Originally posted by pttf
Hey
I got a STS .28 there with my SS, Ive had the 21 and i currently have S-25 in my other savage, so ive got a idea what im doing when breaking in a engine, im no expert or i wouldnt be askign for help. But i started up the sts and thats no problem. I have the throttle completely closed expect for the millimeter so that it can idle. Once it idle's for a couple of seconds it starts to rev up. I tought it just revving up for a sec, until i heard it change gear and carryed on revving. Ive stopped the engine and started it up 3 times again and it does the same thing. I dont want to start it up again and leave it as i dont want to ruin this engine. Can nebody please give me some idea why it is doing this. Ive never had this problem befre on breaking ina a engine. Im gathering it has a air leak somewhere becuase it must be getting the air somewhere for it to be doing this.
It seems the fuel supply is not enough when idling. Check those parts;
1)the low speed needle too lean?
2)the back pressure of tuned pipe is not enough?
3)manifold gasket broken?
4)fuel tank's cap leaking?
5)back pressure line or fuel line broken?