Main Jets for Scooters, ATVs, Karts, Buggies by MRP

JET KITS by MRP

Check www.MRP-SPEED.com for our full selection of jetting and jet kits.

MRP carries a full range of Carburator Jets, repair kits, and jet scooter tools.
Jets are an essential part of any mechanic tool department. If your store does not have a complete jet selection it will lag behind any many simple carburetor repairs will take days instead of hours. Carb Jets like roller weights or tires are something you should always have in stock.

Now you're probably asking what do they do? Well when you adjust a carb for racing or if you change a carb you need to tune the jet properly. To find the right main jet, start with a large jet and move down number by number till you find the right size. If you pull the choke at full gas (fatter mix) this will lead to a poorer output or lower rpm's, meaning you should change your jet to a smaller number. Gummy buildups in the exhaust opening, a darkened exhaust, burned spark plugs or improved motor performance with a partially closed fuel tap are other signs of a too large main jet. If you're upgrading to a larger carburetor then you will need a larger main jet. The main jet should increases 10% for every millimeter enlargement of the induction
diameter.

The Main Jet: Your main jet is too small when your motor runs better when the choke is pulled. Your spark plugs will usually look white and you motor will ping. In this case, simply increase the jet size till you find the right one.
To judge if you have the right size, your motor should run smoothly when at full throttle and your spark plugs should be brown in color.
When idling, the motor needs a different mix with less air for lower rpm's. When the throttle is almost closed there is a small low pressure area in the upper range of the throttle, which is not enough to activate fuel flow to circulate in the main jet. Instead, an increased vacuum in the lower part of the throttle activates circulation in the idle jet. This circulation can be regulated through the idle jet, the fuel mix or the air adjustment screw.

The most important aspect of a carburetor is it's size. The value of the carburetor size is based on the diameter of the induction port (for example, PHBG 19 = 19mm induction port diameter) Depending on how much the motor has been modified, a larger induction diameter guarantees a real power increase in higher rpm's, while a smaller carburetor diameter results in better acceleration.

To save valuable time we suggest always having a full selection of jets available for your most common carburetors and engines. If you sell JOG -- Minarelli based scooters then you should have a full stock of 70 to 110 size jets for GY6 100 to 170 depending on their application having these in stock will be extremely helpful.

Check www.MRP-SPEED.com for more information

Category:

Autos & Vehicles

Tags:

• Main
• Jets
• Carburators
• carb
• jetting
• tuning
• Scooters
• Scootering
• atv
• buggies
• buggy
• MRP
• Malossi
• Delorto
• Polini
• Racing
• NCY
• KT

[Noetzkahuna]

HOW MANY SIZE'S ???? !!!

[mikelovesbass09]

how many sizes above standard jet do you suggest i couldnt hear shit cause of the music man

[matthewmarrs123]

yes sometimes if it is not putting gas into the carb bowl like it should then the main jet is clogged.

[milkalait]

will a main jet effect ildling or take off

[scootergrisen]

Turn up the voice and turn down the music...

Hard to hear what he is talking about.