88 kx80 runs like crap

[sblt500r]

starts right up, runs good sitting there. when you take off the bottom end is okay. the midrage it falls on its face, it breaks up till it can get to the top end then it will clear up.

carb has stock jets, the needle was at the top notch so i put it 3rd from the top, 2nd is stock. new plug, stock exhaust, reeds look good.

only thing i can thin off now is the oil is mixed wrong. it has pure smoke coming out the exhaust when you rev it. i didn't mix it, i think it was told it has champs oil mixed at 32:1. also the pipe is a bit lose in the head.

so what did i miss?

[Banshee]

I would start by changing out that oil no sense racking your brain when it could be something you didn't touch. Are the jets cleaned out?

[sblt500r]

yup, i cleaned the carb. the pilot jet was just sitting there! blew all the jets out with air. the chrome on the slide is gone in spots, think that would cause it to run shitty? it idles nice, so its not sucking air.

[sblt500r]

heres another thing, its missing the o-ring and washer that goes on the air/fuel screw. would that suck air down the threads without the o ring and washer?

[FPMXer]

Yes air can get in there and thats what the O ring is for the washer is for the spring to rest against. I would run the oil mix at 40:1 and there should be less smoke and still plenty of lube for the bottom end.

[Big Dave]

If your carb slide and barrel are worn real bad you wouldn’t get it to idle correctly. I would tighten up the head pipe then replace the missing o-ring & washer on the air screw. You could be pulling air causing it to run erratic at different rpm.

[95hondaxr250]

Hi I am having problems with my 1986 kawasaki kx500 too I can not get my carb set right. The idle surges after you rev it up. When you let off the gas it does not just go back to idle. It lopes around for a second. I do not think that the air and idle scews are set right. I am looking to find the stock screw settings. I have finally got the bike so it starts within a couple of kicks and runs with out the choke on. When I close up the air screw it seems to get better but not perfect. Something is off. Any help would be great.

[elliot-wright]

i put 15ml of premix o every 5l of petrol in my kx85 would have fault there wouldnt be an difference. have u tried taking the carb of and totally cleaning it out with wd40. have u tried starting the bike up with evrythink nomall taking the the air filter out and sprayin wd40 down it whilst giving the bike high revs i get the sae sort of problem often and that seems to solv it. also try turning on the petro and underneath the carb will be a bolt at the botom of the carb undo it till its out and let the petrol run through for 10 seconds den turn of the fuel and put the bolt bake in. check that the,anafold ataching the reeds to the carb is done up tightly and no air is getting through that maniold as i ahd that problem last week.

[sblt500r]

this is a bit old! i did get it running good. i jetted it richer and fixed everything. went from a 155 to a 165 main jet. runs like a champ now. been beating the crap out of it ever since!! lol

[MX86]

how far is the air screw out?