Just another JETTING thread.... Help?

[pods_BMOC]

Can someone please help me on my quad here,... i cant find it right

-Wiseco 416
-11:1 compression
-Port and polish
-stock head
-e-series slip on
-Minnesota




Help would be wonderfull:)

[hypersnyper6947]

you have to tell us what is in it now and how it runs through the whole throttle

we need pilot jet, needle position, and main jet

[pods_BMOC]

I have 155 main and 55 pilot,.. it will not even start,.. just pop and then nothing, needle in middle position,..

[Newrider08]

try a 42 or 45 pilot, I would go with a 42. If you are getting enough fire to make it pop then its the fuel so it must be WAYYYY too rich.

Just throw a 42 pilot and if that is too lean do a 45

after it starts you can worry about making sure the main is good but if your that rich on the pilot circuit the thing will not start it will just flood out

[pods_BMOC]

Ok, i will tune down the pilot,.. also will a 416 11:1 give me much of a power increase over stock? I also had port and polish,..

[Newrider08]

with the mods you have listed you will DEFINITELY feel a difference, I am actually wanting to do the same exact setup on mine later this year.

Have you had it started at all since the rebuild?

[pods_BMOC]

No, not yet,.. just put the kit in and finished a few nights ago, And waiting on my FMF carb jetting kit.

O any idea what notch my needle should be in?

[Newrider08]

factory is 3rd from the top, I would go with that first and fine tune it later, the key is to get it started first

you might check your spark and make sure all your wires are connected but I would say if you are getting popping and smoke out your exhaust then the fire is fine you just have to get your air/fuel mixture right

[Newrider08]

this is a great place to learn about jetting a keihin carb, it is the duncan racing site and its is very helpful when I have questions.

http://www.duncanracing.com/techfaq/Tech_keihin-carburetion-jetting.phtml

[Newrider08]

PILOT JET: The pilot jet is a medium size (¾-1") brass jet located inside the float bowl next to the needle jet/main jet location. The pilot jet meters the fuel required for engine starting, idling and the initial throttle opening 0-1/8.

A lean pilot jet setting will cause your engine to surge at very low RPM’s, bog or cut-out when the throttle is opened quickly and have trouble idling down.

A rich pilot setting will result in hard starting, plug fouling at low RPM’s, sputtering as the throttle is cracked opened.

The pilot jet is not difficult to set. With proper air screw adjustment and a close initial setting from your engine tuner, fine-tuning should be painless. Once set the pilot jet is not terribly sensitive. You should only be required to adjust the setting when confronted with large weather changes or altitude swings of over 2000 ft.

If adjusting the pilot jet gives inconsistent feed back, or does unexplainable things. Check and clean out the pilot/slow speed system thoroughly with contact cleaner and blow out with compressed air.

Pilot jet sizes are numbered in the following pattern; #42, #45, #48, #50, #52, #55, #58, #60 etc. repeating the pattern. Sizes available on most models are from #35 to #80.







MAIN JET: The main jet affects the jetting in the upper quarter of the throttle position. Coming into play at ¾ throttle on through to full open throttle. Even though most people relate the main jet to their carburetor in general. The main jet is only responsible for the last ¼ of the jetting. The main jet does not effect the jetting for starting and idling. It plays no part on low RPM or mid RPM jetting either. The main jet is very important to your machines overall tuning, but should never be over emphasized at the expense of needle tuning or other facets of your carburetion tuning.

When the main jet is Lean the engine will experience detonation or "pinging". Exhaust note will be of a higher, tinier type note. Engine will over heat easy and can be down on horsepower. A moderately lean main jet can cause engine seizures. A severely lean main jet can cause the engine to burn a piston (whole in top).

When the main jet is Rich the engine will be a bit flat or lazy at ¾ to full throttle, giving off a flat, dead sounding exhaust note. When the main jet is severely rich the engine will sputter in the high RPM’s and have a lot of trouble making power up top.

The safest way to get the main jet setting as near correct as possible is to richen the main jet setting up until the engine begins to lose power and not rev to as high of RPM as before. On a single cylinder machine this will signal that the jetting is beginning to get rich. Depending on your riding application you can lean it down a bit from there or leave it for conditions requiring extra fuel (desert racing, long high speed runs, etc.)

As a general rule, richen the jetting up as long as the engine likes it and continues to run just as well or better than the smaller size main jet previously installed. When the engine no longer continues to improve its performance you will know you have gone to far.

Main jets are offered from #90 to #230. Starting at #90, sizing cycles like the following #90, #92, #95, #98, #100, #102, #105, #108, #110, #112, etc…. up thru #200, #205, #210, #215, #220, #230.

[honda400ex2003]

mine is in my sig. steve

[hypersnyper6947]

i have 48 pilot needle on the 3rd notch from the top, and a 178 main in my 450 carb

[pods_BMOC]

Thanks guys, i will try this out tomorrow night and let ya know how it goes,

Thanks again,

Ethan

[DirtMonkey]

http://www.exriders.com/vbb/showthread.php?s=&threadid=344906&perpage=13&pagenumber=1

[pods_BMOC]

Here it is,..


170 main
38 pilot
needle 2 1/2 turns out
airbox cover on
snorkle on
e-series slip on

runs AMAZING!!!! Holy POWER! my 3rd gear is outstanding!!!! i compare power to a buds stock 450r,.... He said so himself!