I have both, an original 3w100 and a 3w100iB2, I'm not that familiar with 3w yet, are these engines the same? They look identical

The "b2" in the model # denotes two cylinders and the "i" is a rear carb configuration.

Your engines are probably the 100b2 models, as I don't think they were made in any other configuration.

I think the last of the 100's made may have had the thin walled cases like the current 106's do. Can you post a picture?

Mike

You're right, it is the B2

Hey Mike, the sticker on this engine says iB2, but it's not a rear carb, I guess someone needed to do something with a iB2 sticker LOL

Yea, I now realise I got the "i" thing wrong there after some searching around...........

I Need to do some more research here before I post, thought I had it right, but it's not

MIKE!!! you made me pull off that STICKER! What am I going to do with you?, a lot of thier "i" engines are rear carbs, some are not

MY Sticker Whaaaaaaaaaaaaaaa

Sorry about the sticker, what does the label on the other engine have on it? if there is one.

BTW, I have a early model 106ib2 with a 100ib2 decal on the case because I'm told the 106 stickers were not available at the time.

Go figure.

The other engine has no sticker or designation on it at all, I think it's the original 100 or maybe they came off. I see you're in MD, would you happen to know Steve Stricker?

The year the engine is made should be in the serial number.
What do you have for serial numbers?