What Else Do I Do ?.

[MADMICK]

85 KDX200,JUST PERCHESED EXELENT CONDITION,BUT WONT GO,HAVE TOW STARTED IT ONCE ONLY,RAN SHOCKING ONLY HAD ABOUT I/3 THROTTLE ,WOULD NOT IDLE,SMOKED LIKE A TRAIN,HAVE GOT NEW PLUG,STRIPPED/CLEANED CARBY 3 TIMES,CHECKED EXHAUST 4 BLOCKAGE,RETIMED IT ,POLLISHED MAGNETTO AND STATORS,HAVE HEAPS OF SPARK ALSO GETTING FUEL BUT ******* WONT GO,SHOULDNT BE THE COMPRESSION AS IVE HAD IT RUNNING ONCE,IF THE TIMING STATORS WERE STUFFED THEN I WOULDNT GET GOOD SPARK WHEN I SPIN THE MAGNETTO OVER WITH A DRILL WOULD I ?,ALSO GET SPARK KICKING IT OVER WITH PLUG OUT ..HELP

 

[Dragonfly]

this may sound silly but do you have fresh gas in there. I had that problem once when I let my quad sit for a year then tried to run it on same gas......I did'nt know. I towed it for 5 mins trying to get it started. Grandpa said get fresh gas in there so I went and got fresh gas and fired off like a champ.

 

[Johnnyboy]

I would definetly get new gas and some good 2stroke oil. Check timing by removing flywheel cover on the left side of the engine and look for a mark on the bottom side. The pointer and the mark should line up exactly. Check your air filter!! If you recently cleaned it then remove it and try to start without it. If it's never been cleaned then clean and oil it. Check your reed vavles, if they are cracked or broken then they will definetly need replacing. Put in a B9ES spark plug. If none of this is fixing it then you have a jetting problem, I'd help you on that but I dont remember what mine are. If you get it running good then keep it. Early KDX's are rediculously reliable with very little maintenance.

 

[MADMICK]

bike has new fuel and good quality 2 stroke oil,have removed air box,has got new reed valves fitted,carby is spotless,when i got the bike the magnetto had been removed,so cleaned up stators,retimed it[2 timing markes at aprox 9 oclock] when looking at the magnetto.towed it and it fired up pretty well straight away,tho would not idle or rev.kinda sounded like the exhaust was blocked,removed exhaust [fine] checked timming [fine] good spark on kicking it over.towed it again got nothing ,didnt even fire once,removed plug still got spark,plug wet with fuel so shouldnt be the carby,tho stripped carby down again[fine].
i guess its gotta be electrical,but im getting good spark when i kick it over,have pulled the reed valves out a couple of times as they were fitted before i got it,but they are tight seals and can only be fitted one way,DONT KNOW as a rule there is not much that i cant get running
but buggerd if i can start this b*****d,apreciate your help guys MICK.

 

[Fred T]

You need 3 things to run. 1. Fuel, 2. Spark. 3. Compression. One of those are your problem...maybe it's compression because you've covered everything else. Take the top end apart and check it or at least do a compression check.

 

[derekk87]

Did you remember to clean the airfilter and make sure theres nothing in the airboot, i can tell that my bike doesnt run as well when my filter is only moderately dirty.

 

[woodsy]

Hi MM: What Fred said is 100% correct - however, ALL this stuff has to happen at the correct time! Here is how I would proceed if I were in your shoes:
1. do an ohm check at the plug terminal (unscrew the terminal and replace it with a known good one if you have an extra)! Spec check all electrics. Remove kill wire from system! Static time it! Out of time - check flywheel key! Try to start it!
2. Do a compression check - under 125 checked at WOT kicked thru 6 times plan on redoing the topend!
3. Remove pipe and air filter - try it.
4. Look thru exhaust port and check/test KIPS (if applicable) and examine piston/rings for smudging.
5. Check ports for obvious grinding (if this model is non-kips - maybe it has been over ported changing the port timing!).
6. Remove tank, airbox,carb, reed assembly. Roll motor to top dead center and evac crankcase (blow it out with air to remove an water/bad gas that has gathered - did this once and found out that the bike had been submerged and kept pulling water thru the transfers!)
7. Remove plug, put 1 teaspoon of fuel/oil mix direcltyinto plug hole. replace NEW plug, kick it over - bike should burn off fuel!
8. Dont run? Remove left side cover/drain tranny oil and pressure test for bad crank seals or base gasket. You could plug off motor and blow cigarette smoke in - sounds crazy but it works!).
9. remove top end and visually inspect ports/cylinder/piston.
Keep at it - you will get there!
Woodsy

 

[bj davis]

you might think i'm off my rocker,but you say your getting spark when you check it. years ago my bike just stopped running. in checking things out, i had spark, fuel, it was timed, and i had compression. what i eventually found was that when i pulled the plug and checked it, i had lots of spark, but when the plug wire was put back in its original position on top of the plug, the wire was shorting out to the frame and i had no spark. i guess when the wire was pulled and twisted while checking for spark, the wire was pulled away from the frame, eliminating the short. but putting everything back in its original position, the wire was again touching the frame. all this to say make sure there is a spark at the plug when installed in the engine. Good Luck!!