Carb Advice
#1
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Carb Advice
A friend asked me to get his Zenoah 23 running for him. After a little coaxing, It is running but the high-speed needle has no effect. Low-speed needle gets the acceleration fine but the high-speed needle can be opened 2 to 5 turns with no change.
Any suggestions for correcting this?
Any suggestions for correcting this?
#4
Most carbs are set with both needles at 2 - 21/4 from close position.
The LSN controls the engine RPM from idle to around 2/3-3/4 of the RPM range, the HSN controls the top 1/4.
You always start with the LSN and when the engine is tuned you can start leaning the HSN slowly.
OS published instructions for their Walbro heli engine: http://www.os-engines.co.jp/english/2013/130316e/
If you follow these instructions you should come right.
The LSN controls the engine RPM from idle to around 2/3-3/4 of the RPM range, the HSN controls the top 1/4.
You always start with the LSN and when the engine is tuned you can start leaning the HSN slowly.
OS published instructions for their Walbro heli engine: http://www.os-engines.co.jp/english/2013/130316e/
If you follow these instructions you should come right.
#7
If the HS needle had ever been tightened too much, it could have deformed the needle seat, opening up the orifice. A new needle would not help in this case. A deformed (bigger) seat would make tuning difficult, if not impossible. However, if the needle itself was deformed, causing a step on the needle taper, then a new needle could solve the issue. Good luck