The least of your worries is engine size. A 10 hp would be plenty or even an 8 hp. A RER drive system is not made to haul heavy loads.

Walt Conner

Aww, go pull yer cart with yer RER! I have a Snapper 12 h.p. RER, made in '83-4, 12 h.p., 33 " deck, which i have used for many years since i bought it new in 1983-4. Best thing i have ever used for that work, and for mowing, too. I tried using an old small tractor for it, and promptly pulled a gear in the rear end!
Rustyj

Thanks for the replies. Can you tell me what the difference is between the 2? Is it that the larger blade needs more hp to turn it? I know nothing about this stuff cept to wear them out...ha ha

I understand Walt. Basically I just use the dump cart for working around the yard for mulch and such. Nothing major.

I don't think the blade size has much to do with whether it needs a bigger engine. The smaller one i have has an 8h.p. on it, and it pulls the yard carts easily. The 12 hp does just as good. Never had any trouble with either one, but i don't haul rocks or dirt, just small logs, leaves and grass.
the thing i like about it is the fact that they are not top heavy, as a tractor seems to be. I can whiz around my sloped yard at speed and have never had so much as a tilt, or upset. But, beware of starting out up hill, with a full or partially full grass catcher on the back! (Especially in gear!) The machine will rear up, like a startled horse, and scare the bejabbers out of ya! They are great for chopping leaves and blowing them into rows, for pickup with the bagger attachment. I try to go around and chop the leaves and blow them into rows for easier gathering!

Yeah I think your right Rusty. I have a old commet snapper with an 8ph that will do wheelies too...lol It will pull carts fine. Coarse its old old and I wasn't worried about it. I'll be pulling stuff like you do and maybe once in a blue moon with a little bit of dirt. I really trying to decide now if its worth the extra $700 to get the 17hp. I'm kinda leaning towards the 12.5 since I think the 17hp and 33" cut is overkill for me.

I installed an 8 hp engine on my smaller Snapper RER, and it does just as good a job as my 12 h.p. that is stuffed away in the back garage, until spring, when i will install a good engine on it for summer mowing! The original engine just refuses to start any more--completely worn out!