Thunder PowerJet

$ 64.95$ 189.95

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.

Available in single, twin, or triple cylinder kits.


Thunder PowerJet offers:

  • More Power
  • Improved Fuel Efficiency
  • Easy Precision Jet Changes
  • Adjusts For Altitude and Temperature
  • Works on Snowmobiles, Motorcycles, ATV’s & other vehicles

Thunder 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.

Power Jets and Thunder PowerJet

Power Jets 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 counterclockwise for increased fuel flow and clockwise for less fuel. The Thunder PowerJet is nickel plated for corrosion resistance as well as great looks. The 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 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 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 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 PowerJet kit comes with everything you need for installation including an excellent installation and tuning manual. Technical support and information are 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.

Thunder PowerJet Manual

Best if used with Deep Well Float Bowl Nuts

SnowTech Magazine Technical Preview

Thunder PowerJet 
Quick-Adjust Fuel Delivery

     Do you have a carbureted sled? Are you sick of changing main jets in the carbs?  How would you like a quick-adjust fuel delivery system that not only lets you change the amount of fuel in seconds, but also gives you increased precision of the amount of fuel provided?
Anyone who knows carb tuning knows they have to select a main jet big enough to provide enough fuel for peak horsepower, peak torque, peak pipe temperature and peak engine temperature. This is one of the main drawbacks of a carbed fuel delivery system. By the time you get the main jet size big enough to cover the bases and keep the engine alive, you are over-fueling the low end and midrange. Pretty much anything below 3/4 to 1/2 throttle is going to be over-fueled. Enter the Thunder PowerJet. From the mind of fuel delivery master Lonn Peterson at Thunder Products Carburetion, this is a new twist on the good old power jet system. Where the old-style power jet would add a secondary fuel delivery system to your carburetor with a removable fixed orifice jet inside, the Thunder PowerJet gives you an adjustable needle and seat metering system instead of a fixed size jet. This gives you incredible precision and infinite adjustability, all done with the simple twist of a knob on top of the assembly. Rather than fiddle with changing main jets you simply twist the knob on each carb, which should take you maybe a couple of seconds.
This not only gives you the added capacity to delivery more fuel (great for big engines that suck a lot of fuel) but by virtue of reducing the main jet size (typically down to 75-80% of what you started with) the fuel delivery at all of the partial throttle settings is now better matched to the needs of the engine. This results in crisper acceleration, better throttle response and improved fuel economy. Your sled flat out will run better, faster and stronger. And it’s quick and easy.  Fuel distribution throughout the incoming air column is also improved by adding fuel through two sources instead of just one. Where the fuel from the main jet is coming up from the floor of the carburetor, the Thunder PowerJet is injecting the fuel right in the middle of the carb bore where the airspeed is the highest and the fuel signal is the strongest. This means better and more complete mixing of the fuel and air which provides more horsepower and torque at any temperature or altitude.  So, you install smaller main jets into your carbs and let the Thunder PowerJet come online at the higher throttle openings, supplying added fuel when the engine needs it. Start rich and work your way down, just like doing the main jets. When you get to your desired exhaust gas temps, plug color or piston wash you will be amazed at how quick and easy it is to keep your sled running crisp and clean with a simple twist. Be it between heat races, as the temperature changes or going up or down in elevation, the Thunder PowerJet gives you the ability to change the fuel delivery quick and easy. You have an adjustment range of 10 to 12 main jet sizes with precision external adjustment. The top of the knob is marked for index purposes so you can be sure each carb is adjusted the same.  The adjustment range of 10-12 main jet sizes is across about four and one-half rotations of the knob. This means you have incredible resolution and adjustability by simply adjusting the knob – one half rotation of the knob is (roughly) one main jet size, so a quarter turn is close to a half-jet size change. The precision is by design, and the adjustability is infinite. The applications for the Thunder PowerJet are many. Maybe you want precise quick-adjust jetting to compensate for changes in temperature or elevation. Maybe you want to clean up the fuel delivery on the low end and midrange and let the PowerJet fill the gap on the big end. Maybe you have a mod sled that needs more fuel than what big mains typically provide. Where the main jet affects fuel delivery across the entire throttle range, the Thunder Powerjet is adding fuel when the engine is pulling hard and needs it, typically above 1/2 to 3/4 throttle. Think of it as a power jet with an adjustable needle and seat and you start to realize the benefits and performance potential. This fits any and all carb sizes and styles, but you should install a deep well float bowl nut to give you the space to install the fitting into the bottom of the carb as well as give you the fuel needed to supply the power jet. This helps make sure both the main jet in the carb and the power jet have plenty of fuel to work with, even on that wide-open throttle high horsepower pulls across the lake or down the drag strip. The Thunder PowerJet is so helpful that every carbureted snowmobile should have this installed. The ability to adjust the fuel delivery, quickly, with added precision, is reason enough, but when combined with the improvement in power delivery from top to bottom and improved fuel economy it becomes a no-brainer. You could actually install it, set it and forget it, just like your plain old main jets, and still benefit from the improved performance of having more accurate fuel delivery across the board. But those who do pay attention to their exhaust gas temps, spark plug color and piston wash are going to benefit the most as they will be able to keep this edge all of the time, quicker and easier than ever before. You can get the Thunder PowerJet system for singles ($64.95), twins ($124.95) and triples ($189.95). You’ll also want to get the deep well float bowl nut for each carb as well, ranging from $9.95 to $24.95 each. Each kit comes complete with everything you need for installation and complete instructions for installation and adjustment, along with expert tech support. Contact Thunder Products Carburetion at 320-597- 2700 or visit


Additional information

Weight 1.1 lbs
Dimensions N/A

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  • Thunder PowerJet
  • Thunder PowerJet
  • Thunder PowerJet
  • Thunder PowerJet
  • Thunder PowerJet
  • Deep Well Float Bowl Nut

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