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PaulB2 · 06-16-2015, 08:16 PM

It strikes me how close to the perfect recipe the old Brit AJS and Matchless thumpers were (350 and 500 cc lonnng-stroke singles). The Royal Enfield Bullet has a 70mm bore for the 350 and 84mm for the 500, both engines have a 90mm stroke (I don't know if this still applies to the new unit construction engine). I think the 350 Bullet would be about the ideal bike for a high mpg gas motorcycle. Now I wonder how to get my hands on one. Buy a 500 and import a cylinder and piston, and swap it out?

(later)
Woops, the Yam XV250 also is undersquare, bore 49mm, stroke 66mm. And it does better than anything on fuelly in the 250 class and up, as far as I can tell. The cruiser style and low seat probably keeps the rider out of the wind better.

06-16-2015, 08:16 PM	#47 (permalink)
PaulB2 EcoModding Apprentice Join Date: May 2011 Location: Oregon Posts: 106 Thanks: 0 Thanked 26 Times in 22 Posts	It strikes me how close to the perfect recipe the old Brit AJS and Matchless thumpers were (350 and 500 cc lonnng-stroke singles). The Royal Enfield Bullet has a 70mm bore for the 350 and 84mm for the 500, both engines have a 90mm stroke (I don't know if this still applies to the new unit construction engine). I think the 350 Bullet would be about the ideal bike for a high mpg gas motorcycle. Now I wonder how to get my hands on one. Buy a 500 and import a cylinder and piston, and swap it out? (later) Woops, the Yam XV250 also is undersquare, bore 49mm, stroke 66mm. And it does better than anything on fuelly in the 250 class and up, as far as I can tell. The cruiser style and low seat probably keeps the rider out of the wind better. __________________ Last edited by PaulB2; 06-16-2015 at 08:22 PM..