i would start with a clutch kit. then some v force reads. clean the carbs install new plugs. the most important part is to get the throttles to open at the same time. with the boots off the carbs stick you fingers in 2 carbs and slowly pull the throttle. and adjust acordingly. then do the regular maintnence. like bearings, chaincase oil. the 1995 96 were the fastest of all th tripple 600's.
95s were not as fast as 96, 96 was flat out the best 600 triple cat made, the pipe design is why the 96 was the fastest, 96 had the same head to expasion chamber joint but the expansion chambers were different from 95-96, 96 had the ideal head pipe to expansion chamber set up and it had the best expansion chamber shape, 97+ were horrible, they had the same expansion chamber shape but the head pipe to expansion chamber joint was a bad design that robs power and its the same pipes on the 98 as the 97. Get a late model TSL rear skid I have a 2002 ZR 800 Cross country in mine, you need to move the mounts 2" forward, and do the AGLT mod to the front, I have not done this to my ZRT yet but I did it on my Z back in 2002. As far as carb set up drop the needle jet so the C clip is second notch from the top and that will get rid of some of the loading up at low throttle, then turn the idle air screws out 2.5 turns out and that gets rid of all the loading up at idle, then jet it one size down from stock, or if your like me I jet when ever the temp changes and I always run mine lean but you have to know how to ride them that way to keep them from blowing up, the ZRT 600 is one of the pickiest sleds cat makes when it comes to jetting, one size down from stock should be just fine unless it gets really cold out then you would want to put a bigger jet in it to be safe. And here is my clutching set up:
I have a 108 EXP commet clutch
Arctic Cat part #534 weights
Yellow white primary spring
the primary clutch itself does not matter but the internals do.
Roller secondary with a Micro Belmont micro slick shift clutch kit, I honestly dont know much about it as i bought the hole secondary from haydays for $20 that came off of a 97 ZRT 600. This kit can be made from buying the parts seperatly though. I cant find any info on the kit on line but here are the specs.
yellow cat spring set one notch from tightest position.
With this set up the peak RPM is exactly where it should be, but the key to making this clutch set up work good is making sure your clutches are a aligned perfectly, if they are not then the belt will get sucked into the secondary clutch and it will actually shift up right as you hit the gas going maybe 5mph, had that happen many times and clutch alignment is very very important on the ZRT 6, but if you get traction with this clutch set up you will be able to pull the skis off the ground no problem like in my pictures, its hard for me to get strait up like that because of the traction issue, 1.25" lug track just spins like hell even on hard pack a lot of times, but when it does hook up look HOLD ON. My engagement RPM is at about 5,200, I may tinker with it a little more this year but I think it works great, I just need to get traction now. Im also running the stock gearing.
Like mentioned above sync the carbs, easiest way to do it IMO is take the slide valves out of the carbs and tape the throttle WOT, and adjust the slides to sit flush and just a little bit snug to the cap, make sure they are all about the same as far as how snug they sit, then turn your idle screws all the way in, count how many turns the center one goes in, does not matter witch one you count on I just use the center one myself, then back them all out to the same number of turns as the center one or what ever one you used to count the turns on, then jack up the track off the ground, start it and see where it idles, then turn each one the same exact amount in what ever direction it needs to go, counter clock wise for lower RPM clock wise for higher RPM just make sure to turn all of them the same exact number of turns. I would stay away from V-Force reeds, The key to a good running motor is no air leaks, OEM reeds seal really well, I have seen a lot of those V-force reeds leak and make them run lean on one cylinder or more making them not synchronized, I have also seen a lot of sleds blow up from reed failure with after market reeds mainly V-Force due to either lean melt down from an air leak or from the cheaply made reed falling apart and getting sucked in. The ZRT 600 only needs minor tweaking with the parts it has to make them run extremely well, if you set them up correctly you wont believe you have the same sled.
kaw550--I had one of each yr zrt6 made (some yrs I had 2 when Cat made LE and standard models). Best bang for your buck for any yr ZRT6 is the D&D shim kit. Basic explanation : it's a thin spacer that goes below the cyl's and uses an inverted cut head (to keep squish and compression). This acts the same as posting without the need to cut and grind the cyls. Set of triple pipes, some jetting and clutching, and you'll be a happy camper ! PM me if interested in this as I'm 95% sure I still have a shim kit for the early (NON-APV) trip-6. I also have pipes and a shim kit for 01-02 APV trip-6. Most of my notes are kicking around somewhere too for jetting and clutching specs.