1984 Honda ATC250R question

[xomatosis]

1. I need to know where the Main Jet, Pilot Jet, and Air / Pilot Screw are on the carb. I see one large screw (guessing its the main jet) and below it to the left is a smaller screw (guessing its the Air / Pilot Screw). I am not sure though, looking for some carb guidence please.

I just purchased this last weekend, bike runs pretty good imo but doesn't idle at all. When I got it home it had no air filter in the air box, I put one in 2 days ago (UNI). Also, it was running very very rich so I did a few plug chops and leaned it up a bit. The air filter box has holes drilled in it, that can't be right?

[RodKnockRacing]

If you take the nut off the bottom of the float bowl and the carb and look thats your main jet. If you take the float bowl off the pilot jet is along side the main jet and if you take it out it has tiny holes in it. The air fuel screw is the one angled down tword the float bowl on the outside of the carb. The idle screw is the big screw on the outside off the carb with the spring. hope this helps i have a hard time explaining its easier for me to show someone.

[xomatosis]

If you take the nut off the bottom of the float bowl and the carb and look thats your main jet. If you take the float bowl off the pilot jet is along side the main jet and if you take it out it has tiny holes in it. The air fuel screw is the one angled down tword the float bowl on the outside of the carb. The idle screw is the big screw on the outside off the carb with the spring. hope this helps i have a hard time explaining its easier for me to show someone.

I'm a complete noob to this, but I thank you for your info. So the big screw is the idle screw... That is the screw I turn about 2 1/2 times counter cloakwise to lean the air/fuel mix. lol, I really don't know if that was the right thing to do.

I am very leary of taking the carb apart...

[xomatosis]

Also, where is the best place to get parts for these 250r bikes? Besides Ebay or Craigslist.

[Yamaha_Rules69]

No, the big screw on the side of the carb that you can turn by finger is the idle screw. There is no specification for this screw, you just start the motor, and turn it --- in would make a faster idle, out you make it slower. You may have to adjust the idle screw again once the motor is warmed up, as it will idle a little higher. The other screw on the outside (standard screwdriver) is to adjust the air/fuel ratio. Check the intake manifold for cracks, as it is a common problem with these machines. As stated above, the main jet and pilot jet are inside the carb, and the carb must be removed and taken apart to gain access to them. To me, I would try to adjust the idle screw first, if that dosnt help, adjust the throttle cable, and if that dosnt help, take the carb apart and clean the pilot jet. It uses a smaller standard screwdriver to get it out. Good luck!

[Rainer]

People like to drill holes in their airbox lid to increase air flow if you want to go faster and some people that race em' don't use the air box lid at all

[MonroeMike]

http://72.52.143.80/~trikes/atc250r_...vicemanual.pdf

[xomatosis]

No, the big screw on the side of the carb that you can turn by finger is the idle screw. There is no specification for this screw, you just start the motor, and turn it --- in would make a faster idle, out you make it slower. You may have to adjust the idle screw again once the motor is warmed up, as it will idle a little higher. The other screw on the outside (standard screwdriver) is to adjust the air/fuel ratio. Check the intake manifold for cracks, as it is a common problem with these machines. As stated above, the main jet and pilot jet are inside the carb, and the carb must be removed and taken apart to gain access to them. To me, I would try to adjust the idle screw first, if that dosnt help, adjust the throttle cable, and if that dosnt help, take the carb apart and clean the pilot jet. It uses a smaller standard screwdriver to get it out. Good luck!

the big screw on the outside with the spring around it is the idle and the small screw on the outside but is inside the carb wall adjust the air/fuel ratio?

Intake manifold, just rubb my fingers around it and feel for a hole/puncture or do I need to take this off and look?

Thanks Monroe Mike, I have already downloaded that manuel but for someone dumb like myself just reading that manuel doesn't explain everything. Especially the carb, the pictures don't even help lol

Thanks for all and any help, you guys are so good at this. I understand that trying to explain to a newbie can get very frustrating. I will do my best to understand.

[xomatosis]

found a picture, to bad we can't use a pointer on it lol

There is one screw kinda in the middle, large, which is idle ?

and another smaller one down to the left , which is the air/fuel ?

What tools will I need to tear down the carberator and clean jets if needed etc?

[xomatosis]

Well today I got the bike to idle but the idle screw is screwed in so far that the spring looks like its gonna pop off lol, I also unscrewed the air/fuel screw a few turns cause the bike eventually died out. Now it seems it could idle until out of gas but the RPMS maybe a bit high. How do I test the RPMs at idle?

[RideRed250R]

okay so heres the deal the big screw you see sets the idle,
the little one is the mixture screw, it should be about 2 turns out from all the way in. I like my 2 strokes to be alittle rich at idle. because hell they dont see idle much.

inside that bowl, will be a jet that is sticking out, it goes into the bowl, that is the main jet, there will be a little tube under the float that will contain the pilot, the 3 jet is the needle and clip, that sets how much gas comes through the main if you lower the clip, more fuel is let into the cylinder, if you raise the clip it lowers the needle and lessens the gas intake.

sounds like your carb needs a thorough cleaning, your pilot jet is to lean or plugged up or both. it should idle without a problem

[RideRed250R]

you need a flat head screw driver (skinny) and i believe a 5 or 6mm to unscrew the main jet.

[xomatosis]

Where can I purchase different sized jets for my carb? Also, I have read up on factory jet sizes and also bought a carb kit and ALL have different main jet sizes

from the book I down loaded here the size is 158 :O
from the book I ordered off ebay is 148 for my alttitude
the main Jet in the carb kit is 130

???

Air filter is UNI but stock exhaust, lower then sea lvl or just at sea lvl with stock carb...

[xomatosis]

Also for the 84' R , the carb is a Keihin #5C9? Venturi dia?? 27? 30?

Where can I find this info? Cause I need to order some Main Jets...