ORIGINAL: Dauntae

If the engine is mounted inverted it sounds like fuel is pooling into the head, I just read a trick to fix it if thats your issue, Forgot who came up with it but put a few washers between the engine mount and engine on one side only to angle it a few degrees so the fuel won't be dead center of the head cooling the plug at lower idle. when the plug cools it will give bad transition until it heats back up at higher RPM'S

Dauntae