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Specific jetting question for my 7R

1037 Views 8 Replies 6 Participants Last post by  jeeps84
I have searched past threads but didn't find anything that specifically answered my question. I have found through various sources that the 7R actually runs rich from the factory instead of the typical lean condition of most sportbikes. How rich, I have no idea but I do know that my 7R will backfire (blue flame out the can) after sitting during high humidity. Now, it is said that adding an aftermarket slip-on, bolt-on, or full exhaust will lean the bike (severity based on type/style/manufacturer). My 7R has a Yosh RS-3 bolt-on.

I was planning on buying a stage 1 jet kit over the winter but what purpose would it serve if I am already running more fuel than air? I am assuming that the purpose of a jet kit is to utilize larger jets (not smaller) forcing more fuel through the carbs to richen a lean condition. Can you go with smaller jets to lean a rich condition? Is it better to adjust the factory jets? I am not sure what I am going to do but I want to fix this over the winter. I am also entertaining the idea of a full (Akra) system with new jetting.
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Larry's right of course, but just because you have a backfire doesn't mean you are running rich. Does the backfire sound like popping or gunfire? Gunfire is an explosion in the cylinder with the exhaust valve open. Popping is excess gas burning in the exhaust.

First, I would pull all four plugs. If three of them show lean running and one shows black, that carb has a float or float valve problem. If the plugs indicate a fuel problem I would get a jet kit. I've read that GSX-R's run rich, but most older Kawi's have a lean stumble right off idle.
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