MS660 sprockets

[ex-Engineer Wannabe]

We've got some large logs to buck up soon, so we're going to add a 28" ES bar to our Stihl inventory. 

We intend to use this bar with our MS660, but the Stihl factory sticker that comes on the 3003 000 8830 (3/8" pitch, 0.050" gauge Rollomatic ES bar) packaging does not list the 660 (or an 066 for that matter).

We already have a few new 33RSC-91 (3/8" pitch, 0.050" gauge) chains that we would like to use with the new bar, but now we're wondering which size powerhead sprocket to use ...

Can anyone tell me which size sprocket works with the MS660 / 3003 000 8830 / 33RSC-91 combination? 

The Stihl factory sticker on the guide bar package lists both the 7 and 8 sprockets; hence, the confusion.

Thank you for your time ...         

[Cut4fun]

Stock 660? I would run a 7T for the torque, but I am bad about pushing in the cut. If you have a 8T on hand run them both and see what you like. You can run either, personal preference  is your choice.

[Mad Professor]

We've got some large logs to buck up soon, so we're going to add a 28" ES bar to our Stihl inventory. 

We intend to use this bar with our MS660, but the Stihl factory sticker that comes on the 3003 000 8830 (3/8" pitch, 0.050" gauge Rollomatic ES bar) packaging does not list the 660 (or an 066 for that matter).

We already have a few new 33RSC-91 (3/8" pitch, 0.050" gauge) chains that we would like to use with the new bar, but now we're wondering which size powerhead sprocket to use ...

Can anyone tell me which size sprocket works with the MS660 / 3003 000 8830 / 33RSC-91 combination? 

A lot will depend on hardwood vs softwood and how you set (file) the rakers. If you bog with the 8T set the rakers higher and/or go to the 7T

The Stihl factory sticker on the guide bar package lists both the 7 and 8 sprockets; hence, the confusion.

Thank you for your time ...         

[Ed]

Stock 660? I would run a 7T for the torque, but I am bad about pushing in the cut. If you have a 8T on hand run them both and see what you like. You can run either, personal preference  is your choice.

Yep.
My 066 had the 8T on it when I got it (used). After one trip to the woodpile it was replaced with a 7T.
I use 20, 24 & 36 bars for the saw and prefer the torque of the 7T.

Ed