It could very well be vaccum issue, as you guys are stating! That seems like the symptoms, because it is just sitting there in the shop, and it will idle for a couple of minutes, then all the sudden it starts increasing the idle.
Where are the vaccum caps or block offs?
I put my hand over each of the carbs with the air filters off, and they all have good vaccum, but I don't see any caps or plugs at all -
Legends16 where on the carb are they (i.e. back side toward motor, on fuel rail, on outside toward fuel line in, bottom of bowl?)
No doubt I need these carbs synced, and probably jetted by professional, it's running rich, and I get a lot of backfire pop when I rev it).
Justfreaky - I am hoping for easy - simple fix! But you know how that goes....
Thanks everyone, I will try a few more things, hoping to race sunday, so I am hoping for quick fix.