hey all, first post here and probably a long one but im hoping for some help before i start losing hair over this sled. little back story, i originally bought this sled (02 mxz rene 800) about 6 years back, had a fresh rebuild on it at the time but i was dealing with what i assumed was massive over oiling issues, ended up changing the check valves on block oil lines and cleaning carbs etc all the basic stuff. still fouled plugs like mad but pulled like a freight train. ended up selling the machine and through dumb luck this past fall i wound up with it in my possession yet again.
skipping forward to now, it sat for a while and didnt run, as i was working on it, i ended up having to replace the carbs as a broken mix screw was found on one(happened with previous owners) and replaced oil pump with another used one and set properly including return spring mod so its not to stick open. ended up with a set of hooded rev carbs running original needle(9zly2-58), 17.5 pilots with the 520N mains. took it out for a test it idles OK and runs super rough on acceleration and i could not pull more than 6k rpm and still super oil rich, sounded like it was blown. i checked comp 140mag and 145pto.
also did some research and found with hooded carbs leaner jets are needed, dropped down to a set of 420s. now when i honk on it, its very rough accelerating(ALMOST like its running on one lung) but once on the very top end it clears up and can pull full rpms and starts to sound healthy again. but from idle up to top its just trash.
its hard to tell on a brand new set of plugs and being oil rich how the fuel is but something just doesnt seem right to me. im hoping someone can chime in and get me pointed in the right direction.
Edited by Axel751, 18 January 2021 - 11:05 AM.