I am looking for an engine for my bike. Here are my requirements: 1) Can't be too loud 2) Engine must last at least 2-3 years (twice-a-week use, no more than 20 miles at a time). 3) Must travel around 25 - 35 MPH 4) Must be removable (In around a 2-3 hour time frame) I have been looking online, and recently I came across the DAX offer for a Tanaka PF3300 engine and a standard friction drive for $320. The standard HT engines are all around $220. Is the Tanaka PF3300 worth $100 extra? Are the friction-drive mounts (DAX) any good? Do the engines stick out of the side alot? Can I buy an additional gas tank for the Tanaka kit? OR is the HT kit better. (Will it stand up to around 2-3 years). How much louder is the HT kits than the tanaka. This is my first build so please give me some guidance. thanks!