Well I just used a hole saw and drilled a 3/4 hole in the air box and runs like it should so not really sure what happened but it runs good now

I do have the u shaped tube I had it on for as long as I had the sled

I put a pipe camera down the pipe and can see the baffle and nothing else inside the pipe. So does the exhaust actually go through baffle or around it can't seem to get the camera tube past the baffle and hard to get inside the baffle

Yes stock muffler is it possible that something could be lodged in the muffler or baffle?

Rev limiter had been unhooked for about 20 years and springs and clutches are all good also. Is there a possibility that there is something in the pipe that is restricting the exhaust and when the air box is off it is getting more air/pressure to blow past whatever could be in there?? With the air b...

Yes that all checks out correct it is just mind boggling I parked it last year running and this year I have this going on right from when I took it out of storage so what on Earth could have happened through the summer is just confusing as heck iparked it the same spot/way I have the last 10 years

Yes factory air box

Thanks for the post I even took out the screen and there is nothing in the air box wide open also i can just slide the air box in and out without touching the wires or cables and does the same bogs when in and runs great without even if you just move the airbox back of the carbs it seems to run better

Hi I have a1980 440 liquifire. Ran great all last year come to take it out this year and and won't really go past 5000 rpm and just bogs. Took carbs and fuel pump apart all clear put back in same thing just bogs took all out again and all clear put back on this time without the air box and runs perf...