Hello all, this is my first time leaving a post, but a long time reader!! Great site!!
OK here is the skibby.
2000 Arctic Cat ZR 600 EFI: 3000miles, freshened up 250 miles ago (new rings, pistons, seals etc)
Mods: Twin Black Magic Pipe and Silencer, Black Magic Clutch Kit, 196 studs, blah blah blah....
OK, so I just bought this sled this season. I took it for a test ride of about 40miles and it ran like a fat kid at a cupcake. 300 miles later, now i seem to have an issue, when it hits about 7700 rpm it likes to bog out like its only running on one cylinder or flooding/being deprived of gas, if you back off and feather the throttle it will come back to life.... Which the first time it did it I was doing some long hill climbs with it and it caused me to roll it back down the hill-- luckily its a cat so I just dusted it off and drove away without a scratch or crack... Anyway, I read the post on disconecting the throttle safety switch (TSS) which I did, but it made on difference. (lucky me to not be something simple) Of course the next thing I thought of was a blow jug. So I got out the ol' trusty comp tester and jug 1 was 133 and jug 2 was 134 (not too bad of a ring job, if I do say so myself) and after thinking, it runs too good at lower rpm to be blown!??! Here a couple of my observations, the headlights get dim at idle (which i know is normal but they get really dim like half power), and another was that it only does it if I just go off and pin it, if I ease into it like on the lake it will run fine all the way up to 114 mph on the radar gun. Now I know that black magic has a chip or something to reprogram the computer when you put aftermarket pipes on an efi, I do not know for certain if this was done and nor did the previous owner, the mod was done a a reputable shop, and had always ran great up until now... I also thought maybe predetination because of low octain fuel, but I always run at least 91 in it and usually put octain booster in just to clean it out the first time out, it has ritually always had Arctic Cat oil ran through it and has never seen ethenol (previous owner was addiment about that). Now I do have the oil pump turned up pretty good after I put the new top end in it just for peice of mind on the break in period, but its turned up enough to where it wont foul the plugs, and I use only the new irridium tipped plugs in it, (did try the regular ones and didn't make any difference, just the IR don't foul as quick....). Does anyone have any idea what this could be, I know that there are a ton of things; ECU, clogged injector, coil pack, stator, the question is where do I start? Any insight would be very helpful, you guys are great and thank you for you time!!!
Ride it like you stole it!!!
Tony in Iowa