dirtypool

My Feedback: (6)

I have 2 Ryobi weedie engines. I think one was from a Ryan weedie but appears Ryobi.
The head cooling fins look different on them. One has the top fin (closest to the spark plug) pretty much the same size as the other fins and the other head has a small first fin. Are they both 31cc or is one a 28cc? For the most part, they look the same otherwise.

Also, is the machining of the flywheel necessary? Why is it only machined down to the shaft boss? If machining is for weight purposes, why dont you remove all of the fins since the magnet is counter balanced?

I see a lot of talk about the single ring and the (de)compression groove. Do these really make a big difference? I see posts both ways on that.

If Ryobi weedies are so underpowered, what should we be buying? Chainsaw?

I have searched the forums and read all I can find on the subject but these questions still remain.

I have one Mac 28cc in an Ultra Stick (non-lite) with C&H ignition that I bought converted. Havent flown that yet. The ryobi's are for some variations of the Big Pink!

Thanks.

Rob

av8tor1977

My Feedback: (6)

Guys, I know this one was answered; (how to tell a Ryobi 28cc from a 31cc), but I don't remember how and I just did a search and couldn't find it. Any help? I'd like to know as well.

Thanks,
AV8TOR

farley9n

The engine with the small first fins around the spark plug is the 28cc version. Most of the parts will interchange between the two especially if they are earlier style engines......Bob

av8tor1977

My Feedback: (6)

Thanks for the answer. A clarification; how much smaller are the upper fins, and how many? I have one with the two top fins just slightly smaller than the lower ones. Is that a 28cc??

Thanks again,
AV8TOR

dirtypool

My Feedback: (6)

I can post a pic tomorrow.

Thanks for the info

dirtypool

My Feedback: (6)

Here are the pics.

The one on the right is the 28cc I guess.

So, does the flywheel need to be machined for weight or drag (load on motor)?

Thanks.

Rob

av8tor1977

My Feedback: (6)

Thanks! That's a relief, as mine is a 31cc then.

Take care,
AV8TOR

CButzin

thanks i was try to find what i have too i have the 31cc but someone made it in to a glow