Have you treated your XS to a victory lately?

[headcase]

Not sure if this is the right category for this one. If not, I shall adjust it accordingly.
How many of you have challenged or been challenged by a bike and rider to a race...at the track or just for fun on a backroad? And how did you do? I hear more and more about how quick our 650's are compared to much larger and supposedly meaner bikes. So far I have only had 3 dares, and I've managed to spank all 3. And they were bikes I thought would suck my headlight out. This is getting more fun by the week, and I just wonder if it's been pure luck, or are the cojones for real? Let's hear some stories, and don't be afraid to brag..you're amongst family here.
So far:
Suzuki Volusia 800(?)
Honda VTX 1300
Honda Shadow 1100
...more to come, hopefully....

[XS Rod]

I was quizzing Shell Thuet one day when i was dropping off or picking up some parts and he was in a patient, chatty mood for the green kid asking, no doubt, dumb questions... what he told me when I kept asking about performance factors was ... and I quote... "you don't understand, this is a race motor". I'm forgetting Dan, is your motor stock or? Back in the day I had no problem spanking stage 1 Honda 750's... but to be honest there were bikes i steered clear of, Kawasaki 900's I considered to be a threat... and the triple two strokes like the Kawa 750 I always considered that to be a fairly violent machine.

[headcase]

Yep Rod, it's original 18k stuff inside and out as far as I know. With the exception of the usual...cam chain guide, gaskets etc and some bolt on bits outside. I did go with decent air filters and electronic ignition and I never ran it with the stock airbox. It came in a pile of other parts with the bike, and was incomplete anyways. I haven't had another street bike before to compare the performance to (71 Kawi 250 Samurai A1, but it never ran while I had it). I can see where it would be considered a race motor out of the box though..roller bearings all over, real light on the rotating mass etc. I'm not out to race the thing all the time. As it is, 60 is pushing it with the air and steering issues. But I do like to crack it open to that point occasionally, and was just surprised by the results and comments from the other bike owners. And I DO love a sleeper, so call me a satisfied customer so far.

[grizld1]

Headcase, the riders who challenged you should have known better--those machines are low-powered heavy cruisers, slow out of the hole. And I think you misunderstood Rod's quote from Shell; he meant that you can't compare the results of full-race mods to what you can do to the motor and still have it reasonably rideable and reliable on the street.

At the rear wheel, the stock XS650 motor puts a bit less power to the ground than the venerable Kawasaki EX500 air-cooled vertical twin, which would have given you quite a run; that 50 hp rating for the XS was measured at the crank on the bench, with no electrics or power train installed, and as we used to say back in the day, those Japanese horses were a bit on the small side. In today's environment the Suzuki SV650 twin is considered mildly tuned, putting out around 70 hp at the wheel out of the box. That's just about the limit for the old XS at 750 cc's and full-race mods, except for drag bikes that don't have to go far; if you tune for more, the cases start to break up under the load.

But I don't mean to be throwing a wet blanket here--you're having fun with your machine, and that's the important thing!

[headcase]

Not at all, sir. Thanks for clarifying. If I had done time on other street bikes in the past, I'm sure I would be able to put a lot more about these bikes in the correct perspective. I have mostly an automotive past where engines are concerned, so I suppose my point of view is skewed a bit that way...bearing inserts vs. rollers, 2 cylinders vs. 6 or 8, water vs. air-cooled. Not to mention handling characteristics vs. 4-wheels. The hp rating I can relate to. Same thing as net vs. gross with cars.
As far as going gonzo with mods, I'll treat this mode of transportation the same as I do my others, should I get into the engine. Probably go more for efficiency and durability instead of seeing how far I can push it until it sprays shrapnel on the pavement. I haven't grenaded one yet, in 30 years of driving and tinkering. Besides...how much horsepower do we humans really NEED on 2 wheels?
You may need to remind me of the above statement next winter when I get back into it for more fixes. I may have a tough time keeping the carbide burs away from the head, and with no water jacket to trespass into.....heheheheee!

[grizld1]

Before you go crazy with the angle grinder, follow the link at 650 Central and order Craig Weeks' engine modification guide. Also have a read through Jack's stickied thread on porting at XS650 Garage. Hogging out the ports on these motors is guaranteed to kill velocity and impair flow.

Don't get me wrong, I'm not opposed to performance mods; my own XS is punched out to 700 cc., ported, cammed, and fitted with Mikuni TM36/68 4-stroke pumper carbs. It's still in what I'd consider a fairly mild state of tune, but lively enough to be satisfying: with 17/32 gearing it'll redline in 5th, and it has a suspension that keeps it planted while that's happening.

As far as how much horsepower a human needs, I guess it depends on the human. I know that I wouldn't fool with motor mods on my SV650; on the backroads it can put as much to the pavement as I can control as it is, and more ponies wouldn't make me any faster.

