Adjusting Fuel/Air mixture
04-25-2009, 12:31 PM
#1
Super Byrd
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Join Date: Aug 2008
Location: Cumming, Ga
Posts: 356
Adjusting Fuel/Air mixture
I need to adjust my mixture screw and was wondering what ya'll have found to be the best way and/or tool. I have one that is made to adjust ones on cars, but the flex is to long.
04-25-2009, 05:33 PM
#2
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SuperSport
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Location: Hamilton, Ontario, Canada
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Motion Pro makes two kinds of mixture screw adjustment tools. The expensive 90 degree gear drive one has a "D" adapter for the Honda mixture screw. Some people remove the mixture screws, dremel a slot in them and use the cheaper Motion Pro cable drive adjustment tool. A member of this site posted plans for a homemade tool that some have had success with. I wasn't able to find the posting in the course of a quick search. Factory Pro provides an adjustment tool with their jet kit. Other people take it to a shop. I didn't find the cheaper Motion Pro tool to be very precise. It's just a cable drive, the mixture screws are a bit tight and there's a fair bit of flex in the cable. I had difficulty using the expensive Motion Pro tool on the front carb. The clamp on the front carb boot interfered with access. I was having trouble getting jetting right so I took the VTR to a shop with an dynomometer and an exhaust gas analyzer. The shop didn't do the work but gave me some guidance about which way I should go with jetting. I adjusted the mixture screws with the Factory Pro tool when I had the carbs off the bike. I ended up with 1.5 turns out with 48 pilot jets. YMMV. It was close enough, I was po'd after fiddling with it and I wanted to ride.
04-25-2009, 09:15 PM
#3
Super Byrd
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http://www.pitposse.com/po90de14inhe.html
were you talking about this one. I thought about getting, but not if you had trouble.
were you talking about this one. I thought about getting, but not if you had trouble.
Last edited by Byrdman; 04-25-2009 at 09:18 PM.
04-26-2009, 03:21 PM
#4
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Byrdman, that's the one I'm talking about. Another member of this forum just rotated the clamp that was interfering with the adjuster. I guess the tool could be ground for clearance as an alternative. It's a good product. Maybe I'll try it again.
04-29-2009, 07:34 AM
#5
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IIRC, the Motion Pro tool is too big to fit in the small space allowed. The only tool I've found is the stock Honda tool. The little bitch costs $125. That's too much for me, especially for a "one time use" tool. It's more economically feasable to speak to your service manager at the dealer, ask if they have the tool, and bring over a dozen or so donuts on Friday morning in exchange to use the tool for 10 minutes. They guys at the shop sure appreciate it!
04-29-2009, 09:02 AM
#7
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Location: Portland, Oregon
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i have the motion pro tool and it works ... with a little help. 
the MP tool comes with 5 bits including the D style bit, which doesn't fit well.
the Factory bit that comes with the jet kit is a LOT better. i decided when i did a cleaning tear down to just slot the A/F so now i just use the flat blade bit in the tool.
i adjust the rear from the left side and the front from the right.
tim
the MP tool comes with 5 bits including the D style bit, which doesn't fit well.
the Factory bit that comes with the jet kit is a LOT better. i decided when i did a cleaning tear down to just slot the A/F so now i just use the flat blade bit in the tool.
i adjust the rear from the left side and the front from the right.
tim
04-29-2009, 03:29 PM
#8
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SuperBike
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I bought the cable driven MP carb tool eons ago from JCW. When I got my VTR, I cut the end of the FP "D-bit", ground a notch in the opposite end and epoxied it onto the flat blade on the MP tool. Works like a charm and both carbs can be adjusted with the tank on from the right side. Total cost $20.
05-05-2009, 05:01 PM
#9
Super Byrd
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05-05-2009, 06:29 PM
#10
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