Topic: Vintage Keihin CR31mm Smoothbore (ticklers) Carbs

[gschuld]

I see the CR mention for the Honda 4s, but it sounds ambiguous regarding carburetion for 350twins.  I guess I didn’t read the relevant parts.  AHRMA rules are frustrating sometimes.

George

[slikwilli420]

I find that most classes require a carb with a slide valve, so the butterfly valve on a Weber would be a non-starter. Thought about running them on my S750 bike until I found that out. The VM carbs are so tunable, I can't imagine getting much if anything more out of old tickler carbs. Parts are too scarce to make using them a good choice in my opinion.

[dhidaka]

any thoughts on how much you'd sell them for? Might be a nice addition to my race bike.

Yes, I would be interested in selling my "ticklers." Carbs are clean inside. Slides work smoothly, just have grime from sitting on the shelf for many years. Just need TLC. Also, have an assortment of main jets. BTW: I did find some float bowl o-rings that will work, but not OEM. No parts are available at Sudco where carbs originally came from. (Carl at Sudco tried his best to help) Anyone interested PM me. But, thinking around $2K as they are, unless I decide to go through them. I can send whatever pics you like.[/size]

[cb550fcafe]

I see the CR mention for the Honda 4s, but it sounds ambiguous regarding carburetion for 350twins.  I guess I didn’t read the relevant parts.  AHRMA rules are frustrating sometimes.

George

yes very frustrating, George I've been arguing the rule for 2 years. Its non-sense. How is a race equal with a 400/4 and CR Specials racing against a 350 twin that cannot use CR Specials? AHRMA has hated the (wildly successful) CB350 Twin since it's arrival to racing. Its cheap, reliable, Japanese and plentiful. AHRMA and vintage racing got steam rolled by Todd Henning on cheap Hondas, they viewed him as a junk yard racer but he beat all of them. Since that time the sanctioning bodies (mainly AHRMA) have tried to kill all things Honda twin. AHRMA tends to favor small 2 strokes, its seems to be the soup du jour.

[Finnigan]

Do these have the idle circuits?  Are they considered race only or could you use day to day?

[gschuld]

My understanding is the very early and every rare Sandcast CR race carbs did not have an idle circuit, but the diecast versions that superseded them do have an idle circuit.  Parts on the early type diecast carbs are not as easy to get compared to the modern type CRs. 

FWIW, some early type diecast CRs are actively being used in race bikes.  Mostly on genuinely vintage race bikes or period correct style race bikes.  Otherwise modern CRs are more practical.

But yes, the diecast ones could be considered streetable I guess.

George

 

[bwaller]

I see the CR mention for the Honda 4s, but it sounds ambiguous regarding carburetion for 350twins.  I guess I didn’t read the relevant parts.  AHRMA rules are frustrating sometimes.

George

yes very frustrating, George I've been arguing the rule for 2 years. Its non-sense. How is a race equal with a 400/4 and CR Specials racing against a 350 twin that cannot use CR Specials? AHRMA has hated the (wildly successful) CB350 Twin since it's arrival to racing. Its cheap, reliable, Japanese and plentiful. AHRMA and vintage racing got steam rolled by Todd Henning on cheap Hondas, they viewed him as a junk yard racer but he beat all of them. Since that time the sanctioning bodies (mainly AHRMA) have tried to kill all things Honda twin. AHRMA tends to favor small 2 strokes, its seems to be the soup du jour.

Truth

[simon#42]

the reason they are disliked over here is that they were never raced in the day , how can a bike that was never raced in the period be classed as a classic racer ?

[slikwilli420]

the reason they are disliked over here is that they were never raced in the day , how can a bike that was never raced in the period be classed as a classic racer ?

Because they fit the guardrails that the rules have in place. They can make very respectable power and are ridiculously plentiful. Many people in the states share your viewpoint and if that was the way AHRMA decided to go, vintage racing in the states would evaporate over night. Very few people who are competitive racers on quality built machines wouldn't bother if required to race a period race bike with hire price tags and unavailable parts. Id be one of the guys that hung it up.

[simon#42]

thats because you are to young to have raced in the day ( not a bad problem ! ). the classic club in britain was started with the aim to preserve and use classic racing machines . it was not started so people could go racing on the cheap . if cost is the reason to race classic bikes why not race a 90s bike somewhere ,  some of these are a fraction of the cost of a honda twin that never was a racing bike anyway .

[turboguzzi]

interesting discussion, but isnt the CYB350 production racer a precedent?

sure never sold in big numbers  but at least some used it...

https://4-stroke.net/105-articles/1147-honda-cyb-350-racing-rsc-original-model.html

has ticklers though

my copy of Mick Walker's "Japanese production racing motorcycles" is not next to me right now, will have a look next week.

