What is jetting?
- Thread starter chumley1/17/96
- Start date
It changing the size of the part in the carb that controls how much fuel is mixed with the air. Very important on a 2'atroke.You have three thinks that control your fuel flow. The air screw that controls your IDE.The pilot jet that controls your mid range. The main jet that controls top or wide open throttle . Anything that you do to a motor that will increase air flow will call for rejeting.
After mods like putting a pipe on, airbox lid removed, boring/porting your engine. Anything thats gonna affect you gas/air flow..
i'd be reading some stickied threads and using the search button extensively before you attempt, lean jetting can cause damage very quickly
Jetting is finding the correct main jet to use inside your carb so your engine runs great. The wrong jetting can lead to a burned up top-end.
You probably know that an engine must have the correct mixture of air, fuel and spark to run properly. Air and fuel are the variables that change the most. They're also the easiest to adjust, if you need to, by rejetting.
So if you change something on your motor that alters either of these variables.....like installing a new pipe, removing airbox lid, etc....then you need to determine which main jet size is now needed.
Both the new aftermarket pipe and/or airbox removal examples from above will allow more airflow. So to get the air & fuel mixture back into balance, you know you'll need a larger main jet for your carb to allow more fuel to flow. Jetting, in this case, would be the process of finding which main jet size will give you optimal engine perfomance.
There are two more variables you'll need to think about:
Temperature = changes in temperature will change the density of air. So if your quad ran great in the summer and it runs like chit now, you'll likely need to increase the main jet a size or two for winter
Elevation = change in elevation will effect air flow, again because of density. The higher up you are, the thinner the air is. Thinner air means more flow. The rule of thumb is you go up one main jet size for every 2000 ft of elevation.
Good luck!
You probably know that an engine must have the correct mixture of air, fuel and spark to run properly. Air and fuel are the variables that change the most. They're also the easiest to adjust, if you need to, by rejetting.
So if you change something on your motor that alters either of these variables.....like installing a new pipe, removing airbox lid, etc....then you need to determine which main jet size is now needed.
Both the new aftermarket pipe and/or airbox removal examples from above will allow more airflow. So to get the air & fuel mixture back into balance, you know you'll need a larger main jet for your carb to allow more fuel to flow. Jetting, in this case, would be the process of finding which main jet size will give you optimal engine perfomance.
There are two more variables you'll need to think about:
Temperature = changes in temperature will change the density of air. So if your quad ran great in the summer and it runs like chit now, you'll likely need to increase the main jet a size or two for winter
Elevation = change in elevation will effect air flow, again because of density. The higher up you are, the thinner the air is. Thinner air means more flow. The rule of thumb is you go up one main jet size for every 2000 ft of elevation.
Good luck!
Okay,what kind of kit would you recommend? I put an fmf powercore2 on it.
And another question,when i pull my clutch in now it sounds like im giving alot of gas,and i aint,what might the problem be?
And another question,when i pull my clutch in now it sounds like im giving alot of gas,and i aint,what might the problem be?
Blaner
Your Friendly South African Ambassador
perhaps your cables are too tight up by the handle bars or something, try re-routing them. No one here has mentioned the role of the needle in a carb, it also controls your midrange!
