Hi guys and gals! I am a new member and am happy to have found this forum. I hope that it can be helpful. I just purchased, used, my machine and am experiencing problems. The engine is missing with increased revs with increased throttle. At idle and slowing increasing the throtle to mid range, it runs great. The carb is clean and is adjusted correctly and the vales are set according to what was indicated on the instructions. .005 for intake and .010 for exaust. I took it to an ATV shop and the owner said it needed a new CDI as it might be, and the key word is might, the rev limiter built into the CDI. I have never seen a CDI go bad and only one fuction of that CDI would go off without other parts of the CDI going bad. Perhaps someone else here has experienced the same thing. Could it be a clip fell off the needle valve assembly in the carb? Is there something else going on.

 

Is it common for a CDI (rev limiter) to go bad or is this a stator problem. I checked the spark on the plug as I reved the engine and it appeared constant but at that increased rpm it would be impossible to see a difference. Where is the pickup coil on the ATV. Is that now part of the CDI?

 

As a follow up: I disconnected the voltage regulator completely after starting engine. It ran fine until mid range and higher and again exhibited the same symtoms. I did this at the advice of a service tech to eliminate the voltage regulator. Does this narrow this problem down to the CDI and eliminated the magneto/stator and voltage regulator?

 

Has anyone use RegulatorRectifier.com for parts?

 

Did I mention that this machine has 148 miles on it and when I bought it, it had 110 miles on it. It is hardly broke in but this problem persists. Now don't all join in at once and underwhelm me.....

 

Maybe I can be of some assistance.

I dont know a lot about the electrical on these atv's, but I have a suzuki quadrunner 250 that I just rebuilt. The engine and transmission is identical to that in your arctic cat, except yours is the larger bore/stroke 300.

After I got mine together, I had it running great, except it had a miss at certain rpm's. It was always in the higher RPM's and it never missed just revving it, but when really on the throttle in 3rd-5th gears it was really noticeable. The battery was weak. It would actually start the atv pretty good, but it was weak for sure. So, I thought instead of chasing electrical issues, Id try a battery first since I had to buy one anyways. The thing starts right up now and hasnt missed any at all. Runs much better.

So, my advice for you right now is to double check your battery. Maybe put a good charge on it overnight and take it out as soon as you get the charger off of it to see if its any better. My battery would start the fourwheeler, but it was just weak enough that it couldnt fire like it needed to at higher rpm. I was very happy to see that had fixed my issue.

Hopefully that is some help to you. Keep us (well, me at least) updated!

 

Thank you for your reply. I will do that and let you know what I found out...jim

 

Ever get it fixed?

 

Yes, It was a bad CDI.....

 

Had the same problem with mine, the CDI unit was the culprit. There is truth tot he battery thing as well. These machines will not run right without a fully charged battery.