Topic: Keihin CR Carbs....

[MRieck]

You are right on with the your info....except....."The downside to the CV carb is a lack of immediate throttle response. Twisting the throttle gives relatively leisurely acceleration compared to a conventional carburetor"....Not so true....there are ways to take care of this and the operation of CV carb is MORE responsive and smoother run with a more balanced flow. My launches like you were on the shuttle.

Well tuned CV's are nice. The flatslide versions are especially nice. FCR's only offer 2 or 3 extra HP on top from flatslide CV's. Heavy, round metal slide CV's leave something to be desired.

[heffay]

hey thanks for the carb lessons guys    anyway, before i asked i was 99% positive it was constant velocity... now how bout that CR... constant ratio?  i've looked many places online, before i even asked the first time, to try to find a definitive answer but have had no luck.

as far as differences between the two.  i've got FCR's on my zx7r and we all probably know the troubles i've seen with those but, if you dial them in they are ok... just really boggy getting off the line... it's a slip the clutch to 11grand and go kindof bike.  upper rpm ranges on the other hand are extremely fun.  twist the wrist the tiniest bit and you can feel it.

i've also dealt alot with cv carbs especially on ex500's.  the design is awesome for street bikes but vibrations can destroy there rideability and they suck for offroad purposes.  easy to work on, blah blah blah.

so, i actually understand the workings/design of these carbs better than i understand their acronyms    hopefully not for long...

[Hockers Choppers]

I work with a guy that had a honda shop for 35 years. He told me cr stands for "competition racing". I don't know maybe he's full of it. But He seems to know his stuff. He rattled off the Honda part #'s for the points of my bike off the top of his head! He raced for 30 years also, mostly flat track.

[MRieck]

I work with a guy that had a honda shop for 35 years. He told me cr stands for "competition racing". I don't know maybe he's full of it. But He seems to know his stuff. He rattled off the Honda part #'s for the points of my bike off the top of his head! He raced for 30 years also, mostly flat track.

That's right...That is what I heard but...nothing offical from Keihin

[heffay]

sorry hockers... i must have overlooked the previous post where you said that.  thanks guys!  one less dummy in the world.

[Hockers Choppers]

Like I said, I don't know....But this guy seems to have been around Honda's more that me! I work in the body shop at a Chevrolet dealership and this guy is a car salesman ( He is very cool so don't hold the salesman thing against him!) He had a bike dealership from 1960's till 1990! bulltaco? Suzuki, Honda, etc. Like I said, he's been around bikes. He loves coming back to the bodyshop to see what I'm messing with. I'm only 35 and have been on Harley's for the last 20 years but now have 4 young kids and no time or money for big dumb bikes. I stumbled on the a 78f and here I am. I love it and  have it in a million pieces this winter. They are built like a brick s++t  house!! Can't wait to get it back on the road. Still need a big bore piston set! Santa are you listening?!?!?!?

[Jonesy]

I also read in a book on Honda bikes that CR stood for Client Racer.

[sparty]

CR could stand for "Cost Restrictive"

In my case, it stands for "Cafe' Racer".

Sparty

[Hockers Choppers]

CR could stand for "Cost Restrictive"

In my case, it stands for "Cafe' Racer".

Sparty

I like those names much better!

[Hockers Choppers]

OK..got the 29cr carbs today! I thought they were the wrong ones at first. The spigots are smaller than the stock carbs. The bore is 29mm. The spigots are 34mm! smaller than the stocks. YY8 needles, 45 low speeds. Will I need to get bigger spigots or smash them down with the clamps? Are the rest of the jets/needles OK?

[sparty]

OK..got the 29cr carbs today! I thought they were the wrong ones at first. The spigots are smaller than the stock carbs. The bore is 29mm. The spigots are 34mm! smaller than the stocks. YY8 needles, 45 low speeds. Will I need to get bigger spigots or smash them down with the clamps? Are the rest of the jets/needles OK?

Not sure what you are asking with the "spigots"?  My 29's fit perfectly into the stock rubber manifolds.

Sparty

[Hockers Choppers]

The adapters that screw into the front of the carbs.

[MRieck]

OK..got the 29cr carbs today! I thought they were the wrong ones at first. The spigots are smaller than the stock carbs. The bore is 29mm. The spigots are 34mm! smaller than the stocks. YY8 needles, 45 low speeds. Will I need to get bigger spigots or smash them down with the clamps? Are the rest of the jets/needles OK?

The YY8's should be OK. The pilot jets will probably work.

[Hockers Choppers]

should and probably, scares me a little.   Are these the correct jets?

[heffay]

since "we like pictures"
these are my keihin 39mm flatslide carbs...
hopefully, you don't mind yet another heffay's zx7r intrusion 

[yd72]

Hi to all who post in this forum. I am a newbie in this forum. I have been  reading this forum for a long time but haven't post before. This will be my first....

Can anybody help me and assist on some cr carbs questions.

1) Where can I get the cheapest cr carbs for a 350f? What model and system, which is best for cb350f?
2) Can anybody help me,on how to install this carbs properly with instructions and maybe photographs.
3) Any advantage and disadvantage of cr carbs for daily use?
4) Any difficulties in tuning the carbs, can it be done by yourself? Any where can buy the instruction manual?
5) Finally, any modification to the bike? And any final adjustment?

Appreciated anybody contributing to the answers. God bless everybody. Thanks.

Regards
Chris