"Ok guys, I'm stumped. I
"Ok guys, I'm stumped. I have rebuilt my carb and made all float choke adjustments. She starts with an accel pump shot of fuel, uses it up and shuts down. Have to have the throttle cocked a bit to get her fired up and stay running. Fuel pressure is 6-7 psi. Carb is a Edelbrock 1409 with .89 jets all round. I can live with the cruddy startup. The real issue is that the engine is acting like somethig is holding her back. I cannot reach my target RPM and I have upgraded this motor for more performance. ???
Symptom is manifested as a surge of 150RPM under cruise. Be running at 3750 and then you feel power roll on up to 3850-3900. She feels better at the higher rpm too. Like all of a sudden she is on all cyls. ??? Then she drops back to the original rpm, randomly and stays that way almost all of the time. It's those few minutes of Wooo Hoooo!!! I want back. I checked the fuel filter (inline screen type, no debris) and the ones in the carb are new. She also has new plugs, wires, cap and rotor. I have verified firing order. The performance is notably decreased on the engine when actually the opposite should be true as I have added some valve lift from a roller tipped rocker setup. The surge is worse coming off cruise to 2000rpm. She surges badly then, until I back off the throttle to settle her down a bit. I am suspecting an anti sylphon valve, gas issues, or the timing is not advancing properly. When she wants to, she is a powerful puppy. I'. not liking her now though.
As a side note, she is also heating up too quickly and the manifolds are pretty hot. You can barely run your hand over the top without toasting your hand. I have confirmed impeller operation by removing the hose to the water pump and starting the motor for a second. I get water out of the pump AND out of the impeller hose.
Trolling she gets very warm, almost touching the red on the idiot gauge, and running midway under cruise. (Still a little warm for this motor).
How likely is it that the timing is not advancing? Or is she getting hot because she is starved for gas?
My 8 year old son says I "fixed it" too much. <sigh> I think the lad may be on to something...
Thanks for any ideas..."
"Ok guys, I'm stumped. I have rebuilt my carb and made all float choke adjustments. She starts with an accel pump shot of fuel, uses it up and shuts down. Have to have the throttle cocked a bit to get her fired up and stay running. Fuel pressure is 6-7 psi. Carb is a Edelbrock 1409 with .89 jets all round. I can live with the cruddy startup. The real issue is that the engine is acting like somethig is holding her back. I cannot reach my target RPM and I have upgraded this motor for more performance. ???
Symptom is manifested as a surge of 150RPM under cruise. Be running at 3750 and then you feel power roll on up to 3850-3900. She feels better at the higher rpm too. Like all of a sudden she is on all cyls. ??? Then she drops back to the original rpm, randomly and stays that way almost all of the time. It's those few minutes of Wooo Hoooo!!! I want back. I checked the fuel filter (inline screen type, no debris) and the ones in the carb are new. She also has new plugs, wires, cap and rotor. I have verified firing order. The performance is notably decreased on the engine when actually the opposite should be true as I have added some valve lift from a roller tipped rocker setup. The surge is worse coming off cruise to 2000rpm. She surges badly then, until I back off the throttle to settle her down a bit. I am suspecting an anti sylphon valve, gas issues, or the timing is not advancing properly. When she wants to, she is a powerful puppy. I'. not liking her now though.
As a side note, she is also heating up too quickly and the manifolds are pretty hot. You can barely run your hand over the top without toasting your hand. I have confirmed impeller operation by removing the hose to the water pump and starting the motor for a second. I get water out of the pump AND out of the impeller hose.
Trolling she gets very warm, almost touching the red on the idiot gauge, and running midway under cruise. (Still a little warm for this motor).
How likely is it that the timing is not advancing? Or is she getting hot because she is starved for gas?
My 8 year old son says I "fixed it" too much. <sigh> I think the lad may be on to something...
Thanks for any ideas..."