Fuel Screw

Can any of the ills be helped by the adjustment of the fuel screw?

My idle is somewhat erratic and I was wondering if there was anything I could do for now short of spending money on jet kits and exhausts.

What "ills" are you dealing with?

Pilot jetting and fuel screw adjustment will effect warm start issues...

with a restricted exhaust you seem to get the erratic idle - not sure why

my guess is the bike was never designed to be run that way????

both the xr650r and the klx450r seemed to not idle down properly when plugged up

this seems to just go away after letting it breath properly

http://www.thumpertalk.com/forum/sho...d.php?t=812250

seems I read there was some connection from the neutral switch in trany to the tps and ignition

if memory serves me right - it was to allow a higher idle when in gear than in neutral

I think this was to help eliminate some engine braking

I can't say I have noticed this feature?

engine breaking is not a big deal for me after riding xr 600 for years

the engine breaking is a problem for the guys coming off 2 strokes

Not sure how this relates to your variable idle speed - if at all???

One thing I noticed after removing the stock speedo and putting on the Vapor was that the idle never jumps around any more. Not sure why must be in the electrics somwhere.

With the neutral switch connected, bike in neutral, it causes the ignition timing to be slightly retarded which aids a smoother, slower idle. With the switch connected, the advanced timing tends to induce the dreaded hanging idle. If the TPS is set correctly, the neutral switch connectd and pilot/fuel screw is test and correct, the only other possibility is heat issues, like an over heated carb causing the fuel to excessively vaporize.

Assuming everything on your bikes is in proper order, do you notice it worse as the bike gets hotter?

I was having the high idle problem on my bike as well and it took a while to figure it out. What I found is disconnect your hot start cable at the lever and make sure it has enough slack to properly seat. To tight causes a lean condition. Also be sure the nut that holds the hot start plunger in is tight and not cross threaded. The other thing I found is that the carb boot clamps need to be super tightend or this will cause a lean condition as well. With the bike on the stand idleing spray carb cleaner on specific parts of the carb one at a time and eliminate air leaks. Air leaks will cause the hanging idle and are an easy fix.

Mine was doing the samething after uncorking the bike all of that stoped. A 165 main , 45 pilot and a KX450F needle on the fourth groove from the bottom. It only cost about 30.00 bucks. Do the air box modifacations. I did not do the fuel screw. The only modifacation there is to knock out the plug. I turned the fuel screw out 1.750 turns. Hope this helps. Happy trails

Mine was doing the samething after uncorking the bike all of that stoped. A 165 main , 45 pilot and a KX450F needle on the fourth groove from the bottom. It only cost about 30.00 bucks. Do the air box modifacations. I did not do the fuel screw. The only modifacation there is to knock out the plug. I turned the fuel screw out 1.750 turns. Hope this helps. Happy trails

Which needle spec did you use?

the kx 450 needle is NCVR kawi part# 16187-0214

the same needle from yamaha is part # 5TA-14916-vr-00 also a NCVR

the suzuki part # for NCVR is 13383-35G50

hope this helps you can search on google for "yamaha NCVR" and you will get the part #

also the parts listing will have several other needle #'s available from your dealer

This needle cost me $15. and the 165 main jet was $8.

it doesnt mater where you get your needle as all the Jap bikes use Keihin fcr carbs

it was better for me to order a Yamaha needle as its here in town but the Kawi dealer is 1 hr away

KLX450JUNKIE are you still running the stock "pea-shooter" exhaust tip

you said you did the airbox mod but never mentioned the exhaust

I was curious as I was wondering if I went back to the stock tip for a "stealth ride" if the

jetting would be workable - right now I have a replica of the PMB tip

also how did you like adjusting the stock fuel screw - a bit of a pain eh!!

I thought about removing the starter to set it - but stuck it out instead

Haven't had to adjust it since - so am glad I never wasted $ on an aftermarket screw

No, I made a 2.0" insert. The needle was the NCVR as stated above. What a difference it makes. I made the adjustment when I did the other modifications. So it wasn't to bad. I'm at sea level to 3500 feet. Happy Trails.

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