I have an '03 yfs200. the only mods are an fmf power core 2 silencer and a set of boyesen dual stage reeds.

I cannot get this effin' thing to idle. I've tried the adjuster on the piston for the carb, the adjuster on the throttle itself and an adjustment on the air/fuel. I just replaced the reeds(originally boyesen when I purchased the bike) with the same dual stage reeds from boyesen. the carb was jetted to match the reeds by a yamaha tech.

The idle problem originally occurred last year when I serviced the carb and wondered what the knob on the top of the piston assembly did. and the rest is history. the bike will run and does so smoothly, starts fine, runs great when it gets warm. but I have to feather the throttle to keep it running and it's rather frustrating.
lesson learned...if it isn't broken, don't adjust it!

During my adventures inspecting the throttle cable and throttle assembly(on the bars), I found that there is a  bad bushing that aligns the throttle and the whole thing can wiggle around from where you put your thumb to the linkage inside that pulls the cable(could this be why?

I tested the carb switch that's in this assembly for continuity and found it to be functioning properly(as far as a connection goes, if it is a potentiometer I'd need to break out the ohmmeter).

any help is appreciated  

it's a balancing act when i have little more time this evening i'll explain it further, yo have to balance the thumb throttle on the carb tors unit and the air/fuel mixture.

and sometimes you have to adjust it at the throttle itself as well.

will explain more later,

heading back to finish up a raptor upgrade before the customer gets here.  

also did you rebleed the oil injector pump after removing the carb?
take the right side cover off and there'll be a little screw you take out, it will gravity bleed just make sure all of the air bubbles are out.  

Where? on the carb? or do you mean trace the line into the crank?  

and by asking that question I do mean that I have not done so, had no idea. I'm new to working on this(usually I work on sleds) so there are some procedures I am totally unaware of.  

ok the oil injector pump is under the right side cover. the plastic piece on the front right.
when you take the plastic cover off you'll see it, it's square aluminum with the line from the oil tank going into it, and the line feeding the carb coming out of it.
there's a small screw on it just off center of the pump.
remove the screw and let it gravity bleed until there are no more air bubbles coming out of it. the air bubbles and oil will come out of the screw hole.
then after you have done this of course put the screw back in... take the oil line off the carb, take the spark wire off,  you don't want it to run while you do this.
kick it over until the oil comes out of the line with no bubbles. probably a good 15-20 kicks to get the air out of the line.
be sure to put the oil line back on.

The carb air/fuel adjustment is so close in, mine are jetted and exhaust severely modified for horsepower,
and aktive race reeds
but still they set about 1 to 1.5 turns out from all the way in.
the key is small adjustments.

it sounds like you have yours close, if it runs but dies while trying to idle then you are super close.
try turning the air/fuel mixture screw out a very tiny amount though. (if you turn it out it idles higher.
so turn just until it doesn't mAke it idle higher and out of control, then add just a small amount of idle.

if no luck there ptu the air/fuel mixture screw back to where you had it and turn the idle screw down, and start adjusting the fuel/air mixture out a little at a time.
like i said it's a balancing act. (and so stinking hard to explain.)
I find myself going nuts wanting to sit down with it  just for 5 minutes.

the blaster is a pain to tune the carb.  they are so picky on the tuning but once you have it right it works like a champ!!

you can get it to where it doesn't want to idle and if you turn the air screw too much then it idles high and out of control.

hard to explain, but if it's idling high you need to actually turn the fuel air mixture screw in a little, giving it more fuel and adjust the throttle screw in small increments.
it's a real pain, i can tune it in about 5 minutes sitting in front of it, but i have done it so many times.

really your best bet is to disable the oil injector and mix your fuel with the oil yourself.
the injector pump clogs very easily and there's no warning, you just end up burning the engine up.
and not to mention the carburetor will adjust SO much easier. you can plug off the hoses on the pump, but you have to unplug the idler sensor, and unplug the tank sensor, and remove the bulb from the oil light.

you can buy a pump block off plate for these too.
that way you can remove the plastic drive gear inside as well, these are bad about breaking and you end up with hard plastic in the crank case.

