Most of the better carbs for unrestricted like 1.5 to 2 turns out on low speed air with small pipe and big pipes like 3.5 to 4 turns out. This setup is with 2 o-rings and reamed to .028 on low speed. You can swap out pipes and adjust this on back to back dyno pulls and pick up .2 of a hp. I've tested this many times.
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I’ve never used an air/fuel gage so I can’t answer that question, but I have used the EGT a lot and I know, with no doubt at all, that it works, and it’s available on most kart gauges on the market.What is the difference between EGT for tuning, and using AFR to tune?
I've never used an air fuel gauge but I have a question.AF guage gives much faster results than the EGT setup ( reacts faster) . switched to that a few years back on my dyno. EGT does work but the A/F guage can give you a look at your fuel curve for the dyno run. For me the acceleration of an engine on my inertia dyno is king to finding a better engine
EGT setup is cheaper than most any A/F guage worth using on the dyno
Just me
AF guage gives much faster results than the EGT setup ( reacts faster) . switched to that a few years back on my dyno. EGT does work but the A/F guage can give you a look at your fuel curve for the dyno run. For me the acceleration of an engine on my inertia dyno is king to finding a better engine
EGT setup is cheaper than most any A/F guage worth using on the dyno
Just me
I've never used an air fuel gauge but I have a question.
If I use regular gas and then switch to a high octane gas, how does the air fuel gauge react?
Do both, if the jetting is right, show the same air fuel ratio? It is generally agreed that low octane makes more power in a low compression engine. If you use the EGT, just guessing, would low octane fuel show higher BGT readings than a high octane fuel.
Not having ever raced a four cycle, I can't say for sure, but wouldn't the low octane fuel show a higher BGT.
Seeing as how a 0.039 jet and a .040 jet are over 5% difference in area, it must be hard to tune the thing close enough to actually get good results for any test.
That is surprising. The area difference between those two jets is 10.9%. AtThe difference between my .820" inside diameter header and 1.0" header was TWO jet sizes richer for the larger one on my BP motor. .038" to .040", very surprising. Both headers were long radius custom made and port matched to the head....no idea why such a difference.
Al is right, with fixed jets it's a pain. One size too lean the next too rich. I bought an adjustable main jet from stout racing, I can actually reach over under my carb and tweak it's T-handle on the fly if I need to.