Author Topic: building a k2 to race  (Read 2284 times)

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Offline Curtis750

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building a k2 to race
« on: November 23, 2011, 05:52:09 PM »
Into the vintage racing with my yamaha 250 two stroke, was going to use my k2 as a daily driver, but now thinking I want to run a different class next season.

What all would you gurus do to make it race ready? I will be doing my own fiber glass tank and seat, and lightening everything I can, I have an 810 kit on the way, any head work?

What do you thinik

Offline Old Scrambler

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Re: building a k2 to race
« Reply #1 on: November 23, 2011, 06:19:31 PM »
Tell us what racing series or club you will be competing in.  Also tell us what the class is for your bike. With the over-bore its likely to be in the liter group so you will need a lot of head work. Take a look around this page and check out the popular vendors........all are considered reliable and offer free advice.
Dennis in Wisconsin
'64 Triumph Cub & '74 Honda CB750 Bonneville Salt Flats AMA Record Holder (6)
CB750 Classic Bonneville Racer thread - http://forums.sohc4.net/index.php/topic,135473.0.html
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Offline Curtis750

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Re: building a k2 to race
« Reply #2 on: November 24, 2011, 05:16:36 AM »
Hi there,

It will be racing in the VRRA in the class P2 Heavy, I will be going against:

H1,H2,H1r,H2r,750/850 Nortons,Big Ducati twins........ect
bumps up to P3 middle kawi 750fours,gs750fours,H1,H1r.....ect

There are two or three sohc 750's running.

It does not bump me into the liter class, the bike runs great in stock form now, i am half debating to leave the motor almost stock form for the first season, it will be a big transition going from a 210 pound 2 stroke race bike to a bike that is more then twice its size and a four stroke...

Offline Old Scrambler

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Re: building a k2 to race
« Reply #3 on: November 25, 2011, 10:44:33 AM »
The experienced folks on these pages seem to all agree on chasis set-up for best handling / braking issues first.........then get the motor up to speed.  Budget items for the motor would include mild intake porting, an F-2 or mild street cam.........mild decking for improved compression (maybe F1-2, K7-8 pistons), spin-on oil filter with cooler, adjustable timing, and best electrics.

If your set on boring the cylinder for the 815cc kit, you may want to send the head to MReick for porting, get some larger carbs, get the best exhaust, and spend money on a performance cam, the cam-chain system, intake valves, and and the valve-springs and keepers.

Assuming your motor is in good shape, the bottom end should be OK until you really start to go for higher compression and longer running times.  Lots and lots of discussion on current electronic ignitions.......
Dennis in Wisconsin
'64 Triumph Cub & '74 Honda CB750 Bonneville Salt Flats AMA Record Holder (6)
CB750 Classic Bonneville Racer thread - http://forums.sohc4.net/index.php/topic,135473.0.html
'63 CL72 Project(s)
'66 CL77 Red
'67 Triumph T100C
'73 750K3 Owned since New
'77 750F2 Cafe Project
2020 ROYAL ENFIELD Himalayan

Offline bwaller

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Re: building a k2 to race
« Reply #4 on: November 25, 2011, 12:24:19 PM »
Curtis, check the rules first. I believe you're allowed a 5% overbore.

Offline Curtis750

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Re: building a k2 to race
« Reply #5 on: November 26, 2011, 12:10:58 PM »
Yep, I found out that I can only go 5% overbore.

So the plan of attack now is to do some decent porting, a good cam, and have the best working pipe i can get.

Chassis will be braced, will be upgrading to a twin disc front end (drilled of course) and i may (may being the key word) have a lead on a twin leading rear drum.

Spin on oil filter kit is on deck, as well an oil cooler. Not sure what I am doing for timing yet

Offline Curtis750

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Re: building a k2 to race
« Reply #6 on: November 26, 2011, 12:16:46 PM »
This is were i am sitting now


Offline Old Scrambler

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Re: building a k2 to race
« Reply #7 on: November 26, 2011, 06:48:48 PM »
That's 5% over 750..........you only have 736...................don't forget the shocks and check on fork swaps........maybe you could go to early GL1000 forks...........anyhow, check out the emulators...............and get the best bars for your class.............set-back pegs?
Dennis in Wisconsin
'64 Triumph Cub & '74 Honda CB750 Bonneville Salt Flats AMA Record Holder (6)
CB750 Classic Bonneville Racer thread - http://forums.sohc4.net/index.php/topic,135473.0.html
'63 CL72 Project(s)
'66 CL77 Red
'67 Triumph T100C
'73 750K3 Owned since New
'77 750F2 Cafe Project
2020 ROYAL ENFIELD Himalayan

Offline Curtis750

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Re: building a k2 to race
« Reply #8 on: November 26, 2011, 07:03:18 PM »
Shocks and forks will be coming into the spring when some more money comes in, would rather do suspension and motor right the first time.

Clip ons are staying and yes there will be rear sets, not sure which ones yet though.. more then likely tarozzi's by fast from the past, i have had good luck with them before.

My small cafe fairing is now boxed up and ready to send out the door in exchange for an actual racing fairing, it should arrive around the first or second week of jan. perfect timing to finish the rest of the body work

Offline voxonda

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Re: building a k2 to race
« Reply #9 on: November 27, 2011, 09:37:29 AM »
Interesting thread, like to see what you come up with.

Rob
Better sorry for failing then for the lack of trying.

Offline Curtis750

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Re: building a k2 to race
« Reply #10 on: November 27, 2011, 07:11:56 PM »
Thank you,






And I just ordered this



Hopefully more parts will show up soon :)