YAJQ (Yet Another Jetting Question)

[HowellTRX]

Ok, so here's my scenario. I just put a FMF Q4 on with a Uni filter and a jetted to a 152 with a 40 pilot. I am 10 miles in from the ocean so I am basically at sea level. When I start it I seem to have a little hesitation now when I blip the throttle. It may just be me not letting it warm up before I jump to conclusions but what do you guys think? Any suggestions?

Also, I am running it with the stock airbox lid and snorkel still on. Should I remove them? Could I be airflow restricted now?

Thanks for the help guys!!!!

[honda400ex2003]

sounds close to me imo. 2.5 turns out on the f/a screw would be close with the 40. that will probably help it out a bit. steve

[JOHNDOE83]

hesitation is a lean condition.

I would say 80% of people here really dont know how to jet.

here are some FACTS about jetting and plug reading.

http://www.exriders.com/vbb/showthread.php?s=&threadid=441780&highlight=plug

[togup]

Originally posted by JOHNDOE83
hesitation is a lean condition.

I would say 80% of people here really dont know how to jet.

here are some FACTS about jetting and plug reading.

http://www.exriders.com/vbb/showthread.php?s=&threadid=441780&highlight=plug


could you elaborate "hesitation/ sputtering" they sound the same to me ive got a jetting issue as well and this info could help

[HowellTRX]

Thnx for the input guys. I originally didn't touch the A/F screw due to what FMF recommends at sea level. I'll investigate more this week.

[honda400ex2003]

what did they recommend? i didnt get any recommendation with my q4. :( lol make sure you warm it up fully before doing any sort of changes to it. 3 turns out from lightly seated may help out a bit better. steve

[HowellTRX]

Originally posted by honda400ex2003
what did they recommend? i didnt get any recommendation with my q4. :( lol make sure you warm it up fully before doing any sort of changes to it. 3 turns out from lightly seated may help out a bit better. steve

Hey Steve. I used the recommendations right from FMF's jetting center website. Being that there are so many variables that get thrown into the mix they can't guarantee the same will work for every machine but I still took their advise since they made the pipe :)

http://www.fmfracing.com/RiderSupport/JettingCenter

[honda400ex2003]

i would have to jet mine down to have optimum performance with my q4 after tuning it with my t4. it is quite a difference actually but you dont notice till you ride on both within 10 minutes of each other. lol steve

[JOHNDOE83]

Originally posted by togup
could you elaborate "hesitation/ sputtering" they sound the same to me ive got a jetting issue as well and this info could help

if your unsure which one its doing, go richer on the needle or main jet till it gets better or worse, then youll find out which one its doing.

its trial and error, alot of testing, alot of back and fourth.

anyone can give you a ballpark estimate to make it run better, but only you can tell where its best at.

if you follow my link, use the go big method, start at the pilot, then needle, then main jet.

do a actual plug chop in the end to see where its at, and you should be very close.

[f4iracer]

go to 3 turns out on the a/f screw. People on here keep saying that the screw is all the way out at 2 1/2 but it's not.

I've got a slip on/uni air filter and i'm running a 40 pilot with a 152 main jet. My needle is a dynojet needle on the 3rd clip setting.

I would go get yourself an adjustable needle asap and put it on the 3rd clip setting.

[honda400ex2003]

Originally posted by f4iracer
go to 3 turns out on the a/f screw. People on here keep saying that the screw is all the way out at 2 1/2 but it's not.

I've got a slip on/uni air filter and i'm running a 40 pilot with a 152 main jet. My needle is a dynojet needle on the 3rd clip setting.

I would go get yourself an adjustable needle asap and put it on the 3rd clip setting.

x2 i have ran mine at 3.5 turns out for yrs. The dj instructions actually say to go out to 3.5 with the 38 main and an exhaust. any bigger pilot can be brought down by around .5 turns to .75 turns in. so if you have a 42 pilot you can be from 2-2.75 turns out imo. that is my logic for suggesting on the f/a. steve