I own two of the blasters and am completely happy with them. absolutely strong 200cc engines and with a 6 speed gear box you get some nice top end. not to mention the super light 324 pound atv.

the injectors work well when they are working but you'll never know they clogged up until it's too late.


I ran boyeson superstock reeds on mine but iam running the Aktive carbon race reeds now, man what a difference!!!
and i have my exhaust custom modified. so it breathes easy.( a little loud though but man it sounds good and runs like a demon)
have mine stroked and bored out too.

Ray  

WELL, I AM A LITTLE CONFUSED. NO MATTER WHAT I'VE DONE AS FAR AS ADJUSTING IT'S NEVER COME CLOSE TO IDLING. AIR/FUEL, OR THE CARB ADJUSTMENTS HAVE ALL PRODUCED THE SAME RESULT. NOTHING. IT DOESN'T EVEN SOUND LIKE IT WANTS TO IDLE. YOU SAID I SOUND LIKE IT'S CLOSE BUT IN THE 10 HOURS OF TRYING TO ADJUST IT NOTHING HAS WORKED. COULD THIS BE CAUSED BY NOT BLEEDING THE OIL?

i'M FAMILIAR WITH THE COMMON PROBLEM AS FAR AS THE AUGER TYPE OIL PUMP, BUT I'D RATHER LET IT GO FOR NOW. i SAW A THREAD WHEN I FIRST VISITED THE FORUM ABOUT THE CT SONIC BIG BORE KIT, AND SINCE HAVE PURCHASED IT. THE WHOLE SHEBANG, CARB, CYLINDER, EXHAUST. I HOPE THAT IT PRODUCES THE RESULTS THAT I'M LOOKING FOR.

bUT THERE IS A RIDEABILITY PROBLEM, I'M 6'2" AND 190 POUNDS. i MAKE THIS THING LOOK LIKE A POWER WHEELS TOY. i'M PLANNING A WIDENING KIT(4-7") AND AN EXTENDED SWINGARM AND WIDER REAR AXLE TO MATCH THE FRONT.


BACK TO THE MATTER AT HAND, THERE SEEMS TO BE A CONSIDERABLE AMOUNT OF PLAY IN THE THROTTLE CABLE ITSELF. ABOUT 1/8 THROTTLE IS WHERE I START TO GET RESISTANCE FROM THE SPRING IN THE PISTON. ONCE I GET THE RESISTANCE IS WHEN I GET THE RPM'S UP. AND I CANNOT CONTROL IT SO I HAVE TO FEATHER IT AND PULSE IT JUST TO KEEP IT GOING. MAYBE I SHOULD PICK UP A NEW CABLE?. OR IS THIS DUE TO THE OIL ISSUE?   i REITERATE THE FACT THAT I CAN DISASSEMBLE AND REASSEMBLE BUT THE PROCEDURES ARE WHAT I LACK.

ONTO THE OIL. YOU ARE TALKING ABOUT THE PUMP THAT SEEMS TO BE IN THE BOTTOM END? AND ON THE CRANK SIDE OF THE MACHINE?   i WAS HESITANT TO OPEN IT UP BECAUSE IT SEEMS THAT THAT IS THE COVER FOR THE GEARBOX, AND I CAN'T HAVE OIL ALL OVER MY DRIVEWAY. SO YOU ARE SAYING THAT THIS IS NOT GOING TO DO SO OR SHOULD I REMOVE MY GAS TANK AND THROW IT ON IT'S SIDE? WHICH KINDA DEFEATS THE GRAVITY. i DO KNOW IT IS GETTING OIL TO THE CRANK AS I REMOVED THE CYLINDER YESTERDAY TO CHECK. ALSO MY EXHAUST IS VERY SMOKEY AND IT SEEMS TO BE RUNNING HOTTER THAN USUAL, BUT YESTERDAY WAS THE FIRST TIME IVE BEEN ON IT IN A MONTH OR SO, AND I MAY JUST BE PARANOID.  I'LL DEFINITELY BE BLEEDING THE OIL ASAP.

