air screw????

Got questions? We got answers....
Post Reply
danbra
Member
Posts: 22
Joined: 03:54 am Jun 09 2007
Country:
Location: pepperell, ma

air screw????

Post by danbra »

hello everyone!!! I'm new to this site and new to the dirt bike worlld!!!
coming from road bike I don't know much about carb adjustment, I just installed a fmf woods pipe on my bike and removed the snorkel from the air box , I know I must rejet it, but I don't want to do it jut yet until I do more power wise on my bike. I tested a little bit this afternoon and it seemed like it was sputtering a tiny bit a 1/4 throtle, so I turned my air screw a 1/4 turn clock wise and it looks like it worked a little better, I don't know how many turns the screw was set at from my dealer since I bought new . is there anything else I can do to improve trhotle reponse or rejetting is the only option and if it is how hard is it to rejetit my self??
what should I be looking to do? thanks in advance Dan


ps: the bike is a 2005 kdx 220r bought brand new as a leftover
i
2005 kdx 220r
bone stock...
...until I found this forum!!!!!
User avatar
Colorado Mike
Gold Member
Gold Member
Posts: 1921
Joined: 11:42 am Feb 25 2005
Country:
Location: Colorado

Post by Colorado Mike »

Welcome Dan!

The jetting isn't that tough to do compared to a street bike because you only have one carb to deal with, and on the KDX, you can get the thing off the bike without major disassembly. There are a bunch of posts on this site on this topic, check the stickies. Basically, assuming the bike is properly broken in, you need to get it to operating temperature (like ride it good and hard for 10 minutes) then you're ready to start doing plug chops. You need a supply of spark plugs and a stretch of open area where you can hold it wide open in 4th or 5th gear for 20 seconds or so. Get to that spot on your regular plug, change to a new one, and take off getting up to wide open in 4th or 5th quick as you can. run the 20 seconds, and pull in the clutch, kill the motor and let off the throttle all at once. Get to a stop and pull that plug out put in the old one and ride back to your truck. cut the threads off the old plug to see the dark ring at the base of the insulator, plenty of pics on here to see what it ought to llok like. you adjust your main from there until it's right, then work your way down to the needle, then the pilot jet.

Personally I just jet the pilot to start well, and call it good, but I'm lazy.

The next step in your evolution will be to get the RB carb mod, and don't even waste your time getting that without having him do the head too. 220's need a bunch more compression. Also, swap out that grenade Kawi calls a piston with a wiseco while you've got the head off . The 220's crack the pistons pretty often.

Have fun, and read up! :supz:
Mike

Life's tough, it's even tougher if you're stupid.
'04 KDX220
User avatar
Jeb
Gold Member
Gold Member
Posts: 1894
Joined: 08:01 pm Jul 14 2006
Country:
Location: Cincinnati / Northern Kentucky

Post by Jeb »

Welcome, Dan!

I second everything Mike said.

If Colorado Mike's recommendations on how to get the jetting right seem like some work, it is - but know that the results are well worth. You'll read about simpler methods on other sites but they typically only show relative changes - the wide-open-throttle chop Mike describes works and shows quantitative info that you can use. I know this to be the case through personal experience! I've wasted time going about it wrongly.

The Wiseco piston is a smart move . . .

so are the RB mods for more of that 2-stroke yee-haw!!

Enjoy . . .
"No farmer ever plowed a field by turning it over in his mind" -George E. Woodbury

CLICK FOR PICS!
User avatar
canyncarvr
Gold Member
Gold Member
Posts: 6943
Joined: 01:07 pm Nov 05 2004
Country: US
Location: The Mythical State of Jefferson

Post by canyncarvr »

Suspension is as good a go-fast part of things as is the engine.

For starters, set the shock sag..and then set the shock clickers to suit.

The compression clickers on the OEM forks do not have a huge impact..but might as well bracket them (change to either side of what seems to work just to make sure you're in the right spot).

A fork oil change will help. The OEM junk is ....junk. Mobil1 ATF works for that.

Don't forget to have fun riding the thing!!

Welcome!
Last edited by canyncarvr on 11:53 pm Jun 20 2007, edited 1 time in total.

Consider the source
Using a perceived level of knowledge to boost my self worth.
Non impediti ratione cogitationis

bike profile: !clicky!
User avatar
2001kdx
Supporting Member I
Supporting Member I
Posts: 1522
Joined: 08:36 am Sep 23 2006
Country:
Location: Town of Montgomery, NY

Post by 2001kdx »

Any auto-tranny fluid would work as fork oil, correct?
User avatar
canyncarvr
Gold Member
Gold Member
Posts: 6943
Joined: 01:07 pm Nov 05 2004
Country: US
Location: The Mythical State of Jefferson

Post by canyncarvr »

I don't know that is or is not true.

I do know that Jeremy Wilkey (MX-Tech) recommended Mobil1 ATF for at-home fork oil changes. It works fine for me (whatever that's worth, which is about as close to nada as zero on the Kelvin scale).


Seeing as some fork oils run in the $50/qt. range, I'll stick with the rec of someone whose job it is to know such things.

Consider the source
Using a perceived level of knowledge to boost my self worth.
Non impediti ratione cogitationis

bike profile: !clicky!
Post Reply