So This is a new thread on AFR"Air Fuel Ratio Gauge"Im gonna throw up a quot of myself from other threads this was discussed in and than make adjustments to what I had said after I had done more testing today
Ok after further testing it's still running rich at WOT.It's only when I let off when it drops to the ideal range.Im thinking I need to go down to 150's on the mains.And at idel it's going back and forth on the first and secon bar of rich,and allt he way rich on the throttle.it's a pretty easy mod.I dident go all out and get a wide band set up,that would run $150-$200 bucks.I just wanted something that would give me a good idea of whats going on.I picked up a sun pro AFR guage on amazon for $28 shipped and a denso 1 wire o2 sensor for $25 shipped on ebay.
I Drilled a hole in the header just past the collector and welded in a o2 sensor bung,hooked up the guage,sensor and thats it.
My bike was running a little rich,I knew that befor the guage,but thats why I got it to help tune in the carbs a little better.Come to find out yesterday I have 97 YZF 600 carbs with no jet kit and they were still set to factory settings.I drilled and pop out the A/F mixture caps # 1 was at 1 1/2 # 2 & 3 were at 2 and # 4 was turned all the way in.I turned them all to 3 1/2 and now the throttle response is a million times better.It's running on the first of 3 bars on the guage rich at idle and when I rev it up,it drops back in to the happy zone of a ideal mixture.
Heres the specs on the YZF Carbs
97 YZF 600
36mm Keihin downdraft carburetors
• Main Jet #155; CA mdl = #148
• Main Air Jet #80
• Jet Needle #1,4: N3FC #2,3: N1YF
• Needle Jet 2.6
• Pilot Air Jet 1 #140
• Pilot Outlet 0.9
• Pilot Jet #38
I think the stock carbs are what?33-34mm.Im not sure if it's the stock boots,but I suspect so because I have to use the force of god to get them in there.
Any way thats all for now.Heres a link to a video I took while testing.You can also here how my exhaust sounds with the R6 Header and choped can
FZR 600 AFR Gauge Test


