Need help getting 86 R to idle

[85Atc350x]

My R will not idle whatsoever, let off the gas and it dies, it loads up alot if you dont snap the throttle when your not riding it like when im warming it up. It is not modified whatsoever other than a new .25mm (.010) over honda piston an oldschool answer silencer that i just repacked and a UNI airfilter. It didnt idle before the rebuild either. I was running MC1 at 32:1 and it was loading up bad at when I would just start it cold and try and let it warm up so now im trying 40:1 and it still loads up, but not as bad, it wont foul a plug unless you just hold the throttle steady. My question is , what is stock settings for the pilot, clip etc. I havent opened it up yet, but I would think that stock settings should do. Also if anyone has any suggestions let me know. I have cleaned the air filter for starters and that hasnt helped.

Justin

[Mr. Richard]

justin, have you screwed the idle adjuster up a little?????
do you know that the choke is also the idle adjust screw it clockwise till it idles,,,,,,,,,,,,,,,how many turns is the air adjusting screw out from closed too????

[Ronjon851]

I've got an 85 and as far as I know the only difference is your's has a square slide in the carb and mine has a round slide.Both are 34mm so maybe this will work.Turn the AIR screw all the way in (clockwise)until it LIGHTLY seats,then back out 1/4 turn.that way it will at least start.Let it idle until the engine gets warmed up.That is if it will idle,Idle screw out about 1 7/8 to 2 turns out.Get it to idle and after it is warm then you can set the air screw correctly.With the choke off,turn air screw out (counterclockwise) until you get the max.RPM out of motor.Note how many turns out that you have.Then turn the screw in until it will just barely idle.Find the medium point of the two extremes and you should be fine.Your pilot jet is probably a 52.The air screw regulates how much air is allowed into the carb and by turning it in makes it run leaner.Here's a link about the whole carb tuneing theory.Read it a few times and you'll be a pro. http://justkdx.dirtrider.net/printcarbtuning.html Yeah it's for Kawasaki's but the whole carb is explained very easily.If you don't like that check out the website for Keihin.Peace

[Mr. Richard]

Your pilot jet is probably a 52.The air screw regulates how much air is allowed into the carb and by turning it in makes it run leaner.



86 runs a #42 pilot jet and screwing the air screw IN makes it richer,,,,, there is a little difference between carbs on 85 and 86's

[Ronjon851]

Yeah,what he said.Either way your stock pilot jet should be fine.Just play with the air screw and remember it's only effective from idle to 1/8 throttle.

[85Atc350x]

Yes I know that the choke is the idle adjust as well, I havent even bothered to look at it. To fiddle with the air screw dont I have to take the top off the carb, Im not sure I have not messed with this one yet and I dont need to mess anything up. It should have the stock #42 in it, the whole atc is stock for the most part, the motor was never into until I got it and the gaskets started leaking.


The main reason for my post was that, if I hold the throttle at what I think is idle and dont snap the throttle enough, I could ride about 2 minutes and it will foul the plug. It is loading up at an idle RPM so what could this be? Ill try the choke idle adjustment this weekend.

Justin

[Ronjon851]

The air screw is the little screw right on the bottom of where the airbox snorkle goes into the carb.there's a big screw (idle adjust0 and a little screw (air/gas).the hole inside of the air/gas screw determines how much air is drawn into the pilot jet.No you don't have to pull the cap off.All you will need is a slotted head screwdriver.Sound like you're running too rich.

[Mr. Richard]

on a flat slide carb there is only one screw on the side of the carb that is air screw,,,,, the pilot jet sucks gas not air ,,,, if your fouling plugs that quick your float level might be to high ,your oil ratio might be to rich ,,your air cleaner might be dirty,,

lets start from the begining,,,, clean and oil the air cleaner ,,mix gas at 32:1,,, drain tank and carb,,,, put fresh gas in,,,,,, turn gas on ,,if no gas is running out of the vent tubes move on,,, screw the idle adjust all the way down ,,, now open it up 4 turns,,, now screw the air screw in all the way ,,, open it up 2 full turns ,,, then start and warm it up,,, now readjust idle ,,,,, let us know what happens

[Tecate performance]

i thought 85 and 86 carbs were both roundslide

[Mr. Richard]

85 round slide 34mm
86 flat slide 34mm

[85Atc350x]

About 2 weeks ago i cleaned the air filter, flushed the tank and carb and changed from 32:1 to 40:1. I tried fiddling with it tonite. It seems to want to idle a bit more but still dies within a few seconds, after i ran it for a few seconds i took off and it was loading up alot until i blew it out in 4th. It is pretty cold here about 20 degrees so that might be a problem too. After I blew it out it seemed to run a little better , but it still died and didnt idle, Im gonna look at it again tomorrow.

Justin

[200x_Basket]

i would check the float / seat. it sounds like it is flooding into the motor.

[85Atc350x]

Thats next if this doesnt work, if it is the float, its probly just stuck i would hope and I wont have to spend anymore money.


Justin

[ronnjon851]

200x might have a point there.There's a problem with too much fuel flowing to the motor.Have you inspected the reed cage.maybe a reed is bad.This is also a suggestion but will not solve your problem,run a hotter plug in it.If you have a BR or B9es drop down to a B8es.I prefer a hotter plug in cold weather but remember not to run too hot of a plug as they are self cleaning.The plug must run in the 450-850 degree range.

[Mr. Richard]

if the float seat was bad you would have gas running out your vent tubes!!

[dunerash]

Im with ronnjonn could be reeds(frayed, cracked or warped) or a silencer that needs to be repacked

[85Atc350x]

I got it to idle by turning up the choke knob enough. The reeds looked fine to me when i had them out when I did the top end. Kasey you might have a point about gas running out if the float is bad. If i let it sit with the gas on for a while, not running gas will piss out onto the floor. Im running a br8es, i also have a b8es i was originally running and some br9es plugs for when it gets warmer out. I repacked the silencer a few weeks ago. I rode it today and it was running really good until my friend ran into me and bent the axle, but i straightened it anyways. Someone give me an idea on that float.

Justin

[Ronjon851]

The float is easy.Take the carb off,unscrew the four screws for the bottom of the float bowl.While you have the carb apart might as well clean/inspect it.the floats travel on a pin that has a metal tang with a spring attached to it.Turn the carb upside down.The top line of the floats should run parallel with the base of the carb.The floats are not rising up enough to allow the float needle to seal off the fuel.Therefore the excess amount of fuel is spilling out of the carb.Do this over a towel or a clean surface in case a small part drops out from the carb by accident.Hope this helps

[Ronjon851]

Almost forgot.A little trick that makes it easier to get the airbox snorkel onto the carb.Take it off and bring it inside with you and let it warm up for a night.It makes it a whole lot easier when it is warm and pliable.I was outside in 20 degree weather and that worked great

[85Atc350x]

Ill give it a whirl maybe next weekend. I also have to fix my 87 250x. It needs rear axle bearings bad, Im just waiting for the seals and o rings, damn service honda.

Justin

[Mr. Richard]

ok theres your problem!! your filling the crankcase up with gas when its setting ,so it has to get rid of it somehow and fouling a plug before it gets cleaned out,,,,,,

[85Atc350x]

Even if the gas is turned off i guess it will still flood it out, that sucks, Ill take it apart next weekend or something. Its sooo friggin cold out it sux to do anything.

Justin

[Ronjon851]

YEAH BUT IF IT SNOWS YOU'LL WISH YOU WERE OUT THERE RIDING AROUND IN IT.

[85Atc350x]

It runs fine when your riding it. It will load up a bit at idle, thats all. I rode it yesterday.

Justin