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DannoXYZ · February 16th, 2022, 07:17 PM

Yeah, mixture-screws really only adjust idle. Once you crack open throttle, it's pilot jets that take over.

Pinging/knocking occurs under load when multiple flame-fronts are ignited. This is caused by formation of radical alkyl groups which only arise under intense heat and pressure. These radical-alkyls are extremely unstable and ignite on their own. When these multiple fronts collide, it generates intense pressure and heat at that location. Causes the popcorn kernel in cans sound we associate with it.

But when you're free-revving engine with no load, it's not gonna ping no matter how lean it gets. It'll just sputter and die if it's too lean.

I've gotten good extra MPG by programming in 16-16.5:1 AFR under steady-state cruising zones. Anything more than 50% throttle, it'll go back to 14:1 and above 75%, 13.5:1 is where max-power is generated on NA engines.

In this case, I suspect further carb-cleaning is needed. Bike ran perfect fine off show-room floor with factory jet sizes. It can again once carbs are factory-fresh clean. Did you poke out lateral bleed-holes in pilot-jets? Dried-petrol form plastic-plugs and you'll push them out like little grains of sand. Also work from other end and poke out bleed-holes in carb-venturi.

February 16th, 2022, 07:17 PM	#255
DannoXYZ ninjette.org certified postwhore Name: AKA JacRyann Location: Mesa, AZ Join Date: Dec 2011 Motorcycle(s): CB125T CBR250R-MC19 CBR250RR-MC22 NSR350R-MC21 VF500F CBR600RR SFV650 VFR750F R1M ST1300PA Valkyrie-F6C Posts: A lot. MOTY - 2018, MOTM - Nov '17	Yeah, mixture-screws really only adjust idle. Once you crack open throttle, it's pilot jets that take over. Pinging/knocking occurs under load when multiple flame-fronts are ignited. This is caused by formation of radical alkyl groups which only arise under intense heat and pressure. These radical-alkyls are extremely unstable and ignite on their own. When these multiple fronts collide, it generates intense pressure and heat at that location. Causes the popcorn kernel in cans sound we associate with it. But when you're free-revving engine with no load, it's not gonna ping no matter how lean it gets. It'll just sputter and die if it's too lean. I've gotten good extra MPG by programming in 16-16.5:1 AFR under steady-state cruising zones. Anything more than 50% throttle, it'll go back to 14:1 and above 75%, 13.5:1 is where max-power is generated on NA engines. In this case, I suspect further carb-cleaning is needed. Bike ran perfect fine off show-room floor with factory jet sizes. It can again once carbs are factory-fresh clean. Did you poke out lateral bleed-holes in pilot-jets? Dried-petrol form plastic-plugs and you'll push them out like little grains of sand. Also work from other end and poke out bleed-holes in carb-venturi.