ideas to make some POWER

[bwringer]

... but hanging with the crotch rockets is a loosing proposition.

No, it's not a losing proposition. See above.

Get your bike in decent shape, and work on your skills. Unless you're descending into numptydom and simply "racing" stoplight to stoplight, you CAN and WILL keep up and leave the crotch rocketeers far behind riding your GS650.

On bikes, operator skill makes a much larger difference than it does in cars. On a road course or winding road, Jeff Gordon in a rusty '83 Corolla could never beat your average orthodontist in a new Corvette.

But in the world of bikes, the exact opposite is true. Loris Capirossi riding a 1963 Tohatsu Runpet would easily outpace the average unskilled sportbike rider on a new R1 (again, assuming curves are involved).

 

[Guest]

. Loris Capirossi riding a 1963 Tohatsu Runpet would easily outpace the average unskilled sportbike rider on a new R1 (again, assuming curves are involved).

I dig some of the vintage bikes, and immediately checked out my trusty motorcycle specs site http://www.motorcyclespecs.co.za/Index.htm to see what an R1 beating Runpet looks like, only to find no listing...probably super-rare eh?

Tony.

 

[bwringer]

I dig some of the vintage bikes, and immediately checked out my trusty motorcycle specs site http://www.motorcyclespecs.co.za/Index.htm to see what an R1 beating Runpet looks like, only to find no listing...probably super-rare eh?

Tony.

Here's a Tohatsu Runpet GP racer -- 11 stampeding horses! :mrgreen:
http://www.micapeak.com/HMarc/misc/tohatsu.html

Another fire-breathing Tohatsu Runpet:
http://www.lump-proof.com/CLASSIC/CRAFT/NC/runpet/index.html

I saw a reference to a Tohatsu Runpet in a magazine long ago, and I thought it was just something someone had made up to be a low-power laughingstock. But I did a little digging and found out that the Runpet was real. Still low power, but perhaps not a laughinstock.

 

[Guest]

Cool bike...thanks! 11+ bhp isn't too shabby from only 50 c.c if you think about it...a lot more h.p/c.c than an 1100E...or even a new Gixxer 1000!8-[
Okay...back to the GS650 power quest.

Tony.

 

[49er]

Now here's the hard part: get the engine and carburetion back to bone stock (richen the idle mixture screws slightly), then LEAVE THE ENGINE ALONE. This means new o-rings for the carbs, seal the airbox, make sure the air filter is correct, and probably new engine/carb and carb/airbox intake boots. Set the float height very slightly rich, then fine-tune to achieve the smoothest possible transition from idle to 2,000 rpm.

You see, once the road begins to curve, Big Speed is not found at wide open throttle -- the secret is smoothness at low rpm, when you're just getting back into the throttle in a turn. The sooner and the smoother you can open the throttle, the faster you'll be. The amount of power matters only to goons who can only wobble through the turns then yank the wires open.

Brian
I agree whole heartly with your
handling and braking improvement strategies and the huge benefits to be gained by this approach.
However, to claim that 99% of a riders speed can be attributed to his ability is a bit over the top.
I would put it more like this. If two riders had identically prepared machines (which is impossible to achieve anyway) and neither of them had ridden those bikes previously, the one who had honed his cornering and braking skills would always prevail over the other.
As for leaving the engine and carbs stock, I agree that in many cases this is the best idea.
However, tuners who have experimented with many performance parameters eventually reach a point where they go broke or finally work out what works and what don't. The ones that stick with it realise that they have to balance the mods to achieve the levels of reliablity, tractability and performance they desire.
My 850 is a case in point! The PO had left everthing stock except the Cycle Works 4-1 pipe and some minor jetting/needle position changes. I decided to increase the capacity and the CR and leave everthing else stock. The stock squish area and piston weights were retained to keep a balance to the mods. I slightly richened the pilot circuits and that was it. An electronic ignition was fitted to improve the whole power curve.
My point is this. I haven't dramatically changed the top or bottom end performance. I've just made the lower,middle and lower top end ranges that much stronger. These are the exact ares that I was seeking to enhance.
So, all street modifications should be kept well in balance. That's why we can still beat some of the pocket rockets. Their stock state of tune tends to be peaky. With their weight distribution well forward, they don't turn into corners as well balanced as ours, under hard braking.