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Showing results for tags 'air fuel mixture'.
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This is something I've been dealing with ever since I took my 99 RSV into the dealer a few years ago to have them fix my carbs because gas was pouring out of my overflow tube on the left side. They fixed that problem, but ever since my gas mileage has been on the low 30's. Black Owl and I have carb tuned it and last year at Pork in the Pines I used the color tune to check the fuel air mixtures. The fuel air mix appeared to be ok with a nice blue flame in each cylinder. But I've had all winter and spring to get up the courage and start adjusting the mixture on each carb. So I started by turning each mixture screw in 1/4 turn then running a few tanks of gas to see if things improved. After the second time there was a little mpg increase to about 36mpg (up from 34) and the nasty gas smell was gone. So I tried a third time. Mileage went down a bit and the gas smell came back. By this time I had turned each screw in 3/4's of a turn total. I had read on these forums somewhere that you should start with the mixture screws at 2 1/2 turns out if say you were rebuilding your carbs and needed to start at a base line. So last night I carefully turned each screw all the way in while counting the turns and reset each one to 2.5 turns out. Here are the counts for each carb as I turned the mixture screws all the way in. carb #1 3+ turns in carb #2 3+ turns in carb #3 2 3/4 turns in carb #4 2 1/2 turns in This after I had already turned each in by 3/4 turns over the past month. Questions: 1. Were those mixture screws out way too far? 2. Did I do the right thing by adjusting them all to 2.5 turns out? It runs pretty good today. I have not ridden far enough to see if MPG changed. 3. Is there a better tool besides the colour tune to determine air fuel mixture? It is pretty subjective as to the correct color shade of the blue flame. If not, I may beg to borrow a colour tune again. 4. I know I should re-sync the carbs after all this. Black Owl, you got the time to help? 5. is there anything else I should check? ============================== Update I should have mentioned the plugs are good. I replaced them last fall. Only about 4k on them. The headers heat up evenly, I already thought of that. I should buy stock in seafoam as I use so much of it. (1 can about ever other month) I don't have a tach, but I did buy a meter that is supposed to measure RPM with a clamp over the #1 plug wire. 1000RPM?? Really that high? When I pulled the old plugs last fall at Pork in the Pines, they looked good. Nice tan color to them. No clue on the AIS. I bought this bike used a few years back. No popping on deceleration anymore. There used to be popping before I took it in for repair a few years ago. HOWEVER, I had amazing Howitzer like backfire almost on command during deceleration until I started adjusting the mixture screws. Update (again): I have K&N air filters and I take care of them routinely.
