air/fuel circuits
- Ledkz1300
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- GertRoewer
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Re: air/fuel circuits
7 years 11 months ago
I once acquired a brand new full carb set that had been taken from a customer's bike. His bike refused to idle on #5 cylinder and the dealership tried to tune out the problem but failed. They fitted a new set of carbs and the problem was solved. What I found was that the mixture being delivered to #5 cylinder was over rich--beyond any relativity to a stoichiometric air/fuel ratio. I found that there was a restriction in the air-idle circuit on that carb, and eventually found where it was by drilling out some of the small blanking plugs in the carb body. Under the diaphragms there is a small blanking plug on side of the carb. I carefully removed the plugs with a two mm drill and a fine self tapping screw. In the gallery thus exposed I saw a small brass air jet in each. One of them (the one on #5 cylinder) looked to have some sort of corrosion on it. I have some very small jet drills and carefully cleaned the dirty jet with a drill and compressed air. Made some new plugs and fitted them and from then on the carbs worked as intended.
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- scotch
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Re: air/fuel circuits
7 years 11 months ago
An interesting approach. Don't believe I've ever heard of anyone actually drilling out the blanking-plugs to get access to "above" an idle jet. Naturally; wondering why you didn't remove the slow-speed jet-cap and then the idle jet, to clean it. On a new set of carbs there should not have been any issues removing the idle jet. Glad it worked out - regardless.
The "Cleaning Tool" was designed to deal with air and fuel passage blockage issues. Minor blockages can be sometimes cleared without disassembling the carbs. (carbs must still be removed but can remain as a complete assembly). Just remove the fuel bowl drain to allow the cleaning fluid (Lacquer-thinner) and the debris to flush out. To ensure a full and thorough cleaning the carbs must be stripped.
The "Cleaning Tool" was designed to deal with air and fuel passage blockage issues. Minor blockages can be sometimes cleared without disassembling the carbs. (carbs must still be removed but can remain as a complete assembly). Just remove the fuel bowl drain to allow the cleaning fluid (Lacquer-thinner) and the debris to flush out. To ensure a full and thorough cleaning the carbs must be stripped.
1980 KZ 1300 sr# KZT30A-009997
Always High - Know Fear !
Always High - Know Fear !
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