The crank sections are splined together, and 277° is just where it falls without cutting the crank apart and welding it back. The 360° was the most cost-effective crank and that's why Yamaha did it that way. It simplified ignition by firing both plugs at the same time every rotation, and made carb tuning very easy. 270(ish) just makes more power/torque so that's what we do. At great expense.
The XS lost THIS battle… but hands down wins the war. Forty year age difference in tec…. Take your pic.. 1) Complicated EFI and computers…and electrons running in and out of black holes …. You need a rocket scientist and three diagnostic computers… and a degree in rocket surgery. Or….. 2) two carbs a set of points and a condenser…. Oh… and a timing light and e feeler gauge for the valves. What was the result…. One or two seconds… I hope that you buy the new one…. And leave the nicer bikes for me ( us)
It sounds like a V8! Too bad the 256 cam couldn’t be rephased. They were THE best cam of the XS range. I s there a reason why the 256 can’t be rephased? They have longer rods.
Can you get 533 heavy duty cranks and the stuff to build 800cc+ rephase. Or are they just not around? Also the heavy duty transmission gears from the 750s etc. I would love to build a 840ish 277 with a 256 rephased cam and a 533 crank. Is that even possible. I wish Yamaha would make the best parts for this. 533 crank and rods, wide dog slider gears and the heavy duty kickstart gears. And a wide spread 3rd - 4th and an OD 5th. What is cool is I heard a guy riding a 750 cc long rod engine 277 decent pipes and BS38 carbs with some better gearing and he was just out walking the dog up and around relaxed the tach going up to 6500 but it wasn’t making a racket. It was a reground 256 cam like the one on my XS2 I had 40 years ago. It was a 360 degree, but they just had a relaxed beautiful ride. That’s what I want. How come the 533 crank wasn’t used in the US?
Is it a 270 or 277 ? It sounds like a V8 when it is on the power band. I have decided that round slides are wrong for the street. Rebuild a set of BS38s and it will rev so quickly in any kind of weather situation from a dead start . The rephrase really helps vibration, the rear view mirrors become useful. And they sound like a V8.
Man I miss my rebel.. my current vt500 ascot is an upgrade in pretty much every way but that rebel was so simple, reliable and easy to work on! Not one issue over the 20k miles I put on the thing.. just couldn't really handle highways.. I definitely took it on them, but often I found myself planning my routes around the bike. The vt will eat up any route I choose.
In the early nineties, I was a marine recruiter in Richmond, and bought seven basket case XS 650's, and one that had sat in the rain minus spark plugs. I swapped top ends from one basket, built the others and sold, and rode the one for three or four years, with great pleasure. I'd had a 64 TR6R five or six years in the late seventies, a half a dozen harley's, and now ride a 78 Bonnie, just recently bought. I'd never delved into the XS's I had, just swapped parts to put friends on bikes, but I'm really intrigued by this as it's so easy to do on these engines. Much as I hate to say it, this was what Triumph should've done going to the T-140, the engineering on the XS is simply up to date with it's times, and while quite solid, sound, is merely putting modern technology in a time tested, proven bike. I'm seriously considering building up a custom motorcycle around this engine. Thanks, it really sounds great.
I'm glad to see this, I've been riding since 1969, owned a dozen bikes in my youth, no batteries, couldn't afford them, and it's not that hard to set up a system that works like this. I'm glad to see technical support in making this common, I've run no battery bikes from an old "Sears, Allstate" 175 to Harleys of all sorts, including Triumphs, Ducati's and certainly XS 650's. I bought an 82 XS in the nineties, and seven or eight basket case XS's, built and sold them to keep one, well paid for and they are one of the easiest to make solid, sound, reliable, and cheap to run and keep. I've got three bikes now, and would welcome an XS into my shop eagerly. Thanks for sharing this, the bike looks and runs great.
Why did not Harley had this idea from factory ? I have a Sportster 2004 and a saw from the begining that the swingarm is very weak at this point. From 2005 model there is a huge different better solution. I like this idea..
