Mr, Baxter --

I stand corrected! I went back and looked at the sticker again on my engine (was going to take a photo) and it does indeed show the model# starting with a "41". I guess I should have put on my glasses the first time I checked!

So it looks like rameleni1's engine IS a 25 cc engine. But I'm still confused. The photo he posted sure looks like my 41 cc engine and it doesn't have the "square head" that I thought the 25cc engine has (like the pic Bill Rademacher posted). But the sticker DOES show the model# beginning with "25".