1991 kdx200 engine problems!!!!

hi i have a 1991 kdx 200 i recently picked up from my dads house. it used to run fine but since ive gotten it back it hasnt ran right. it smokes like a @#%$ and doesnt idle. i installed a brand new carb with no effect, tried all different kinds of jets to no avail, cleaned the pipe and silencer and changed the plug. nothing seems to make it run any better. it has no response to air/fuel mix screw adjustments or idle screw adjustments. the only thing i did with some noticeable change was i took off the choke completely(which created a massive vacuum leak) and it ran a lot better... i have hit a troubleshooting brick wall and NEED HELP! :busted:

Take off the exhaust and look at the piston/ring. If they are seized, that can cause your problem. If the are ok, check for transmission oil getting past the crank seal by keeping an eye on oil level at window to see if it drops. Could be coil/ignition/plug cap or stator also. You may have to ck all of these. Good luck.

thanks, i bought a fresh top end but havent put it in yet. i know its not seized because the bike does run, but not very well. i also recently replaced the crankshaft seal on the flywheel side. it was leaking before and the bike ran ok when it was leaking. i also was thinking it had to do with the ignition circut.. is there a way to test the components with a multimeter to see if theyre all ok? i really appreciate all the help

check your pm's. Just sent you one!

thanx. it said in the maual to check the coil with an ohmeter. i got a good reading on the secondary side but not the primary side. it read 0 ohms. so do i need to replace the coil?

does anyone have any other suggestions???

thanx. it said in the maual to check the coil with an ohmeter. i got a good reading on the secondary side but not the primary side. it read 0 ohms. so do i need to replace the coil?

doesnt sound like an ignition issue. what kind of meter are you using? the primary will be so close to 0 ohms that a lower quality meter or an analog meter will read 0. if you make a huge vacuum leak and it runs better then it is almost certainly a fuel air ratio problem. are you sure the float isnt stuck open? is the top end toast? do a comp test. do the reeds exist, and are they in good shape? what do you mean by new carb? no offense but are you sure you installed the seal correctly?

These bikes chew power valves , maybe thier stuck wide open , check compression, float in carb , re build your old carb and try that if still not getting anywhere

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