How much does temperature affect motor?
Because on this much I agree with AJ. Thats a big drop in rpm between neutral and drive for a stock engine.
A big drop usually happens when the idle is too lean for the conditions.
In which case the hotter the engine gets, the worse its going to be. There's cold, warming, and really heat soaked. Heat soaked is where its at after a couple hours on the interstate.
Throttle position at idle: It should show between .20 and .040 " of transfer slot.
see photo here: Holley idle mixture screws
The idle port supplies the rest of the fuel at idle. See illustration in the post linked above. This is the portion the idle mix screws control. If the mix screws can be turned in enough to kill the engine, the setup is at least in the ballpark.
I'm no expert plug reader but these are examples of rich, amonst other things.
Champion (left) Autolite (right)
When you say the engine is happiest at 14-15" initial do you mean it idles strong (high rpm) in neutral or in gear?
Because on this much I agree with AJ. Thats a big drop in rpm between neutral and drive for a stock engine.
A big drop usually happens when the idle is too lean for the conditions.
In which case the hotter the engine gets, the worse its going to be. There's cold, warming, and really heat soaked. Heat soaked is where its at after a couple hours on the interstate.
Throttle position at idle: It should show between .20 and .040 " of transfer slot.
see photo here: Holley idle mixture screws
The idle port supplies the rest of the fuel at idle. See illustration in the post linked above. This is the portion the idle mix screws control. If the mix screws can be turned in enough to kill the engine, the setup is at least in the ballpark.
Might want to check for those holes under the exhaust ports... Dont ask me how I first learned about them...
Check the fuel level in the bowls.
I'm no expert plug reader but these are examples of rich, amonst other things.
Champion (left) Autolite (right)
