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Old 05-26-2014, 03:22 PM
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Davezilla Davezilla is offline
Motorized Bicycle Elite Member
Join Date: Mar 2014
Location: San Antonio Texas
Posts: 2,710
Default Re: too rich fuel mix?

I fully agree as well, the air fuel ratio is directly related to the fuel oil mixture so I don't worry too much about carb tuning until I'm off the high oil content in my break in mix which is 16:1 Quaker State high milage oil in the first tank, this just gets between idle and mostly no load revs with a little really easy riding on for the first hour of opereation, after that I switch to 20:1 with a good non synthetic 2 cycle oil but not worrying about tuning the carb, still taking it kinda easy on the engine and no full throttle under load bursts for about 30 to 45 minutes of run time, After this I'll add in more fuel to bring the mix up to 32:1 and finish the break in on this mix where the fuel mix is more lined up with the right air fuel ratio so I may move the needle up or down on the 32:1 mix, but after that gallon of fuel is consumed, this is where I'll switch to my Amsoil Dominator 2 cycle oil and determine if re jetting is needed or not as well as which ratio I'll finally end up using. I like to run 40:1 or even 50:1 depending on oil quality. Amsoil does make a 100:1 oil that works great but I won't mix mine at those ratios unless the oil is specifically made to run in those ratios like Opti 2 or Amsoil Saber. Amsoil's Dominator and Interceptor are both designed for a 50:1 mix and it's also not uncommon for one engine to like one and not the other while another engine built the same way likes the other better and vice versa so it's also worth it to experiment with the high performance 2 cycle oils to see what your engine likes the best.
But back on the main subject, I just tune my carb enough to keep it from running lean on fuel until I'm done with the break in mixtures, then I'll tune the carb accurately once I'm on the more fuel less oil mix as it can go rich at the higher ratios.
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