[headcase]

No worries there, in a former life I ran the cylinder head dept at a place here in the Detroilet area that was to GM what Roush is to Ford. I noticed the ports on the 650 are plenty big volume-wise, my tweaks would be to valves, guides, chambers, and seat/bowl area...and of course some pretty polishing just to finish off the rest. I've been having visions lately of bribing the owner into letting me plop the head onto the beast flowbench there, just for curiosity's sake. I love doing before and after tests.
50 hp is plenty fine with me, but as with most things there is usually room for improvement from what the factory hands you. I'm thinking fuel mileage and upgrades etc. Why not shoot for 60 or 70 mpg? Driveability and response would most likely be even better than it is already. I'll check out the link too, thanks.
Is there anyone here that's done any 1/4 mile runs with their 650's? I'm more interested in the stock or mild versions, although anything would be interesting. I thought there would be a lot of 'war stories' posted already, but maybe we can make our own (evil grin)

[XS Rod]

Got my share of tickets, but nothing too exciting. Learned the hard way to pay my speeding tickets... and on one occassion was thanked for stopping. Was sitting at an intersection on the main street of this little town I used to live in. The light turned green and I just cracked the throttle... the front wheel came up a bit... thru the intersection and just prior to the quick left I happened to notice the lights. I figured I was awful close to home and if I was going to pay any owed restitution with my time, I definitely preferred my bike to wait for me at home. I cracked it down the street like I didn't know he was there and pulled over in my front yard. He was rather polite, thanked me for stopping... I had to stand there and did actually wait for him... I paid that one ... or??? Turn around please.. click click... don't bump your head... but that's another story... 442.

[grizld1]

War stories, headcase? OK. Bear in mind that on two wheels, stoplight-to-stoplight street drags are all about power-to-weight ratio and hookup; if you can't get it to the ground, you may as well not have it. Back in '79 I returned to the States after a few years in the Middle East, and discovered that nobody thought he had a real motorcycle unless it had 4 cylinders and a liter or so of displacement. That looked like gross overkill to me, so I decided to put something together that would make a point--a stiffened 175 Bultaco Mercurio frame with a fresh, professionally tuned, single-cylinder 360 cc. Bultaco Pursang motocross engine in it, complete with competition expansion chamber, just a straight-through fiberglass can on the stinger to deaden the noise a little. It was light, tight, and nasty, and made KZ900 riders cry on short runs; they'd pass it before a full quarter mile was reached, of course, but in eighth mile runs it slaughtered them.

[headcase]

Now there's a blast from the past I haven't heard in ages. When I was into dirt (80's), all I heard people blabbing about were YZ's, RM's, Elsinores, KZ's etc. Only one person mentioned Bultacos, and though I never got to ride one, I was told they were rather vicious. Exotic stuff for us smalltown dirt munchers. I had a converted '74 KS Kawi 125. It was a snotty low rpm grunt, with not much suspension so it couldn't keep up with the new stuff at the time, but it sure did like to climb trees, much to my dismay.
Then there's the Uncles modded absolutely satanic 70's Husqvarna 400. Left-side kick lever. I watched it spit him over the trailer he stood on to start it. So loud a headache was mandatory while dialing it in idling. So finicky it refused to run unless the filter was spotless. So much torque it was almost unrideable. I tried it one time only, and when the front wheel pointed at the sky in 4th on dry pavement, I surrendered and idled it back home. If I say more, I will have nightmares.
Oh well, I was hoping for XS stories, but 2 wheels is 2 wheels. It's all fun in my book

[grizld1]

OK, here's one for ya: 4 riders, all with 30-plus year of riding, 2 with Pro-Am racing experience; 4 bikes: a Hyabusa, a big Triumph power cruiser, my '03 SV650, and my '77 D-model; scene: the Missouri Ozarks, mix of switchbacks and sweepers. The Yamaha at that time was lightened a bit, with suspension sorted nicely, and VM carbs and 1.5" 2-2 exhaust system with glasspack megaphones on a stock motor.

The Trunch, of course, was hopeless--couldn't be heeled over very far before grounding, and there was nowhere to use the power. Our former racers led on the Busa and the Yam; I hung back on the Zook and observed.

The Busa was handicapped by its long wheelbase and slow handling, but it had sufficient ground clearance and was agile and well-ridden enough for its power to be used out of the corners--and at the next corner the old D would catch it, every time. At the first stop, the Busa rider walked up to the Yamaha and just stared at it. I said, "See something wrong?" Answer: "That thing's amazing. I never thought it'd keep up."

[headcase]

Now we're cookin. I love a good underdog story. And I KNOW there's more. Bring it!