rebuild?

If you started off with a decent 4 - 5 - or 6 Hp motor but now its getting tired and worn is it more cost effective to buy a NEW motor rather than rebuild the old one ? Is it even worth the time rebuilding if the cost were the same?

I have an old 4hp Briggs I pirated off of a $20 garage sale Monkey Wards Tiller, I attempted to get it to run before I pulled it, but no luck. It seems low on compression, and weak to no spark. it appears to be a #100202 built in 1965 I havent torn it completly down yet, but I did pull the...