On my 75 sportster 1000cc i get her fired up and she pops out the exhaust and it takes a few more seconds for the front cylinder to fire up.I also found when turning her over i fell air blowing out around where the carb goes into the head on the front cylinder.I wanted to know if it was just a intake leak or something with the exhaust valve.

 

I would do a compression test to rule out a leaking intake valve.....

Doug

 

to rule out a leaking intake valve so if it's ruled out then it only the exhaust valve or the rubber seal around the carb where it get clamped to the head

 

If air is coming back through the intake, it could have a leaking intake valve. A compression test will let you know for sure if there is any leakage past the valves. It will also let you know if it has a bad exhaust valve. I would start there. It is a very easy and quick test. All you need is a compression gauge to do it.

Doug