Home › Forum › Ask A Member › 49 TD20 Low-speed needle affecting high speed performance? › Reply To: 49 TD20 Low-speed needle affecting high speed performance?
Maybe focus on the high-speed side. As you mentioned, the high speed adjustment doesn’t seem to make any difference in the RPM’s. When working properly, the high speed adjustment will range from overly rich to overly lean and can shut the motor down.
Regarding the low speed packings, they are very durable and most of the time can be saved. The low speed system has a check valve that must be working properly to achieve an idle. Also, loosening the packing nut, removing the LS needle, and pumping the primer can be helpful in cleaning the LS system.
The Pochefamily website is very useful. Basic Carburetor Servicing Johnson H and T Series (pochefamily.org)
P.S. It’s good to see steveh on the forum!
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