400exrider36
05-30-2017, 03:16 PM
So I ended up getting a big gun rev box a little over a year ago and after installing it, my 400 would barely start, sometimes idle, and sputter and backfire when riding. Yes, it reved higher and ran fine at high rpms, but that was it. It was around 30-40 degrees when i tried this. I rode it like that for a few minutes and put the stock one back in. More power and runs perfect. Tried it again the other day and same result with warmer weather around 70 degrees. I do have a 440 kit and a stage 2 hotcam, but jeez i wouldnt think it would act this horrible. Any thoughts? I did get the rev box off ebay for a good deal if i remember correctly...