What a great forum. I just purchased a 1979 7eca, on take off at full gross the tach only shows 2300rpm, full power at cruise shows 2500rpm at 2000msl 40 degrees, the engine has new cyls, 150 hours ago, new carb 20 hours ago and 100LL fuel. Is this a normal tach reading ? Thanks, Mike
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low tach readings
- Thread starter bigmikeo
- Start date
big mike:
Could be a number of reasons. First thing you should do is get an electronic tach and check it against the mechanical one installed. Ask around the local field; someone should have a hand-held tach. For sure a mechanic will have one.
If the tach checks out, you may have a 'cruise' prop installed, and the engine just can't generate enough torque to spin it any faster. Several hundred dollars can change the pitch for better performance (but possibly a lower top speed).
You may also want to check the throttle linkage to make certain it's opening all the way. Check the air filter. Check for sufficient fuel flow at the carb; remove the line, open the valve and see how long it takes to fill a known volume. Compare this to full-throttle consumption. If all else is normal, there may be a partial blockage in the muffler.
There's no simple answer. Sorry.
Jon B.
Could be a number of reasons. First thing you should do is get an electronic tach and check it against the mechanical one installed. Ask around the local field; someone should have a hand-held tach. For sure a mechanic will have one.
If the tach checks out, you may have a 'cruise' prop installed, and the engine just can't generate enough torque to spin it any faster. Several hundred dollars can change the pitch for better performance (but possibly a lower top speed).
You may also want to check the throttle linkage to make certain it's opening all the way. Check the air filter. Check for sufficient fuel flow at the carb; remove the line, open the valve and see how long it takes to fill a known volume. Compare this to full-throttle consumption. If all else is normal, there may be a partial blockage in the muffler.
There's no simple answer. Sorry.
Jon B.