Can someone explain to what is going on with my bike. This winter I have take done a good overhall on my machine bearings and such, nothing to the engine except cleaned the carbs they full of crap. I have out it all back together and it is missing, spitting out the carbs and spometimes backfires(not Often). It does this at low rpms and it will idle fine but when you rev it up it misses and bogs. The first thing i thought i messed something up in the carbs so i have taken them back off 3 times i know they are ok. I put stronger springs on the choke cables and have good fire. Also adjusted pilot screws to 3 turns and 1 shims under the needles. My bike has worked well for a very long time with no all these issues and i dont what changed. I have some mods a napa snorkle that extend outside bike, Nyroc muffler mod, offset key and a Kunytec module are the main mods. One thing i just noticed if i block the snorkles airflow to almost half it works well at least on the bottom and mid range, i am not sure what it would do on the top end. Does anyone have any ideas for me i getting frustrated and i dont know hy it wont run well it seems as if nothing has changed. The last thinhg i did was to remove the engine brake actuator it would stop running all the tme and diid the light mod but it worked poorly before that any help?????

----------------

 

Blocking the intake airflow makes your quad run better tells me that your carburetion is lean.
Revving up makes you bogging and missing also says that it is lean.
Set the choke lever to about 1/2 way or more and see how the quad runs. If it runs better with the choke on, that means it is certainly lean. Let's do that first and go from there.

 

I try the choke and it did seem to smooth it out, it only seems bad at below 1/4 throttle and if give it gas quick it bogs
Jeff

 

when was the last time you set the vavles

 

I just did it and then rechecked them, i just ordered jets i will give that a try I think it makes sense i have a 2" snorkle pipe and Nyroc mod muffler with stock jets
Thanks Jeff

 

OK, you have a lean condition and it is lean at 1/4 throttle.
Changing the main jet may not help you much in this condition. What you need to do is to install richer needle jets which control the carburetion from 1/4 to about 1/2 throttle opening (low to midrange). Read your spark plugs and find out which cylinder is leaner/richer and work accordingly if you really want to fine tune the carburetion.

 

Any suggestions on the needles, where do do i get this and what size do i try. this is new territory for me
Thanks Jeff

 

Jeff,
Kehin makes several sizes of jet needles for your carb. If you remove them from your carbs, you will see a fine stamping on the jet needles that's composed of 4 alphanumerics, something like N4JK (this is something I just made up as an example - it's not what's written on your needle jet). You need to find out what it says from each carb, front and rear. Then, either contact Kehin or competent dealer mechanic and ask what might be the next richer one is. Usually, "later" the last alphabet it is, richer it is. So, N4JL is the next richer one than N4JK. In your case, I would install the needle jet whatever in the rear in the front, because usually the front needle jet is leaner than the rear on Kawi v-twin quads.