my Carter 1BBL "high idle"/choke set screw (driver side, closest to firewall, sets cold start) ....disappeared. I didn't have it way screwed out either, so...I have no idea. But no one here has one. Closest I could find was a #8-32x1", and it was just a bit too loose (and long). Looked on Mikes Carburetor parts, and his idle screws look different from the one I have left (curb idle). Now I am left to wonder, maybe I didn't have the right screws on there to begin with, and it was making it hard to properly set my carb? Anyone have one lying around?
Sorry for such a delayed response, I have been sick:( Matt in TN, I got the 8-32 at Oreilly (but they don't fit)---the 'original' one next to the new one was my curb idle screw for comparison, as the two screws were identical (to my eye anyway).
I am located in for northern CA on the coast (Eureka).
Funny, I never see bullnoses for sale--anywhere! But last week there were not one, not 2, but THREE for sale in my town. One I have yet to go look at, it apparently has a custom Caravan Camper shell just like mine!
I will try to remember to check for that screw tomorrow. I have the same carb on my truck and maybe I can at least get you an answer on the size. but I am wondering if it being too loose is a clue as to why you lost the original one.
sorry for the delay. life on the road has its challenges. I pulled one off the shelf and checked and they are most certainly #8-32tpi . they also have the load spring which "should " prevent it from walking out. one tip which "may" help would be the use of threadlock or even roadkill thread lock. meaning crimp the threads very lightly with vicegrips to give small flat bites in the threads to give a little resistance to turning. in addition to the spring not in lieu of it. if a number 8 strips then it may be time to rethread it to 10-32. either way its a very reasonable fix.