SteveSr
Well-Known OPE Member
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- Dec 14, 2016
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Hello,
According to the attached Stihl tech note stihl made a cylinder change to the 4137 powerhead. If I am interpreting the attached warning it would seem to indicate that the OLD cylinder (which I have) cannot be used with the NEW carburetor(s) (see 3.2.5 Summary) which is all that you can buy these days. Is it possible that the changes in the transfer port time is enough to change mixture requirements enough to cause a lean condition and the mentioned engine damage with the newer (leaner , less adjustable) carbs?
BTW, I checked back to other TNs and the change to a limited ignition coil was in 1997 so this doesn't seem to be engine over speed damage that they are warning about.
Thanks for any insight,
Steve
According to the attached Stihl tech note stihl made a cylinder change to the 4137 powerhead. If I am interpreting the attached warning it would seem to indicate that the OLD cylinder (which I have) cannot be used with the NEW carburetor(s) (see 3.2.5 Summary) which is all that you can buy these days. Is it possible that the changes in the transfer port time is enough to change mixture requirements enough to cause a lean condition and the mentioned engine damage with the newer (leaner , less adjustable) carbs?
BTW, I checked back to other TNs and the change to a limited ignition coil was in 1997 so this doesn't seem to be engine over speed damage that they are warning about.
Thanks for any insight,
Steve
