ok to start off i have my 1998 zr 600efi le xc with a zr 500 carbed motor in it with zr600 cylinders.
according to online parts diagrams, the 600 carb and 500 carb both have vm 38's only difference is the main jet size. can anyone verify this for me?

also the airbox orinally in the sled was for the efi motor so i went to fit the carb in the rubber boot of the air box and it wayy too loose. ill have to run foam pod filterbut thats alright i like the idea anyway.

stock 500 carbs take a 360 which i have now the 600 takes a 430, since i am not running an airbox i was thinking in the 450 range does that sound about right?

ive said this in another post but ill say it again, i will be using a cdi from a 500 i talked to speedwerx and was told the 500 has a hotter cdi than the 600. which means more advanced im guessing. i like this idea also as its like running with a timing key. i just have to be careful with long runs i cant keep it a a steady throttle position for long, i don't ride like that anyway.

That all sounds right, your thinking anyway. I do not know about the 98 but my '00 600 I think had 330s in it? maybe check those jet sizes again, I could certainly be wrong. Yes very common for sleds to use the same carbs with just different jets, zr 800s and 900s are pretty much that way. You should be able to fabricat some sort of a plate (maybe use a chunk of heavy plastic like cut out of a 5 gallon pail or heavy container) to join your boot to the efi box if you wanted. Unless you are going all out to shed weight, I would avoid the filters. good for grass, bad for snow, even with the filter covers. they also sit low in the chassis and draw warmer air than the air that is pulled in through the intake/gastank assembly on the stock box.

I agree,,sounds about right, my 00 ,500 had 350 mains but the 98's had the twin horn air box and were jetted up one size,,, or atleast that's my theory,,,RU using 500 clutching and gearing also,,,should be running at about 8600-8700rpm,,, R2R

For the air box just get a boot for the carbed sled. They are held on by plastic pins. I am useing an efi box on my carbed sled. I just had to change the boot. You should be able to find a boot on here for cheap by the time the snow flies. I am running 310s for mains in my apv 600

thanks for the ideas..
im running the 600 clutching and gears. i ran into another problem just now, The guy i got the 500 parts from cut the carbs where they mount to the air box. i guess he was racing it with no filters.
now the rubber wont reach as the carbs missing about an inch. ill rig somthing up though.

Ok,,never noticed the part where you said it had 600 cyl,,,,, R2R