Looks like an .18 CV-R to me from looking at the carb.

I think there's a number on the carb so if you check on the OS web site you'll see what carbs are available on that engine,but I'm fairly sure it's the .18 from the blue heat sink as well.IIRC the .15 has a black heatsink.The .12 I had had a blue heatsink so it could even be a .12.

You could find that the needle housing is the same across several carbs,when I broke one like that I fitted one from a redundant OS.12 CV-R.

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