[Old Scrambler]

Turbo............thanks for the pics...........several frontend & perch/lever items are borrowed from CB77 and CL77 models.

[slikwilli420]

thats because you are to young to have raced in the day ( not a bad problem ! ). the classic club in britain was started with the aim to preserve and use classic racing machines . it was not started so people could go racing on the cheap . if cost is the reason to race classic bikes why not race a 90s bike somewhere ,  some of these are a fraction of the cost of a honda twin that never was a racing bike anyway .

Fair point, but time marches on and people want to race what is available. I'm 35 but by all accounts an old soul. 90s bikes are boring to me in every way. AHRMA means to preserve racing up to the 70s as its main focus. I love my cb750 and may never race anything else. There are great new parts that rehab these street bikes and allow them to be weapons on the track and as long as the field is fairly matched performance wise they should be able to race. Even a budget race program involves $10,000 a year in race fees, lodging and travel expenses on top of building a great bike which can run into the 10s of thousands easily.

[simon#42]

its great that you younger racers choose to race the older bikes , without you it would be all but over . anyone that raced in the 70s is knocking on 60 at best . i raced classic bikes because i still loved the bikes i raced when they were new . i know the honda twins are here to stay and provide great racing its just i would prefer things to stay as authentic to the time as possible . racing has never been cheap when i first stoped it took me five years to pay all the debts i had run up ! . the joy of classic racing was i could afford it .

[simon#42]

interesting discussion, but isnt the CYB350 production racer a precedent?

sure never sold in big numbers  but at least some used it...

https://4-stroke.net/105-articles/1147-honda-cyb-350-racing-rsc-original-model.html

has ticklers though

my copy of Mick Walker's "Japanese production racing motorcycles" is not next to me right now, will have a look next week.

i think this is how they qualify to race , there was supposed to be 18 made but none made it over here . most of the pictures are from the 68 tokyo motor show . have never seen a picture of one racing .

[gschuld]

http://www.vf750fd.com/cyb350/

To say the cb350 was not raced in the late 60s/early 70s time period would be bit of a stretch.

The small Honda CB twins today make up a sizable proportion of AHRMA competitors today between a multitude of classes.  Make no doubt, they contribute greatly toward keeping AHRMA financially viable and healthy in terms of both good competition and ability to bring in new members.

Without them, many teams would not be racing today.  And those machines have offered many entry level racers an avenue to dip their toes in racing without having to sell a kidney or deprive their kids a college education(or just stay within a regular Joes family budget)

I certainly believe they have their place in today’s vintage road racing.  Some can financially justify spending 2-10 times the amount to race something more rare or valuable(Nortons/Triumphs/Ducatis /BMWs/two stroke Yammies, etc). That’s great and everyone loves to see them. 

But without the financial support and extra competitors offered by the small Hondas and similar bikes, I have doubt personally that ARHMA would be strong enough as an organization to put on the events they do.  Some would call that a necessary evil. I don’t personally see anything evil about it.

George

[simon#42]

thats because you never raced in the period either .

[gschuld]

thats because you never raced in the period either .

Thank goodness for that...🤣.   I’m a good number of years away from needing one of those powered lift chairs😉

George

[simon#42]

i have a tz 750 engine under my bench earmarked to power mine !

[johno]

Yep, that would be better than an electric one Simon, with battery the faster you go there sooner you stop .

[bwaller]

I think we forget we're all on the same side.

It's tremendous that young guys learn how to keep an older bike race ready. The biggest problem in NA vintage racing is the lack of desire to learn this. Older period machines and classes are dwindling, not only because of machine availability, but because so many young guys can't be bothered to get their hands dirty. If the lowly CB350 helps prop up organizations, so much the better.

I say lowly CB350 because for the summer of 73 my brother in law lent me his while he was in the Arctic. It was my commuter to work, which was basically their intention. I would never in my wildest dreams then think there would be thousands of those bikes populating race classes everywhere now. But here we are and there are some very fine racebike examples.

I understand what Simon is saying and it's great that there are places in the world that can field older classics. It's just getter harder & harder here. I retired from racing in the 70's and when I returned the same bikes (and many riders) were called vintage. I thought it was cool.

TZ750, just another example. I've seen two in as many years, very sad.


 

[MRieck]

I think we forget we're all on the same side.

It's tremendous that young guys learn how to keep an older bike race ready. The biggest problem in NA vintage racing is the lack of desire to learn this. Older period machines and classes are dwindling, not only because of machine availability, but because so many young guys can't be bothered to get their hands dirty. If the lowly CB350 helps prop up organizations, so much the better.

I say lowly CB350 because for the summer of 73 my brother in law lent me his while he was in the Arctic.

Brent.....is that where Canadians go for vacation??

[bwaller]

You know it Mike. We only need a hot sauna and a decent sized hole in the ice!