86 ATC 250r WON'T IDLE

[dabody69]

So I just got a very nice 250r the other day, took it out for its first ride and when i went to pull the choke up half of the black plastic knob crumbled in my hand, I then noticed even after it was warmed up the thing would not idle, I went to look for the idle screw and starting messing with what later i figured out was probably the air screw, first question is how many turns out should the air screw be set at? 2nd question is, is the choke knob itself the actual idle screw, I have never seen this before, my buddy has an 85 and his carb is more of what im used to.. I turned the choke knob all the way in as if I was turning an idle screw clockwise and it did absolutely nothing, I though for sure I would hear the motor start to rev but it did nothing no matter where I turned it to. Can someone please advise to WTH is going on, I really need to fix this issue asap, Does someone make a quality carb kit for the 86..?

[oscarmayer]

In my sig is a link to factory service manuals


Sent from my iPhone using Tapatalk

[dabody69]

In my sig is a link to factory service manuals


Sent from my iPhone using Tapatalk

Thanks but i can't see them or download them, it says there is a problem with the server.. anyway, not sure how the manual is going to help me other than tell me where the air screw is set from the factory, Help!! Anyone!! Can i really be the only guy with this problem??!!

[onformula1]

You should be able to download Oscar Mayer's manuals, I just checked it. (Do you have a pop-up killer of some type)

http://www.oscarmayer.net/atc/manuals/honda/atc250r_85-86_servicemanual.pdf

Stock air screw is 2 1/4 turns OUT, I always seem to be at 1 1/2 turns out on trikes/bikes I build.

adjust the air screw then adjust the idle. Or adjust to zero idle and enjoy!, Race trikes/bikes don't idle, many don't even have chokes.

Yes, the choke knob is also the idle adjustment, pretty cool, great carb.

Stock main jet- 145
Stock slow jet- 42
Stock needle clip- 3rd groove from the top
Stock float height- 16mm

[yaegerb]

Air screw needs to be between 1-2 turns out from seated. Have you cleaned the carb thoroughly? May have a block in the pilot circuit.

[Racer-X]

Most carbs are.....tighten it all the way to the right then back it off to the left 1 and a half turns. That should be a close baseline to the factory setting. Then tweak it from there if you have too.

[bkm]

I have found that with most 30 year old carbs, especially the PJ series like your carb, is the slide wears and internally the carb becomes "loose" making tuning a friggen nightmare, not to mention the internal passages that are impossible to fully clean after decades of junk building up in them. I would suggest a newer bigger pwk carb to allow for future mods or a genuine kiehin 36mm pj replacement carb. The idle/choke knob is close to $40 new and then you still have a 30 year old carb.