V-Force cage
may offer a substantial increase in this area - as of
right now I am unaware of its availability for that
engine. Even with this as an addition I have been told
that while the design offers upper RPM power gains, the
power falls flat on its face when off the pipe. Perhaps
it would be good to be able to stop 2 of the 4 petal
surfaces from vibrating at low revs to account for this
loss. UPDATE See - http://www.mototassinari.com
- Now availabe for the Yamaha Banshee and the Honda
Fourtrax 250R. Notice the new Delta Valve 2 design which
features an adjustable reed stop to allow more, or less
preload on the reeds.
-
- Changing the timing by using an adjustable plate can
be put in the same category as the Cool Head - maybe some
time down the line. Just because a part is available
doesn't mean its replacement is indicated. It also
doesn't mean that you'll notice anything (seat of the
pants or otherwise) by changing the timing. The only
reason to make a change is to prevent detonation or
problems associated with pre-ignition - it has always
been best to run the least amount of initial timing as
possible and use the best combustion chamber shape
available to burn its trapped mixture. If your timing
needs more advance and is indicated through performing
scientific dynamometer testing, look to your combustion
chamber design/shape for answers before looking
elsewhere.
-
- When CNC machinery became common a few years back, a
few people sat around a small round table and secretly
conspired... They thought of all the parts these cool,
ultra precise machines could make if programmed properly.
Soon every part that could be cut from a piece of 6061-T6
aluminum was being cut, from one shop or another. The
target buyers of these products would dig deep into their
pockets, work long overtime hours and spend countless
hours removing perfectly good running hardware from their
machines and replace it with billet parts which offer
better looks if nothing else. They also scurried around
to buy pieces of wood and brackets to be able to have
enough shelves to put the old parts out to pasture on.
Recently, for one machine or another I've seen billet
blocks (not just covers) and carburetors and cylinders.
These trick parts are now not just intended for the
select few that actually need them. It seems that the
public has been sufficiently fooled into thinking it is
these things that make them go faster. In many cases the
difference is NOT NOTICEABLE!
-
- I have always been happy with the output my engine(s)
have made when designed for the correct purpose. Some
people have heard me toot my own horn about the power my
TRX makes, I'm not sorry about that. It rocks!
Toot-Toot!! I have 4 billet parts on my TRX. The reed
spacer which is necessary to use so that the intake boot
will reach the carburetor - I would not run a reed spacer
unless this was indicated by this reed cage which shows
improvement in power on a dynamometer (tests without the
spacer show no gain/loss on the dyno). The other external
billet piece I use is the the Cool Head - its outer case
and the dome (actually 2 parts). The only reason I use
this head is that I may need to run a different
displacement top end or a vastly different combustion
shape during testing and it is so easy to swap out domes
this way. There is no other reason for running one. My
engine shows no power improvement by adding it alone - if
everything is the same as it was before the change.
Internally I have a billet clutch basket because the
original part would wear out in an unacceptable amount of
time. It has proved to be a money saving
- item over the long run.
-
- Most people know that an engine built for running
Baja is very different than one built for running flat
tracks. The flat track engine is very different from a
sand hill racer which is very different from a 300 ft.
sand shooter. All of these are different than an engine
which runs woods courses - more technical tight terrain.
An indoor stadium motocross type engine build is
different still. The thing these engine types all have in
common is that they all fit within a certain category.
They are not on the fence - they are clearly defined.
Sitting atop the fence, trying to choose speed vs
reliability is the correct way to be a spectator a lot
longer. The person who chooses one side of the fence or
the other has chosen wisely enough that he/she has become
clear about their intentions. Their eyes will open bigger
and their mouths will smile much wider because of the
decisive action.
-
- If you want to go the fastest for the least amount of
money make a decision early as to the kind of riding
you'll do and choose the maximum octane you're willing to
buy - everything stems from that. Never call up a shop
and tell them you want a little more power. You'll be the
hardest kind of person to please. Don't try to define the
difference between going faster and going a lot faster,
or going faster than that. Choose a riding style category
and octane.
-
- If time/money is a consideration make choices for
what the ultimate outcome will be - build toward that
target. Don't settle for a different engine
characteristic. Don't lose sight of the goal and don't
let compromise come between what you want and what you
get.
Rick
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