Ok guys I recently put the single carb kit on my 35 vanguard also has marsh mellow exhuast with no baffles I took it out the other day put couple hrs on it ran fine no problems but when I checked the plugs one cylinder was running pretty lean and the other was perfect kinda confused on y it would do this Any ideas?

Maybe an intake leak near the lean cylinder?

Gonna take the carb off and look over every thing tomorrow but any more ideas would be helpful

Definately check the intake gasket like he said, also check your valve adjustments and it would be nice to do a leakdown test to see if that intake valve is leaking. Assuming all that suff is good then you jet the carb to be a happy medium between the two cylinders. Your stock carb has two different main jet sizes. Briggs knows that the two cylinders dont breathe equally. If all you have is an exhaust then the stock mikuni jet is usally enough but you might have to jet it up a bit.

I know my stock carb is no comparison to what you have, but i was running lean, checked valves and 1 side was tighter than a bass fiddle... And i only had 7hrs on it

Cool, hope it fixed it

Messed with the carb and intake no diffrence checkin valves tomorrow hopfully I find the problem

Had to loosen up the valves help plug color a little bit but still not where they should be I'm pretty sure no back pressure is causing this but am I able to jump up to a 167.5 with out getting cylinder wash?

Show us a pic of your "lean" plug.

All stock other than the carb and exhaust? I bet you have a Cheshire cat hiding in there.