Another jetting question

[GMC400ex]

I know you get burnt out on these questions but this one is personally lil different. I am working on a fallen friends four wheeler that hasn't been messed with in years since he passed away he is actually the person who introduced me to 400ex and now his brother and I are working on getting it back. It runs fine now lil bit of a high idle but needs to be rejected bad. Pops and cracks on after letting out of it. Smells lil rich but has symptoms of lean with smoke (which partly could be rings) however I need a good starting point on jetting. Here are mods:
Open air lid
FMF power core
Elevation- 800 ft
Thanks in advance this projects means a lot to me

[GMC400ex]

Using fmf jet kit

[GMC400ex]

Bump any suggestions?

[killer454]

have you checked the intake for a crack it is between the carb and cylinder head.this will cause poping on deceleration.mine was broke and did the same thing,it will show a lean condition.

look at my 400ex specs in my reply might help you get started

[GMC400ex]

Yeah I had something similar to that happen with the warrior I'll check it out
Ok man appreciate it