I bought and installed new jets stamped with the numbers on them. They are what matches the spec exactly.

For sure frank. I’ll give my own YouTube review Sent from my iPhone using Tapatalk

Hey @Ajmboy thanks. So here's an update on tis PITA! CDI was a complete failure and it did not do the trick. Valve lash was good, timing spot on. Carburetor is perfect and she runs great to half throttle and starts backfiring like hell. Regulator is on the way, i am stalking the stator, pick up and flywheel! Just about gone over everything else. Stay tuned. I was actually going to search the archives to see if anyone else had this problem.

Yes. That is it Sent from my iPhone using Tapatalk

They are definitely bad as* machines. I'm more of a utility quad rider but if you are a sport rider, this is a good machine to get.

Thank you, it is important to be heard and get more legal ATV miles. Mike

Thanks Ajmboy! been watching videos all morning on these bad as* machines! Just looking to see if there are,or has been any major issues with them. I have found that some have had problems with some crankshafts,but a Engine guy says it the operators fault ,not the machines.

@mikeexplorer we've shared this to our facebook and twitter pages.. 😎

Welcome to Quadcrazy @Sudsy Cant say you got me beat if mine is a lot cleaner then yours. Buy anyway post some pics and lets see that thang!

Frank Just 1 last thought, you using an (analog ohm meter) instead of digital 1 for the (pick-up coil and stator & voltage regulator) Engine Off tests. I know on most older and some newer Honda's, Kaw's, Suzuki's required a non digital meter for these types of test to get good solid reading measurement, due to the sensitivity of some of the digital meters. I'm Hoping the CDI box solves your problem, it will be interesting what your future posts will reveal for the fix. Good luck!

Without a factory service manual in front of me, I'm just throwing this as an idea to a possible cause? or it could be some other related safety switch inline the ignition circuit harness. Just curious if the your quad was equipped with some form of (ETC) Electronic Throttle Control switch, like a Polaris product would be equipped with. Or some form of 1? used by Suzuki. In the advent the throttle cable breaks or becomes stuck or out of adjustment the ETC kicks in, Grounding the CDI BOX out. I had this problem before on my 01 trailboss because the cable needed adjusted. normally it should of just killed the engine going from idle into "mid range" throttle. but the switch contacted ground intermittedly (causing backfiring) when it should of just killed the CDI box all together at mid range throttle if adjusted correctly. Knowing you already checked the , 1) In & Ex Valve clearances, 2)Spark Plug resistor cap (Rx Value), 3) Spark plug, even though new? got some out the box that were bad. Flywheel Key half sheared due to the back firing, Flywheel Magnets (magnetic poles become unstable to be not useable). Even if a ignition coil tested good, seen them also cut-out when accelerated due to a internal crack inside the field windings which you can or cannot see. The Stator plate and alternator windings for shorts? After the wiring harness being cooked, your lucky to have spark, depending how good of condition the CDI box and pick-up coil in the stator are? after the fire. Finding were the previous owner left off?, is real treat or sometimes a real headache.

Damm U still chasing that ghost ?? Id like to know what it is when u find it !!

Frank looked my cdi up in the manual. Doesn't look doable.

Sorry we had a lazy snowy day on the farm, just saw your reply Frank. I've read that the regulator could be the culprit with your symptoms. Output above 15.5 v can cause the cdi to loose it. I've just about got the front fender off the lowest millage machine. Shouldn't be much to get the piece out for you. Unfortunately I'd not be able to say it's for sure good.

I'll send you one of my cdi units to try if you like. Don't know if the KQ 300 is useful or not.

Yeah. I say carb because maybe a vacuum line in the carb has a small hole in it somewhere. I’ve had my Mojave’s and a few warriors that did this. Sent from my iPhone using Tapatalk

Carbon arcing with the spark plug maybe. KFZ has to have hit one of em. Checked rectifier output?

Well timing is spot on so its on too the next thing!! The valves and head look brand new. This is a tough one! Everything else tested good electrically. I may pull the flywheel and maybe replace it. It could possibly be a bad cdi but im going to hold off until the last minute before i pull the trigger on that.

Thank you @James Mason. I pretty much for the most part will always find the problem and to be honest I'm a little excited that its giving me a hard time. I think for the most part the quads i find are more straight forward repairs and find myself doing more cosmetic/body work. Don't get me wrong i love all that stuff but a real problem for a change is something good and i think keeps us all sharp learning about new problems, especially for the next guy. So we will see! A ton of very good reply's to this topic so a big shout out to our members that commented on this. Keep em coming. Always grateful!

Thanks @Dra O, definitely going to get to the bottom of this one. And yes i have checked the choke. Even if i put $1000 into it i can tell you i would still be way ahead. Its in perfect condition with a plow and winch. As of right now total money spent on parts is $65 for a harness and $20 on a carb kit. Oh and about 10 hours of shop time!!! Good luck on the new find. Hopefully it works out and you can snag it for a good low price. I happen to love those year bikes. Be sure to post pics if you do wind up getting it.

not going past half throttle? did ya check the, um, choke? what a project, man! those wires - good grief, that's literally freakin' neurosurgery right there - all hail to new harnesses!! that thing is freakin' SWEET lookin, frank - you'll get it running - a little here, a little there - and we'll all learn something in the process i'm going to look at a 1998 arctic cat 454 this saturday - talked about it before - I doubt it's salvageable and i'm not gonna get all crazy about it like the honda 250 - just looking - taking battery and plenty of tools - will post pictures soon

Give em hell bro [emoji1598] Sent from my iPhone using Tapatalk Give em hell bro [emoji1598] Sent from my iPhone using Tapatalk

It could very well be a timing issue. The kfx was thrown out of time due to stretched timing chains. Caused a back fire and stumbling idle. All the luck brother Sent from my iPhone using Tapatalk

Update: New harness is installed and carburetor rebuilt! I thought for sure this would solve the problem since the spark looked 10 times better. NOPE! The engine refuses to rev past half throttle. Carburetor is 100% good, i have a lot of backfiring as well but that was also going on before all this. Tested all components except the cdi and we all know why we can't test that little fucker, but everything else is well within spec. Now I've gone over the entire engine and nothing looks like its been taken apart in fact its all factory looking and like new but i am leaning toward the timing because the backfire issue or maybe a cam?? Pick up coil maybe ? But it tested good, the rpms coming up seem to throw it off. Flywheel/magnets???? I guess take a look at tye top end first and go from there. Stay tuned! FML......

Lol. Found a harness $65 bucks oem. Its on the way. Perfect condition. Canceled the other one. Also putting a new rebuild kit in the carburetor. The bowl gasket is not sitting in the grove correctly any more so i have a drip.

I hear ya. Motor runs great. I found a new harness at a good price so hopefully its a wrap with about $140 bucks. Its in new condition so we will see!!!!!

So !!!!! Pulled the carburetor off to clean it up. It was already clean and ready to go. Found a small fuel leak on the bowl due to to the seal on the bowl not fitting correctly. Ordered a new kit with the gaskets included. However I found worse, there are patched wires from what looks like a small fire. I picked apart the wires as best possible but it seems theres a short someplace within the harness. I had it running for a while but will not rev. So im going to dig deeper. Some people suck! The previous owner knew there was a fire and hid it pretty well.