WOW... im frustrated.... again...

[NMills]

Ok... i know we've been thru this several times about my 450 carb... I've taken it out... re did all the holes... start it up and let it run... when i first start it... runs great at start up... idles fine for a couple minutes and then the idle starts to climb a bit... and then after it's warmed up the idle stays high... i've backed out the idle adjustment... so it should be either idleing or just falling on it's face... i've had the mixture screw anywhere from 2.5 turns out to 5... I dropped the pilot from a 52 to a 50... needles been on the 2 and 3 notch... the last thing i'm thinking is the choke is being a pain... or does someone else have a thought??? also as a note... the machine could not run better.. she seems to run and go much better then before... it's just the actual idle that's driving me nuts...

[CJM]

Leave it alone if it runs fine. I have the same thing going on with the EX carb. Start it up it idles good, fully warmed up it idles much higher. Nothing bad has come of it.

[punk rock kiel]

well then im glad i aint the only one that has this little issue.

[NMills]

I may end up leaving it alone... but i'd still like to know why it idles soo high and theres nothing i can do to get it down... does everyones 450r carbs idle high??

[matts27]

Check for a vacuum leak around the carb boot. Spray some brake parts cleaner or carb cleaner and you'll find the leak quick. Use the nozzle extension to help pinpoint the problem. That's what it sounds like when you can't control the idle speed. Matt

[NMills]

been there... sprayed it... checked.... listened... let it run for a few... spray it again... and can't find anything...

[matts27]

Pilot screw looks good, needle straight? Have you tried new needles, pilot and main? Float isn't hanging up and overflowing? Just throwing out issues I've had.

[NMills]

both jets are new... needle looks fine... pilot screw looked fine...

[killer454]

i dont know but could it be in the throttle cable adjustment,holding the slide up in the carb.

[supertrooper90]

I had the problem with my 450r carb. the cable was routed incorrectly and caused the throttle to be pulled up a little causing an nonadjustable high idle.

[tri5ron]

Is your throttle cable adjusted properly?
do you have the correct freeplay in your throttle lever?
(3 to 8 mm)
Does your throttle cable have any unusual bends or kinks in it ?

[NMills]

plenty of play in the throttle.. no bends kinks or anything... can't seems to figure this out... and it's driving me nuts...

[tri5ron]

ok, just a thought here, and I can't really remember if it applied to my 450r carb,...
but it's worth taking a look at.

Taking this straight out of the factory manual for a 400ex carb...
(sorry, I don't have a factory manual for the 450r carb),...

quote-

"Make sure that the piston and butterfly throttle valves are fully closed." "Make sure the clearance between the link arm shaft, and the throttle link arm is .01 - .03 mm (0.004 - 0.012)

Adjust synchronization by opening or closing the slot in the throttle link arm."

-unquote

[NMills]

Hmm... sounds like something to check... does anyone have pics of that???

[tri5ron]

give me a minute or two, I'll see what I can do.
Here ya go...

http://i111.photobucket.com/albums/n148/tri5ron/03%20400ex/IMG_3288.jpg


Remember to Keep in mind,
this is from a FACTORY 400EX MANUAL,....
for a 400EX CARBURETOR.

[NMills]

Actually... i may not need it.. i'm looking at a service manual for the 450r.... hopein that will give me an idea...

[tri5ron]

let us know if the 450R manual states the same thing or something different.

Post up a pic of it from the 450R manual , as I have done from the 400EX manual.

[NMills]

Heres what it shows... sorry i had to use my print screen buttom as i can not figure out how to copy from Adobe...

[tri5ron]

great, so they are the same. now go check you carb to see if the butterfly, and slide are fully closing TOGETHER, (syncronized), and let us know what you find.