i have a 300EX and i put a whitebros e-series silencer on it, along with no airbox. when i did this i didn't know about jetting. when i took the quad into the honda shop to get some maintanence done, they said that the jetting is fine, but it doesn't seem to have the power increase that it should, and the pipe gets really hot. i think im running lean, the problem is that i've never adjusted jetting before, and am not sure what to do. if ne body could describe in detail (where everything is, along with what to do) how to adjust the jetting so it wont be running lean, that would be great. thanx.

 

One could write a book on jetting. There are some articles around on it, so I will try to scare one up.

I would say PARK YOUR BIKE UNTIL YOU GET IT PROPERLY JETTED! With the mods, your bike is running LEAN, and you can BURN DOWN YOUR ENGINE! Add to that the fact that Honda jets lean at the factory, to meet environmental requirements, and you are in big trouble!

 

yea there lieing when they told u its jetted fine

http://www.yellowdogracing.com/techstuff.htm

 

i just jetted my friends 300ex that has a DG pipe and K&N. what you have to do is take off you plastics and gas tank to get acces to your carberator, then you loosen the clamps that hold the carb onto the engine and airbox. pull out the carb. turn it upside down and you will see a large plug at the bottom, take it out and your looking directly at the main jet. then all you do is unscrew that jet put your new 1 in.

then you should take the plate off the top of the carb and you will see a small arm and a rod that connects the arm to the slide. get a small phillips screwdriver and unscrew the plate the connects the arm to the slide the you should just be able to pull the rod and plate out of the carb and the jet needle will fall out also. look at the top of the needle and you will see a bunch of notches and a clip. to richen the jetting move the clip down on the notches to the very bottom or second to bottom spot and screw that all bak together.

oya im not sure what size main jet you will need, we tried my old 52main jet in my friends and it was a little to rich. also adjust the fuel/airscrew on the left hand side of the carb rite on the outside. [ in = lean, out= rich] if you run out of adjustment on the fuel/airscrew the you will need to go up a size or 2 on the pilot jet wich is next to the main jet in the float bowl

 

dang, i didn't realize jetting took so much work. i really hate takin the plastic off the 300ex, its such a pain. luckily we rn't going riding for almost a month, so i have time to not be lazy and get it done. does anybody know the stock main size? can i increase just the main and be fine? it idles just fine, its when it runs that it gets hot and it starts acting weird.

 

To be safe you should plug check at every stage of the throttle, 1/4 - 1/2 - 3/4 - Full. This way you can make sure you get your jetting dead on so you won't be running lean and you can get the most power out of your bike.
Jetting, $2.50 a jet, and a hour of your time. . .
Top end rebuild, $300.00 and a week of sitting on the couch. . . I'd take the first one. [img]i/expressions/face-icon-small-smile.gif[/img]

 

its really not that hard to do if you know what you are doing, it took me about 30 minutes to do my quad but after about 15 minutes of riding after that the rod that connects the slide to the arm come unscrewed and the only reason i got home was the accelerator pump given me a squirt of fuel when i punched it [it was a long ride back in second though] so remember to put some threadlocker on those 2 screws.