Topic: Pragmatic about carbs

[Greg H]

OK. Guys . Recently I posted about fitting a pair of Weber DCOEs onto my bike . Well before I dive in and spend the money, I've been doing a bit of research on the old tinternet and as a result I'm considering adopting a much more pragmatic approach to the choice of carbs. I read somewhere that Dale Walker had run some good times/speeds back in the day on his sohc Honda, running bored out 29 mil Mikuni Smoothbores. I used to run bored out stock carbs on my old 970 with good results, so the fact that a "normal" carb set up won't look as trick as the Webers doesnt concern me , I just want the motor to make good power and for the bike to perform like a good mid 70s P/stock bike should perform .
So what do you reckon guys ? Am I barking up the wrong tree ? , would you stick with the Webers ,or is fitting a set of bored Mikunis a good way to go ?. Thanks in advance , Greg "H".

[754]

Why bore when you can pullem out and change them?
Went too big on the boring..works good on the strip but cant live with it on the street? What to do ?

Never a problem with Webers.. Stock looking carbs.. Look better for a sleeper..though..

[joe p]

I had a set of K2 carb bored out on a 900cc SOHC and ran 10.65 in 1/4. I was about 210lbs back then

[gschuld]

Joe P.

      Thanks for sharing.  Your 10.65 in the 1/4 on bored factory K2 bars on a 900cc motor, what kind of bike/class were you running?  Was it a factory frame bike or a dragster.  The reason I am asking is that the weight difference between a 24lb framed dragster with a race weight of a little over 300lbs and a factory frame/swingarm bike at 450lbs plus makes a big difference when trying to assess what kind of overall power you were making to get to that 10.65.  Regardless, that is impressive for bored factory carbs.  These were the carbs that Frank has now? 

George

[Greg H]

Seeing as this post popped up again , just a quick update . I've decided to bite the bullet and (when I've decided on the precise engine spec) to invest in a set of new Kiehin CRs . I've been doing a lot of research on carbs and have concluded that a set of new Kiehins will fullfill my build criterea , and these are , to look period , and to provide me with more power and less hassle than a set of old carbs . 

[scottly]

Greg, what is the cost of the new Kiehin CRs? How does it compare to a set of new Webers? (The new Webs are about $800 US for the pair last time I checked)

[Jerry Rxman Griffin aka MuthaF'er]

About the same Scottly. How readily available are the Weber manifolds? You have me thinking about the eventual 1000 

I have a new set of CR31's for the 900 for exactly the same reason Greg said. Plug and play. Sudco will even set up some CR33's if you want.

[POPS 911]

That 10.65 on a 900cc bike with a 210 lb. rider is best number for that set up at 900' DA. Did motor run total lost ??  George now a dayz their is no 10.90 class so you would have to run in ST/ET or SUPER PRO/ET.  33's might be big, would need small main jet, I took 33's and put a 31mm insert on motor side for a 1000 KZ BUILT and it ran fine at the track, had to change main jet with the DA changes.

POPS BK911

[joe p]

Yes, total lost and all Dyna with 13.5 pistons and with the head cut made lots of compression. I remember I had to use a diesel gauge to check the compression.

[gschuld]

Joe P,

    Thanks for the info.  But could you tell me what you were riding?  A 300lb chrome-moly lay down dragster, 450lb modified stock frame bike?  Something else?  I'm trying to get a feel for the WEIGHT of the bike+rider to better calculate power output.  That's such a huge part of the drag racing performance equation that I have to ask.

Thanks,

George

[Bill/BentON Racing]

Cool,what #'s did that diesel gauge show,over 200,I'm sure!....230-240? Thanks,Bill

[joe p]

I got my Bike back from Texas this weekend. WOW! It's going to need a lot of work! I got my old RC headers that I had on my 750 Street bike and my 33 Mikuni I ran on my old 1100F I had back years ago. I will try and post some picture this weekend.

[joe p]

That was a long time back. but when it was hot (gold rod sets up at .045) It was I thank 245-250. That may be wrong, getting old.  It had dark valve marks on the pistons. I do like compression, My KZ 1428 with a J head reads 287Lbs. The only way to get my big butt moving. LOL

[Sam Green Racing]

Ever thought of loosing weight Joe, forget moving, start FLYING.

Looking forward to the pictures, the children like pictures....me to.

Sam.