Torque peak

Didn't dyno the bike yet, this morning I adjusted camchain, checked cam timing(slightly advanced), set valves(.003/.006) compression tested (lots of compression, cold), static and dynamic timed ignition to stock marks, synced carbs(very easy with cvks), adjusted the chain, set the tire pressure and hit the local hills with a friend on a vstar once it warmed up outside. I kept it in 4th and pulled one of our local grades and just pushed past the vibes and revved the snot out of it. The 1300 walked by me but that's not surprising. Still, I managed to keep 95-105 mph up a really long straight pull. I revved it until the clutch started to slip, it sounded like heaven. It has got some impressive power up in the rev range, but lots of vibes. I think all is right in the world. I'm probably just being unfair to the old girl. My last bike was a vstar 1100 that didn't vibrate hardly at all, and the common crankpin design of the v twin means no rocking couple effect. My other current bike is a GT1000 ducati, and it's well engineered and very refined, same common crankpin principle there. I must just be a common crankpin fan.

Hope you all had a good holiday, thanks for your input.
 
The 2nd oversize were lighter by feel. I didn't weigh them mikes xs says 453 grams. I didn't have the crank rebalanced unless Hugh does that along with the rephase. From everything I read, I didn't think it was necessary unless one of the pistons weighed a different amount than the partner. What's your thinking behind the inquiry?
 
Rear tires come in many diameters, but with an Avon AM23 rear an 18 - 30 gearing would give you about 137 (!) mph @ 8000 rpm. I strongly suggest you lower the gearing. With, for example, 18 - 33, the bike will accelerate harder and still be (theoretically) capable of reaching 125 mph while maintaining a reasonably relaxed cruising rpm. It's almost like free horsepower with no reliability downside.
 
650performance said:
Rear tires come in many diameters, but with an Avon AM23 rear an 18 - 30 gearing would give you about 137 (!) mph @ 8000 rpm. I strongly suggest you lower the gearing. With, for example, 18 - 33, the bike will accelerate harder and still be (theoretically) capable of reaching 125 mph while maintaining a reasonably relaxed cruising rpm. It's almost like free horsepower with no reliability downside.
Click to expand...

Oh sure, most of our bikes will do 125 mph, and 137 to 140 mph on a good day
:laughing::laughing:

Strap some wings on and they would be able to fly:doh:
 
I run 18/33 gearing, my top speed over the quarter is 115 in 4th, so as a top speed would say more than capable of 125
 
I think it's about time the card was tossed in here. The ORIGINAL (1987) Kawasaki EX500 made 59 Hp out of the box, weighed 400 pounds, and would tick off a 1/4 mile in about 13 flat at 102 mph. Top speed with a 6 speed transmission was just under 120 MPH.

Unless you are shitting out 70-plus ponies and dumped upwards of 75 pounds off your XS, No Fucking Way.

http://www.biker.net/roadtest/tx650a/650a5.jpg

Point of reference, you are quoting performance on par with (and BEYOND) the SV650. I own one, and had an EX500 prior to the SV, and I can tell you that either one will eat a stock XS's ass up.

http://www.sportrider.com/sportbike-riding/great-sportbikes-past-1999-present-suzuki-sv650
 

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Actually says 114 http://www.sprinting.org.uk/images/results/WZ290614.pdf look at 13d jason winterson, 13d has 2 xs's running in it, if you look at the extra runs you'll see one run at 12.43 and another at 12.49 the big difference between my bike and the other xs is about 65lbs of rider weight
at 16.40 in this video is me
at 1.30 is me
bike in the left lane is a cbr600
 
yamahammer said:
The 2nd oversize were lighter by feel. I didn't weigh them mikes xs says 453 grams. I didn't have the crank rebalanced unless Hugh does that along with the rephase. From everything I read, I didn't think it was necessary unless one of the pistons weighed a different amount than the partner. What's your thinking behind the inquiry?
Click to expand...

I intend to go down a similar route to you (but don't hold your breath!) so the statement you made in your initial post 'and starts to vibrate more than is tolerable' is of some concern.
High vibration is not something I recall reading about with the re-aligned crank so I was wondering if the different weight of pistons had altered the balance factor sufficiently to cause your issue.
 
Max Midnight said:
I intend to go down a similar route to you (but don't hold your breath!) so the statement you made in your initial post 'and starts to vibrate more than is tolerable' is of some concern.
High vibration is not something I recall reading about with the re-aligned crank so I was wondering if the different weight of pistons had altered the balance factor sufficiently to cause your issue.
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Maybe someone tried to balance my crank before I got the bike, as a 360. If that happened it may not have been obvious to me or Hugh, that was the first one I'd seen. I've read that heavier pistons normally have a beneficial effect on the rephased balance factor but if my crank was altered from stock at some point it could be that my crank isn't ideal for heavier pistons.

Some other factors that may be contributing to my vibration, worn out riser bushings (cheap to replace, might as well), NOS magura scrambler bars (no bar end weights, also easy to try a set of stock bars with stock weights).

If you're thinking about doing the rephase, I definitely still recommend it. I'll figure this nuisance out sooner or later, and the roar through the pipes is worth it all over again :thumbsup:
 
jay760 said:
Actually says 114 http://www.sprinting.org.uk/images/results/WZ290614.pdf look at 13d jason winterson, 13d has 2 xs's running in it, if you look at the extra runs you'll see one run at 12.43 and another at 12.49 the big difference between my bike and the other xs is about 65lbs of rider weight
at 16.40 in this video is me
at 1.30 is me
bike in the left lane is a cbr600
Click to expand...
Jay, I just watched some of those sprinting vids, you guys are flying on those xs650/707/750's whatever they are. Impressive, regardless of what you had to do to that old engine.
 
So the consensus is they have shown up in 256 cranks, right? This is a 447 crank, but it sure as hell would vibrate if only one cylinder was altered (one flywheel replaced for who knows what reason lost to the sands of time)... Maybe I'm the luckky owner of 256 flywheels and 447 rods. Frankencrank haha.

Maybe I'll split the cases this winter and find out, it's weeping a bit anyway.
 
jay760 said:
Actually says 114 http://www.sprinting.org.uk/images/results/WZ290614.pdf look at 13d jason winterson, 13d has 2 xs's running in it, if you look at the extra runs you'll see one run at 12.43 and another at 12.49 the big difference between my bike and the other xs is about 65lbs of rider weight
at 16.40 in this video is me
at 1.30 is me
bike in the left lane is a cbr600
Click to expand...

You forgot to mention that your bike is nowhere NEAR street stock. It's a drag racing bike. Street stock, not even anywhere close to that.:thumbsup:
 
I wouldn't have mentioned my bike if we were talking standard xs's and in agreement with 650perfomances statement, but we are talking about a rephased 750, which should be more than capable of a good top speed,

Frame is standard as is the swing arm on mine, the engine was slapped together, it would make most engine builders cringe, bought the complete top end off ebay for about $200 just put some Wiseco pistons in, not bored to suit, ignition isn't timed, it's somewhere about there and the carbs only went on that morning and weren't jetted to suit, they were running rich with a hesitation between gear changes, so would be capable of a lot more.
The only thing that cost any real money is the electrex world ignition, even that was cheap up to some other systems, this is a budget bike in every sense, just goes to show what you can do with limited tools and resources.
 
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