Arctic Cat 300 2x4 Red poorly running
Hi all, new to the forum from N.C. I'm seeking some assistance troubleshooting my four wheeler. It is (I believe) a 2000 Arctic Cat 300 2x4 Red. I recently purchased it for $400 with the description "needs solenoid and carb adjusted or new carb". I gambled on it and here's where I am now:
I put a new battery in it (solenoid was good) and was able to get it started and actually drive it some. The carb apparently had a problem as the drivability was poor. It would never take full throttle, and the performance seemed to constantly shift (sometimes idle fine, sometimes not, would always start, sometimes it would pull better than others).
The bike is in overall fair and complete condition. Although the bike was listed as a 2001, it has the Mikuni carb of the 2000 model, rather than the Keihin carb from the 2001 and up. After reading all I could find on the carb and CV carbs theory of operation in general, I took it apart to see what I could discover.
It appears to be in generally clean functional condition. The diaphragm is soft and not torn. The only thing I saw as a concern was the slide is visibly scuffed and worn on one side. I cleaned it thoroughly and reassembled and performance was then decreased from before. So after researching and reading mixed reviews, I bought a CCC (Cheap Chinese Carburetor) on eBay. As I only have $400 in the bike, I don't see dropping a load of money in factory parts, but maybe I'm wrong. The diaphragm and slide alone from Arctic Cat is like $131.00 by memory. Sooooo.. I bought the $40 ebay carb. A friend purchased one for a Timberwolf and it was perfect out of the box. Not so for the Cat 300. With the new carb (which looks pretty good), it fired right up, but still won't take gas as you increase throttle. In fact, it's not really driveable now. It just won't pull enough. I have read enough to know that the pilot circuit generally handles up to 1/4 throttle, the slide and needle jet/jet needle handle 1/4 to 3/4 throttle, and the main jet handles 3/4 and up to WOT.
My spark plug is always black, no matter how I adjust the carb, by my understanding meaning it's running rich. I have tried adjusting the float level, adjusting the fuel/air screw, and raising/lowering the needle, all with various but unsatisfactory results.
I have checked the petcock and fuel flows freely when open.
I have not changed the spark plug, but was assuming it was decent as the bike will fire up consistently even when cold. The choke (enrichment) system is working.
When the bike was drivable, the mechanical portion of the motor seemed tight and good. all the gears work. I checked valves and they were tight, so I adjusted them to spec. No noticeable change.
I want to conquer this project because I feel it could be a great bike, but I am at the end of my carburetor knowledge. I don't know where to get jets for the CCC.
The one thing I haven't explored is the ignition or whether there's some maladjusted rev limiter or something.
I'm hoping that someone with a passion for these, and an appreciation of keeping older thing running well, and some insight, will be able to help me figure out a next step.
Any help will be greatly appreciated... Thanks!
One last item... the intake boot between the carb and head has a slight crack in it. Very slight, but it was seeping a little fuel out. So in troubleshooting, I wrapped it well with e-tape and there is no visible sign of leakage now. I know this is only a temporary solution, but the cheapest I have found that intake is about $86 and I want to know I can get this running before I buy one. I will definitely replace with with new if I can iron out the other bugs.
Thanks again. And sorry for long post, just wanted to give full picture.