AND 324 SEEMS HEAVY TO ME I CAN PICK UP THE FRONT END AND PUT IT ON MY TAILGATE AND THEN LIFT THE BACK END BY THE GRABBAR AND GET IT IN MY TRUCK IN LESS THAN A MINUTE ON MY LONESOME. WHICH IS WHY I REALLY LIKE THIS MACHINE. i'VE GOT 2 SO FAR ONE OF THEM I'M HALF INTO WITH A FRIEND WHO LOVES RIDING BUT COULDN'T AFFORD TO GET ONE ON HIS OWN. QUICK LITTLE MACHINES AND 6 SPEEDS OF FURY!  

SORRY FOR THE CAPS LOCK I'M AT WORK IN A PARTS DEPARTMENT AND THE KEYBOARD HAS TO STAY ON CAPS LOCK SO THEY REMOVED THE CAPS KEY.  

AND WHERE THE HELL IS THE IDLE SCREW?  THE ONE I HAVE BEEN DEALING WITH IS ON THE LOWER RIGHT HAND SIDE OF THE CARB ON THE LEFT OF THE MACHINE.  

no the idle screw is on the "torsion" unit,  (the aluminum carb control on top of the carb, the thing with the idle sensor switch inside.)
the only screw on the carb is the air/fuel mixture screw.
yamaha didn't put a idle screw on the carb, they put a thumb screw on the throttle tors unit on top of the carb. so you should only have one screw on the carb for air/fuel mixture, unless someone has changed the carb.
remove your seat and you'll see the thumb screw. it will be about 9/16 in diameter and will have a slot for a flat screw driver.

also with it having slack in the cable, up by the thumb throttle unit on the handle bars where the cable goes into the thumb throttle casing, there is a black rubber boot where the cable goes in,  pull that back and you'll find a cable adjustment there, loosen the nut and turn the cable out to tighten then re-tighten the nut to lock it once you have all the slack out.
there shouldn't be any slack in the cable, it should have positive pull all the way through it.

Are anywhere near the chattanooga tennessee area?
i'd love to look at it. i could have it set for ya in no time.  as i said it's a pain to explain how to set it.

the big bore kit should really turn the power out on your blaster.
but with the big bore kit you'll need to eventually block off the oil injector and mix the oil yourself.
the oil injection pump is really nice to have but it is not adjustable, so it will not put out anymore oil than it does from the factory. meaning you may not have an adequate amount of oil for the upgrade.

iam 170lbs and mine drags me around like iam a flea.
the 324lb blaster is the lightest sport atv made in it's cc class. you'd be surprized how fast you can make the blaster go.  
the suggested upgrades are a big bore kit, a 1 up chain and sprocket kit, boyeson or aktive carbon race reeds, boost bottle, you don't have to have a stroker crank but they are nice.
a good "d" slide carb 30mm or better.

back on the subject at hand, if you are close to my area bring it by i'd be more than happy to set the carb for ya and show you how to yourself.
it is a pain to tune. but once you learn how then it makes a little more sense.
 
also bring it by with the big bore kit and i'll put it together for ya.


have you turned your front wheels around yet?
it will widen the stance on the atv. also if you haven't already ditch those factory rear tires. they are left overs from the balloon tire era and cause you to lose stability.  get you a set of hole shot tires or good mud/snow rear tires. you'll be surprized at how stable it becomes.

also a lowering kit will give it a wider stance and make it easier to corner and for it not to stand up on ya.

if you are not in the area maybe try a phone call so i can hear the engine run and try to talk you through tuning the carb.  shoot me a pm and we can try this if you like.

oh yeah what size was the carb rejetted to?

Ray  

i tried reversing my front tires some time ago for the very reason you mentioned, but i had a problem with the valve stems clearing the tie rods? i'll try it again to be sure, but does this sound familiar to you?  

yes it's common on the disk brake models.
go down to your local parts store and by some shorter valve stems. simple and easy to replace. and a really cheap purchase.
but it fixes the issue with them hitting the tie rod ends.  

i have a 93 YFS200 blaster and i think the oil injection pump isn't working. i was told that most people just take their oil pumps out and mix their own gas. i would like  to do this but i need to know what the mix is for my quad. i think it might be 32:1 but i am not sure.  

you are correct, the fuel mixture is 32:1