I have just recently purchased this YS120 for a Summit 120 Patternship. I would like to know which model 120 I have and if I could purchase a manual for it. Please let me know what I need to do.
I would also like to know what type of fuel to run and maybe some good starting points for prop selection.

Thanks
Dave

Hi Dave,
I am sorry to hear of your MOM. I lost mine 2 years ago and my Dad last year. It is tough but time does help.

If you have time could you help me in the id of the 120. I need to get a couple of props and a mount order for the pattern plane.

Thanks,
Dave B

Looks like a 120FS. First model. Great engines. Try a 15x10 or 16x8 prop.

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Thank Dave for answering my post.
I have one more question. on the different 120 YS models, were there different mounting depths? The YS120FS I have seems to deep. The little screw on the carb hits the soft mount and I cannot get the spinner back far enough.
What were the depths of the various 120's?

Thanks
Dave

All the 120's vary slightly and I wouldn't hazard a guess as to those variations. I do know that the mounting hole dimensions are the same on all the 120 and 140 engines, but the placement fore and aft can vary. That's why we shim or cut the back of the mount to suit. I do know the older engines had a lot bigger variations than the current ones.