Improved Fuel Efficiency
Easy Precision Jet Changes
Adjusts For Altitude and Temperature
Works on Snowmobiles, Motorcycles, ATV's & other vehicles
!!! NOT legal
for sale in California on pollution controlled motor vehicles !!!
except on vehicles used for closed course racing only
or in other states where similar laws apply.
For off-road racing
Not for aircraft use
The Thunder PowerJet fits any size or
brand carburetor. It is exactly what you need to achieve maximum
performance with your engine. The TPJ improves performance by precise
fuel metering with needle valve adjustment. Fuel distribution is
improved by adding fuel through two sources instead of just one. This
means more horsepower at any temperature or altitude. The TPJ gives you
a range of over 10 to 12 jet sizes with precision external adjustment.
PowerJet works great on stock or modified motors, two cycle or four
cycle engines. TPJ can be used on Turbo, Blower or Nitrous equipped
engines. A one way check valve is included which holds fuel close to
the TPJ for extra quick throttle response. The one way valve also
protects against blow back from the engine to the carburetor. The TPJ
can be used with fuel injection by adding a remote float bowl. The TPJ
body is nickel plated to resist corrosion and keep it looking sharp.
The viton seals are compatible with all fuels including race gas and
alcohol. A large knurled knob with an index pointer makes adjustment
easy. Each kit comes with complete instructions and necessary mounting
hardware. Installation is easy and tech support is available.
TPJ-Single - $64.95
TPJ-Twin - $124.95
For more information read
TPJ-Triple - $189.95
Power Jets and Thunder PowerJet
have been around for a long time and are a great addition to any
carburetor. Mikuni recognized the benefit of power jets many years
ago and still offers their version today. With Mikuni's version of
the power jet, you must unscrew the top of the power jet, reach inside
with a screwdriver and start the process of changing jets until you find
the correct combination.
Here is where
the Thunder PowerJet is different. We wanted the Thunder PowerJet
to be user friendly so we placed a knurled adjustment knob right out in
the open. Just rotate the knob by hand counter clockwise for
increased fuel flow and clockwise for less fuel. The Thunder
PowerJet is nickel plated for corrosion resistance as well as great
looks. The Thunder PowerJet is truly a simple trouble-free product
that makes carburetor adjustment easy.
With the Thunder PowerJet installed, the main jet is
decreased by 20% to 25%. The remaining fuel is supplied by the
Thunder PowerJet. This combination gives you great throttle
response due to the smaller main jet's superior atomization.
Throttle response is dramatically increased. Overall power is also
increased for several reasons. First of all, the Thunder PowerJet
can be dialed in so quickly and accurately for any temperature or
altitude that you no longer dread rejetting your carbs. It is
about a one to two minute job. With the Thunder PowerJet, fuel
distribution is enhanced because you are now adding fuel in two
locations instead of just one. The last benefit is increased fuel
efficiency. This is due to part throttle riding conditions where
you are running on the the smaller main jet.
The Thunder PowerJet has a huge fuel delivery range
from zero fuel to as much as a #500 Mikuni main jet. These
adjustments can be made in finite increments as small as a 1/4 jet size
at a time. The Thunder PowerJet has enough range to ride from lea
level to 15,000 feet as well as any temperature variation.
The Thunder PowerJet is ideal for stock engines, mod
engines, big bores, nitrous, blower or supercharger applications.
Any fuel or additive may be run through the Thunder PowerJet without
damage to the seals.
The Thunder PowerJet can be used with pressurized or
non pressurized float bowls. It can be used on any brand of
carburetor. Each Thunder PowerJet kit comes with everything you
need for installation including an excellent installation and tuning
manual. Technical support and information is available at Thunder
Products during all normal business hours.
The only option available for the Thunder PowerJet is a
Deep Well Float Bowl Nut (we recommend it) which will fit on your
carburetor eliminating the need to drill and tap your float bowl.
This also places the Thunder PowerJet fuel pickup further from your main
jet, eliminating the possibility of fuel cavitation between the two fuel
sources. More information at
Deep Well Float Bowl Nuts.
Here's a new twist on an old method; adding a power jet to a carburetor.
Remember those? Simple power jets have been used for years as a method
of improving the calibration on bigger carbs, like what sleds use. A
Power jet consists of a fuel pickup in the bottom of the float bowl,
connected through a fuel hose to a spray nozzle that protrudes into the
incoming air stream going into the carburetor.
How and why is this an advantage? Using a power jet allows you to lean
down the main jet circuit with far less fear that the engine will seize
on top end, as the power jet supplies the rest of the fuel needed on top
end. This has several advantages. Throttle response improves
dramatically, and since most riding is done at partial throttle
settings, fuel economy is improved as well. Power is improved at any
temperature or elevation.
the Thunder PowerJet different from a “simple” power jet is that it is
adjustable! It has a Viton needle valve (needle and seat) for precision
adjustment. It allows for extra fuel to be added to the total fuel
delivery, adding to the fuel from the rest of the carb jets. It can be
set to the tune of adding zero fuel, all the way to adding as much fuel
as a 500 main jet can supply. Think of it as giving you an external
adjustment of around 10-12 jet sizes, minimum! A large knurled knob with
an index pointer makes adjustment easy (and no more digging into the
The strongest fuel signal
is in the 1/2” circle in the center of the carb bore. The further away
you move from the center of the bore, the later the TPJ comes on. Fuel
flow will begin at approximately half throttle delivering progressively
more fuel and reaching maximum efficiency in the 3/4 to full throttle
range. The TPJ will improve mid to top end throttle response and
protect you from leaning out with extended full throttle runs.
The TPJ is great for piped
engines because power comes on at higher than stock rpm’s, so fuel can
be easily added in this area without suffering through a rich condition
in the lower rpm areas. It also works extremely well on turbo, nitrous
and blower applications.
A one-way check valve is included, so
you don’t have to suck the fuel all the way from the float bowl. The TPJ
body and all hardware are nickel-plated to resist corrosion, and the
viton seals on the adjustable needle and seat are compatible with all
fuels, including race gas and alcohol.
Some may wonder how this
differs from a Dial-A-Jet. The Thunder PowerJet is not air corrected
like a Dial-A-Jet, so there’s no mixing chamber or emulsion mixture.
This is raw fuel being delivered here. Thus, the range of adjustability
in terms of total fuel delivered is greater.
Mountain riders can
calibrate their sled to work best at any elevation. As they come down
the mountain they can add fuel to maintain safe ratios. Or, let’s say
you wake up and the temps are colder than your jetting is safe for. No
problem, tweak your TPJ and add some more fuel, quickly and easily. The
options are many.
Add the Thunder PowerJet
to any carbed engine and you instantly gain the benefit of (quick and
easy) external adjustability. Then add to it the benefits of having a
powerjet. Generally, the bigger the carbs and larger the engine, the
greater the performance benefit. Big bore twins are prime candidates
(like ones with 38mm, 40mm or honking 44mm Mikuni carbs). Sleds with
smaller carbs would still see gains and would also benefit from the
comes with complete instructions and necessary mounting hardware.
Installation is easy and tech support is available. Twin carb kits sell
for $119.95, and single carb kits go for $64.95. One of each and you’ve
got enough for a triple. Call Thunder Products at 320-597-2700 or visit
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