Rx1 poor idle and burble on low end

[snowrules]

Have a 2003 rx1 with ecp filter kit and evac setup, hauck intake and exhaust cams, head shaved 10 thou, custom port and polish by myself and a white knuckle qc1 exhaust. my problem is i can not get rid of a low end burble. almost sounds like the sled is missing around 5 to 7 thousand rpm. all 4 coils are new last season, with new cr10ek plugs this year. carbs are clean. i am running 165 main jets i have tried leaning out the needles one clip and richening them one clip with no good results. i have the stock 17.5 pilots and have tried adjusting the fuel screws from 1 turn to 2.5 turns doesn't seem to help. my next step is trying the 20 pilots as i have read that sometimes this cures the problem but i figured if i set the fuel screws at 2.5 that this would be close to stepping up the pilots and i would see an improvement but nothing. have also tried opening the choke slightly but does not seem to help. i adjusted the floats and fuel level is bang on using a clear tube to measure on all 4 carbs. only thing i havn't done is sync them wich if the pilots don't help is my next step. anyone have any ideas on what could be causing this? in the colder weather the burble is slightly better but not much makes me think it's running rich but all the research ive done on this site seems like that is never the case. i am stumped and it's driving me crazy. also after doing a wide open run down a lake for almost 2 miles if you snap the throttle closed let it coast a second or 2 and get back on the gas again to the bar it just bogs and has a hollow sound have to blip the throttle a few times to get the power back almost seems like float bowls are empty not sure if that helps to diagnose it. sled idles fine when it's cold but after running it on the trail for 30 mins or more it will not idle. idles for maybe 15 20 seconds at set idle speed then idle speed drops and it stalls. have my idle speed set at about 1500-1800. also when the sled is warm it is really hard to start will not start unless i give it 1/4 throttle or more. thanks

 

[yamahamaniac]

I'm no pro or anything but from reading a TON of posts on here I would say sync your carbs, clean them again, and according to Len Todd, ty tech adviser, the fuel screws should be set to two turns out from the bottom. Hope that helps you in some way or another. Len also says something about checking to see if there is a light show coming from the coils, do this in a dark room.

 

[snowrules]

ya gonna check the coils this weekend

 

[snowdawg]

Sync the carbs will make a world of difference if there off.