Yoshimura R&D Superbike

Here's a scanned copy of the Violence on the Racetrack article.

mtbspeedfreak wrote:

LarryC wrote: Probably ultra expensive and a total waste of money unless you plan on living at red line when you ride. They look so cool but way, way overkill for a street motor. Shim under bucket is a total pain in the ass when it comes to maintenance. There's really no good reason to run it on a small bore street motor. You don't need that much camshaft to have a really strong pulling engine.

Put the money toward a brand new rack of carburetors and avoid the pit falls of buying used ones.

If you've never ridden a really well prepared fast KZ, I'll tell you this, you can't even begin to compare the performance of a stock one to a built one and I'm talking about non radical components used inside the engine.

I sent an inquiry to Yosh R&D asking for prices on all of the Z1 Yoshimura swag. Who knows, maybe we'll be surprised!?!? [Yeah right...]

Good God... :pinch:

Retail
Steel straight cyclone 110-291-4640 $1270.00
ST-L2 Cam 211-291-S201 $1430.00
Cam Chain 222-999-1220 $195.00
Valve retainer, cotter, & valve soring set, flat groove
220-291-0000 $1225.00
Valve retainer, cotter, & valve soring set, flat groove
220-291-9000 $1225.00

I replied asking why some of the parts were $400 more expensive than Webike in Japan. Can't wait for their answer. :whistle:

How much does a pair of hot Web cams cost? A heavy duty Tsubaki cam chain sets me back $47.37 from APE. How much should a valvetrain set up (minus valves) cost?

Your paying for the name yoshimura on those parts,a motor doesnt pay attention to brand names! :woohoo:

wireman wrote: Your paying for the name yoshimura on those parts,a motor doesnt pay attention to brand names! :woohoo:

I definitely understand that. Does Web make hollow cams?

mtbspeedfreak wrote:

wireman wrote: Your paying for the name yoshimura on those parts,a motor doesnt pay attention to brand names! :woohoo:

I definitely understand that. Does Web make hollow cams?

Why do you think you need hollow cams?

Run a stock motor on a Superflow Chassis Dyno and then run it on a Dyno Jet.... You'll likely pick up 15 - 20HP without ever even adjusting a carburetor :lol:

:woohoo: :woohoo: :woohoo: :woohoo: :woohoo:

a nice set of solid web cams cost about $450.


a well built 10.25:1 1075cc, would have more power, than this yosh motor.

its sad to say, but these bikes, even built to 1200cc's, still dont have the power of a modern 600 sport bike. and unless u do the work to get massive ground clearance, u they get smoked in the corners by a 125.
my pals little ninja500 smokes my kz in the corners, because my cases hit.

i would love to follow a high end Yosh build thread, but i would also hate to see u spend all of that money and get no performance gain for the effort.

i sure would love to see this evolve into something that looked like a vinage racer, or a Sanctuary bike look.

this is just my opinion, please dont be offended by it.

mark1122 wrote: a nice set of solid web cams cost about $450.


a well built 10.25:1 1075cc, would have more power, than this yosh motor.

its sad to say, but these bikes, even built to 1200cc's, still dont have the power of a modern 600 sport bike. and unless u do the work to get massive ground clearance, u they get smoked in the corners by a 125.
my pals little ninja500 smokes my kz in the corners, because my cases hit.

i would love to follow a high end Yosh build thread, but i would also hate to see u spend all of that money and get no performance gain for the effort.

i sure would love to see this evolve into something that looked like a vinage racer, or a Sanctuary bike look.

this is just my opinion, please dont be offended by it.

mmm.... that's one area where i dont necessarily agree, i build my vintage racers to race with other vintage racers, not slug it out with modern 600's. what would be the point indeed?
if MTB wants to do vintage parade of track days on a tuned bike, why not. I think that the main point is that he is chasing hi-perfomrance with expensive means. he will end up with a short fuse of a motor that's also going to be quite hard to enjoy on an ocasional track day, unless your name is eddie lawson. To have fun on such a peaky motor you are going to need close ratio gearbox too and gear it according to each track to perfection. See why a torquer makes lots of sense also for your needs?

BTW, doing also chassis and suspension work means that you will not run out of ground clearance so fast, even with race compound 18"

In all honesty, I just don't want to see you spend money on things that will not return real value in performance.

A ported head, 1075 or 1015 kit, some mild cams and even stock 28mm carbs jetted properly will yank 25 -30 HP gain. Now that may not sound like a whole bunch but 25 HP increases can be felt in your ass without any question. The key element is doing that without breaking the bank, keeping it fully street reliable & easy to do maintenance on.

The more cam and carburetor you put to the mix relative to the size of the engine, the higher you have to rev it for satisfaction..... Very important to keep that in mind :side:

You need hollow cams like you need another testicle.

Price out good S.O.B. buckets and Ti Retainers.... there's at least half the cost of a pretty nice rack of brand new carburetors that are going to give you a definite, feel it in the seat acceleration improvement.

Joe Hooper has the best prices on pistons that I've seen if you're a retail buyer.

turboguzzi wrote:

mark1122 wrote:
and unless u do the work to get massive ground clearance, u can get smoked in the corners by a 125.
my pals little ninja500 smokes my kz in the corners, because my cases hit.

this is just my opinion, please dont be offended by it.

mmm.... that's one area where i dont necessarily agree, i build my vintage racers to race with other vintage racers, not slug it out with modern 600's. what would be the point indeed?
BTW, doing also chassis and suspension work means that you will not run out of ground clearance so fast, even with race compound 18"

Thats very true. i dont race vintage, so I wasn’t thinking along that line. I don’t think he will be racing either. It may make sense to learn to ride during track days first. i run trackdays twice a month, so i see a lot of dif bikes running together. I was merely pointing out the difference. a rooky on a vintage rocket can get beat easily, buy a modestly experienced rider on a small cc bike.
and yes u must do a good job on the setup to achieve proper ground clearance. that was my point.
i'm not sure what rim size he will end up with. that will be an important decision. will he be able to get street rubber for 18's ? not much point running race rubber for parade laps. Good modern sport tires r plenty sticky enough, but u sacrifice the ground clearance running 17" rims.
but it could be done with the proper suspension work. i'd rather see textra money spent on that area. those Sanctuary bikes run 17's. they must run longer forks and shocks.
i have a pic of lange hindel racing down a straight. it looks like his bike is JACKED UP BIG TIME.

If Im gonna spend that kind of time/money building a bike Im gonna take on anything/everything that comes my way,and when I lose to a little ol 600 at the track Im gonna be really pissed! :sick: :woohoo:
Thats why I race in a straight line ! :woohoo:

wireman wrote: If Im gonna spend that kind of time/money building a bike Im gonna take on anything/everything that comes my way,and when I lose to a little ol 600 at the track Im gonna be really pissed! :sick: :woohoo:
Thats why I race in a straight line ! :woohoo:

straight line racing does help even the field a bit. :laugh: