So I did a leak down test on my 400ex that has 30- 40 hrs on rebuild as it’s smoking badly and I have air blowing through carb and also through bottom end where timing inspection cap is .could it be 2 issues intake valve and rings ?? And how likely is it for both to go at same time with the hrs on rebuild. Also did a comp test and I’m getting 175-180 which I would think rings are good .any input would be appreciated