CBR600 F2 jetting for track?

[nzspokes]

Building up a CBR600 F2 for track. Anybody remember from back in the day if they needed a re-jet for a K&N and race can?

Thing is in bits so easy to change jets now rather than later.

[Grumph]

Building up a CBR600 F2 for track. Anybody remember from back in the day if they needed a re-jet for a K&N and race can?

Thing is in bits so easy to change jets now rather than later.

The two I've been involved with - one when they were new, one now in pre 89 - have needed no jetting changes at all.

The one back in the day, after building the motor with more sensible bearing clearances and finishing the oil holes in the crank properly, was very quick indeed.
It also made the transition later to a road bike and lasted very well. Probably carburetted better than stock with no jet changes...

[nzspokes]

The two I've been involved with - one when they were new, one now in pre 89 - have needed no jetting changes at all.

The one back in the day, after building the motor with more sensible bearing clearances and finishing the oil holes in the crank properly, was very quick indeed.
It also made the transition later to a road bike and lasted very well. Probably carburetted better than stock with no jet changes...

Cool, I like the sound of that.

This old girl has been on the track at some time as its drilled for lock wires. Looks like somebody had a slide as the block has been welded to refit the oil cooler. Seems well done so not bothered.

Did you do much to the suspension on them?

[Grumph]

Cool, I like the sound of that.

This old girl has been on the track at some time as its drilled for lock wires. Looks like somebody had a slide as the block has been welded to refit the oil cooler. Seems well done so not bothered.

Did you do much to the suspension on them?

At the time,no, regs didn't allow it. The current one is not satisfactory as i've told the owner. He's got a shock from something which at least holds the back end up but not much more. Despite this he's pretty quick on it. Given the current pre 89 regs, if I was asked to do one now, serious like...I'd put it in a 400 chassis as was popular early 90's.

[nzspokes]

At the time,no, regs didn't allow it. The current one is not satisfactory as i've told the owner. He's got a shock from something which at least holds the back end up but not much more. Despite this he's pretty quick on it. Given the current pre 89 regs, if I was asked to do one now, serious like...I'd put it in a 400 chassis as was popular early 90's.

Righto. Its just gunna be a track day bike, not a racer.

Yeah the steel frame on them are a bit porky.

[Icemaestro]

Good choice, I love the old cbr600's. Manual cam chain tensioner if it hasn't already been done, I had a shock from the later F3 or even better would be the F4 - they had remote reservoirs on them...you can get nitrons etc as well but all depends on the money you want to spend. Is it the earlier or late f2 model front forks? (IE do they have cartridge forks with the damping adjustment in the middle? or old style fork?)

if you wanted to go nuts you could look at bits from the F3/F4 with the carbs/airbox - I think they were ram air from memory?

[nzspokes]

Good choice, I love the old cbr600's. Manual cam chain tensioner if it hasn't already been done, I had a shock from the later F3 or even better would be the F4 - they had remote reservoirs on them...you can get nitrons etc as well but all depends on the money you want to spend. Is it the earlier or late f2 model front forks? (IE do they have cartridge forks with the damping adjustment in the middle? or old style fork?)

if you wanted to go nuts you could look at bits from the F3/F4 with the carbs/airbox - I think they were ram air from memory?

My understanding is a later shocks are a bit longer? Which is a good thing. Early forks but getting some VTR forks to rob the carts out of them.

Tiz a budget build so no Nitron for this bike.

[Icemaestro]

the F4 shock was longer, yes, and had to be cable tied to the subframe. you can compensate with another longer side stand, but I didn't and it was all right...just be a bit careful on slopes!
The second F2/3 build I used a F3 shock and had it reconditioned for about 200$ from a guy down in henderson

[nzspokes]

the F4 shock was longer, yes, and had to be cable tied to the subframe. you can compensate with another longer side stand, but I didn't and it was all right...just be a bit careful on slopes!
The second F2/3 build I used a F3 shock and had it reconditioned for about 200$ from a guy down in henderson

Stand is the least of the problems. Want to get weight out of it, so will drop the stock gauges etc. Need to work out a rev counter for it I guess.

[Grumph]

Stand is the least of the problems. Want to get weight out of it, so will drop the stock gauges etc. Need to work out a rev counter for it I guess.

Pull the stock tacho out of the gauge cluster and mount it on it's own. They were one of the lighter 600's when they came out. Lighter cosmetics help a bit.

[BuzzardNZ]

Yeah the steel frame on them are a bit porky.

Is that kind of like how some dogs look like their owners?

[nzspokes]

Is that kind of like how some dogs look like their owners?

Go wash ya grubby bike.

[scracha]

The two I've been involved with - one when they were new, one now in pre 89 - have needed no jetting changes at all.


A CBR600F2 in pre89 is about as legit as a ZZR600 in pre89

Roger Calthro and Aaron Carr were thrashing CBR600F2's in the post 90s carbies class at the VMCC....might pay to ask them about mods.

[Grumph]

A CBR600F2 in pre89 is about as legit as a ZZR600 in pre89

Roger Calthro and Aaron Carr were thrashing CBR600F2's in the post 90s carbies class at the VMCC....might pay to ask them about mods.

You're right of course. Slip of the memory, CBR600F is what i was referring to. From what i've seen though, the advice should still hold good.

[nzspokes]

You're right of course. Slip of the memory, CBR600F is what i was referring to. From what i've seen though, the advice should still hold good.

Not sure but its the same motor? It wont be raced just a track day bike.

[F5 Dave]

Its amazing what weight can be stripped off bikes when you decide its a one way never back to road path. Seat unit will pay big dividends in weight and better riding feel than a tall squeegy road seat.

[scracha]

Not sure but its the same motor? It wont be raced just a track day bike.

Nah...totally different motor. Even the F1 had 2 different flavours (different cams, carbs and supposedly extra 5bhp).


Gearbox was so bad as my F1 that the shift star pro was worth about 0.5s a lap.
http://www.factorypro.com/Prod_Pages/prodh09.html