No such thing as a dumb question----just dumb answers and you came to the right place for that! Primary and secondary differ due to engine requirements thru the rpm range. There are exceptions to the rule. Side slung, butterflies open at same time for drag apps, worked carbs that are built for idle to W.O.T. in a heart-beat. But to generalize the question, if you are cruising along at 2800 rpm do want the same amount of air/feul as if you nailed it for a race. M
Small primaries provided good throttle response and good economy for around town driving and highway cruise. They also sounded cool when you mashed the gas...buuhhwaaaaaahhhhhhh
When I first started driving, my Mom drove a 455 GS Buick. I use to take the air cleaner cover and flip it over for a little Sat. Nite cruizing. I forgot to flip it back one nite. She gets in it to go to church the next morning with a some of her women friends. She punches it getting on the freeway, and she tells me they all about had heart attackes.Small primaries provided good throttle response and good economy for around town driving and highway cruise. They also sounded cool when you mashed the gas...buuhhwaaaaaahhhhhhh
Couldn't drive that thing again for about 3 months.
Is that the same reason why the squirters are different sizes too because of the power valve is in the front.
Although a lean condition will cause it to backfire (thru the carb), AED's are usually pretty close out of the box. Because you have "blower carbs" they are manifold referenced. Don't know your current jet size or power valve restrictor size, but it sounds as though he just fixed it by dumping fuel. Were these carbs new and un-molested or did you by them from someone who told you they are "blower carbs"
The more responses the more questions you will have and that is not a problem here. Its winter and alot of good (some bad) guys willing to lend a hand. My question would be, did it pop thru the carbs or thru the exhaust? Motors back fire for alot of reasons and intake and exhaust pops or flames narrow it down alot.
It popped through the carbs.
Then more than likely you had a lean condition and sounds like you are on the right track with going fatter. That is of course if the timing is right. Also the tune is correct.
10 sizes on the jet? That's a bad move. You need to call AED and find out what they say. Their carbs are usually right on.
The timing is 30 degrees advance, it's locked out.
Everything they do to these carbs at AED is intentional, and I wouldn't stray too far from their original configuration without checking with them. It's an easy phone call and John is as nice a guy as you'll find. You could be bandaiding another problem.
If this is a blown motor then what is the drive ratio? If you are under driving then step-up 2 or 4 degrees on the locked timing. If it luggs at 4 back it down.
