Atmosphere vent or overflow tube?

obscure44 · Post by **obscure44** » Wed Aug 20, 2008 1:51 pm

I read a post where LM said that the brass tubes on the bottom of the carbs for CB/CL72/77 were "atmosphere vents not overflow tubes" and therefore shouldn't have the hose connected to them. Is this also the case with a 1966 CA77?

While I'm at it, what all should be plugged in to the air filter? I've got the two crankcase vents also currently feeding into it. There's also a third tube coming from somewhere under the gas tank or top of the engine. Haven't looked to see where that leads, but it's not currently hooked up to anything on the south end...

Thanks!!
David

onchiman · Post by **onchiman** » Thu Aug 21, 2008 10:57 am

Well the CA77 parts manual shows a rubber hose connected to the brass fitting on the bottom of the carb (Honda part # 16235-259-000). It's labeled as an "overflow pipe". Mine has the hose and seems to have no ill effects. In fact, on my particular carb, a PW22, there are two vents in the top of the float chamber on either side of the jets. These are vented to the atmosphere through tiny holes in the carb body. I'd put a hose on there to at least route any overflow to somewhere other than the hot engine.

LOUD MOUSE · Post by **LOUD MOUSE** » Thu Aug 21, 2008 4:13 pm

As you have a DREAM with a DREAM carb you do require a tube as you have. However the CB/CL72/77 carbs are not DREAM carbs and when/if a tube is installed on that fitting the engine won't rev and is finicky at all RPM's. This week I've had 3 bike owners remove the tubes from the CB/CL72/77 carbs (this feller is one of them) and solve the RPM problems. Please keep in mind you have a DREAM and things are not the same as the CB/CL engines. His hose from the top of the engine passes down the rear of the engine and to the left side of the engine case cover through a slot cut in it and then to the right under the cover to a hole on the right side of the top case so the vapors will exit on the primary drive sprocket/chain. ....................lm

onchiman wrote:Well the CA77 parts manual shows a rubber hose connected to the brass fitting on the bottom of the carb (Honda part # 16235-259-000). It's labeled as an "overflow pipe". Mine has the hose and seems to have no ill effects. In fact, on my particular carb, a PW22, there are two vents in the top of the float chamber on either side of the jets. These are vented to the atmosphere through tiny holes in the carb body. I'd put a hose on there to at least route any overflow to somewhere other than the hot engine.

onchiman · Post by **onchiman** » Thu Aug 21, 2008 5:18 pm

obscure44 wrote: Is this also the case with a 1966 CA77?

I thought he was asking about the Dream. My mistake

obscure44 · Post by **obscure44** » Fri Aug 22, 2008 1:17 pm

Thanks LM! I'll keep the carb tube on there and reroute that other tube as you described.

splitenz · Post by **splitenz** » Fri Aug 22, 2008 5:34 pm

my CL77 setup.... The carbs are marked 26, what do you decipher from this lm?

LOUD MOUSE · Post by **LOUD MOUSE** » Fri Aug 22, 2008 5:47 pm

They are 26mm and throw that thing away. .............lm

splitenz wrote:my CL77 setup.... The carbs are marked 26, what do you decipher from this lm?

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Atmosphere vent or overflow tube?

Atmosphere vent or overflow tube?

Re: Atmosphere vent or overflow tube?