carb tuning help

[redemn93]

hi guys. i just picked up a 85 200x with a 200cc lifan motor. first off, i love this thing. so much fun. its my first own ATV/ATC of any kind. I road friends bikes as a kid but never had my own.

its got an aftermarket stainless header pipe from the original honda motor that fits the lifan perfectly. it is larger than stock. ill get the ID when i get home. its only got a tiny little 4" muffler on it. that part will change soon. also has no air box and a small k&n cone filter mounted right on the carb. i need to get a prefilter for it if one exists. starts right up but idle seems low and will stall until it warms up. ill put my tiny tach on it and adjust idle to whatever i find out is correct.

i finally got to go for a quick ride around the block yesterday. drives great except lets say you're cruising in 3rd gear and then go WOT. hesitates for a moment and then takes off pretty good. powerband doesnt really seem to flatten out much on the top end. then again, i dont know what it should feel like for a baseline. the previous owner said he never messed with the jetting so i expect it to be lean.

the tiny muffler has to go. sounds cool and all but way too loud. what do you guys recommend for a muffler? i need to keep costs low. stock, dented, rusted mufflers are going for $70-90. seems outrageous for what it is. was hoping to find something a little cheaper.

this weekend i plan to rebuild the front caliper and get the front brake on. next weekend ill rebuild the front forks if i have time. depends on this storm and where it ends up. once everything is all good mechanically i want to strip it and paint the frame. maybe 4-6 months from now. thanks for any help or advise.

[yaegerb]

It depends on your throttle position when it burbles or stalls. If your throttle position is 1/3-3/4 when it stalls then I would raise the clip 1 notch on the needle. if it is cutting out 3/4-WOT then your main jet is to large. Take it down a 1 size.

[freewheeler]

It would help to know which carb you have. Buy several different jet sizes now, save time later.

[redemn93]

it only stalls idling. idle seems really low to me though. need to get a tach on it to see.

if im cruising lets say 1/4 throttle or so in 3rd gear and then go right to WOT it'll hesitate for 1-2 sec then take off. if i lay into it slowly, its smooth. i've only really ridden it that one time.

ill try to see what carb is on it tonight and get a pic of the plug. i wont be able to pull it off and see whats in it till probably sunday.

[yaegerb]

Turn your idle screw in to raise your idle, then raise your needle clip 1 notch

[redemn93]

ill give it shot this weekend. thanks guys.

anyone know where or have a stock or any other cheap muffler/arrestor that would work laying around?

[redemn93]

so i got the idle set right. doesnt stall so damn easily now. raised the clip one notch and now it goes WOT throttle as soon as i start it. throttle mechanism is fine inside. what did i do wrong?

[yaegerb]

Your slide is 180 degrees out. Take cap off, pull slide out, spin 180 and put it back in. The slide should settle all the way to the bottom of the carb.

[redemn93]

i verified it when initially reassembling. pulled it off again and its right. any other ideas? i think im going to pull the carb and go through it anyway. pulled the throttle tube today as it wasnt returning at all. bars are nasty underneath. sanded everything to bare metal. put a shot of enamel paint on it. hopefully after that and cleaning carb ill have a returning throttle too. this bike needs some work but mostly all labor with minimal part really needed.

[yaegerb]

Only way it shoots to the moon when you start it is if the slide is out 180 or the throttle cable is stuck open or your idle is very high

[redemn93]

then i must be backwards on the slide. ill check again tomorrow. idle was perfect before move the clip up a notch. just to verify, raising the clip on the needle one notch will lean it out right? this is my first time playing with a 4 stroke carb. i first went down a notch to richen the mixture and the hesitation got worse. stalls when you try a quick rev from idle. initial position was 2nd notch from the top.

thank you for your help. you've been quick to reply.

[yaegerb]

No problem, yes, raising the clip leans out your needle circuit. You have three circuits on your carb.
1. Pilot circuit; 0-1/4 throttle
2. Needle circuit; 1/4-3/4 throttle
3. Main; 3/4-wide open throttle

Most people confuse needle circuit with the main and end up messing with their main jet when in reality their needle clip was wrong or their needle taper was incorrect.

[redemn93]

gotcha. thanks. ill try it this weekend. weekdays are a wash for me.