I'm having a really tough time with this carb. Over the weekend i finally got the idle right, or so i thought, turns out the secondaries where all the way shut, there's an adjustment screw to open them alittle to allow more airflow at idle. This is what Quick fuel recommended i do because i couldn't get idle speed up with the primary idle speed screw, and the carb was not responding to idle mixture adjustments. After opening the secondaries plates a hair i was able to set my idle mixture (tac + vac gauge) and correctly trim idle speed with primary idle screw.
I had the engine idling at 1000-1100 right where it was with the Qjet, that's where my cam manufacture recommends i keep it idling at. Parked it over the weekend and fired it up Sunday to go for a cruise, ****ing thing will not hold an idle, and now when it stalls at a stop light with the engine up to temp (160-190f) it's having hard starts.
Also i went from a 72 to a 74 primary jet size, and it still surges at part-mid throttle cruising, it's fine when accelerating. At WOT it's fine as well, my plug reading is giving me a slightly lean reading. The surge is light, i figured going up 2 sizes would cure it but it still surges the same. It surves between 1900-2700 RPM cruising, fine on acceleration.
The engine is absolutely in time( had to go back and check for peace of mind), solid compression on check, it's a fresh engine with somewhere around 100 hours. With the Qjet carb i never had any of these problems. I pulled replaced the Qjet because at the time i THOUGHT it was leaking fuel, turns out it was a heatsoak issue and the fuel was boiling out of the vent. That's since then been resolved with a 1.5" plastic carb spacer.
The only off thing about this carb was when i unboxed it i noticed the accelerator pump was way loose, it had not been preset from factory, Quick fuel said that was strange as all carbs should be preset. Is it possible this carb has some internal issue?
At the end of the rope with it, if i can't nail this problem i'm buying a spacer for my Qjet and re-installing.
Carb is a Quick fuel hotrod series 780CFM vacc sec.
I had the engine idling at 1000-1100 right where it was with the Qjet, that's where my cam manufacture recommends i keep it idling at. Parked it over the weekend and fired it up Sunday to go for a cruise, ****ing thing will not hold an idle, and now when it stalls at a stop light with the engine up to temp (160-190f) it's having hard starts.
Also i went from a 72 to a 74 primary jet size, and it still surges at part-mid throttle cruising, it's fine when accelerating. At WOT it's fine as well, my plug reading is giving me a slightly lean reading. The surge is light, i figured going up 2 sizes would cure it but it still surges the same. It surves between 1900-2700 RPM cruising, fine on acceleration.
The engine is absolutely in time( had to go back and check for peace of mind), solid compression on check, it's a fresh engine with somewhere around 100 hours. With the Qjet carb i never had any of these problems. I pulled replaced the Qjet because at the time i THOUGHT it was leaking fuel, turns out it was a heatsoak issue and the fuel was boiling out of the vent. That's since then been resolved with a 1.5" plastic carb spacer.
The only off thing about this carb was when i unboxed it i noticed the accelerator pump was way loose, it had not been preset from factory, Quick fuel said that was strange as all carbs should be preset. Is it possible this carb has some internal issue?
At the end of the rope with it, if i can't nail this problem i'm buying a spacer for my Qjet and re-installing.
Carb is a Quick fuel hotrod series 780CFM vacc sec.