Mini Quad Dial-A-Jet Application

Tuning automatic mini quads can be challenging at the best of times. The air-cooled models are even more difficult with holed pistons when there is the slightest hint of leanness. These engines are based on auto scooter engines and experience many high load conditions because of the nature of the auto drive trains, not to mention the environment they operate in.

Small capacity engines such as these require high compression ratio's to create good torque and here lies the problem. The race courses filled with jumps, tight turns and sandy sections keep these engines working in the high load range of the auto drive train. One minute your little quad is flying and the next it standing still with a hole in the piston and an engine full of molten aluminum pieces.

By fitting Dial-A-Jets to our auto mini quads, we are able to solve all carburation problems and eliminate load related engine failures. We are also able to create more torque and acceleration, without stopping the engine from having good top-end rev.

Most of our circuit machines use 24mm flat slide Mikuni carburetors. An adapter is machined for the mounting of the Dial-A-jet. This is then attached to the carb, which is setup in the mill for machining. There are other easier ways of mounting Dial-A-Jets, but we have chosen to use this method of mounting because it is more suitable for this carburetor and the UNI pod airfilter that is mounted directly on the carb.

Once all the machining is finished, the Dial-A-Jet is fitted to make sure all alignment is correct and that the attachment thread is accurate.

The carb is then removed from the mill and cleaned. A small section of Dial-A-Jet blue fuel hose is cut 10mm long and pushed onto the fuel delivery tube (brass jet tube). This helps to create a strong seal between the fuel delivery tube and the carb bell mouth.

Beside looking trick, this is one of the most important modifications you can do to your engine. We have now added an additional fuel circuit to the carb will create more horse power and torque and at the same time created a safety feature against detonation.

We have used this setup for years with great results on all in-house build auto race quads and that amounts to many championships.

In this view you can clearly see the brass fuel delivery tube that extends to the high pressure point in the carb throat. The high pressure point is in the center of the carb bore. For this fitment, it is necessary to use a 0.055" XL fuel delivery tube.

Finnish fitted with a snorkel kit to keep dirt and very very small animals out. The carb can now be jetted externally, thanks to the Dial-A-Jet. The main jet has been dropped two to four sizes and it is ready to go.

If you have gone four sizes down on the main jet, you will probably need to richen the needle one position. Altering jetting is now as easy as removing the snorkel cap, slackening of the brass delivery tube 1/2 to 3/4 turns and rotating the air metering dial. Smaller hole size for richer and larger hole size for leaner. The dial has five different air jet sizes to choose from.

Big Power and No Fuss.