What is number 3 on this fiche?

http://fiche.worldofpowersports.com/wps/showmodel.asp?Type=13&make=hondamc&A=287&B=23

It seems to me to be a water connection. One hose comes up from the water pump to one carb then a hose goes from the other barb on that connection to the second carb. Then another hose from the other barb on the second carb back to the engine.
At first glance I would say you. Could bypass the connectors on the carbs to do away with all this but the connectors have a port and two sealing o-rings going into the carb. That doesn't make much sense because there is no other water port to circulate the coolant.
The back story here is my bike has been sitting for a couple of years and I am having problems cleaning the carbs. This whole coolant line system was plugged. I have gotten all the lines opened up but I do not see a port going into the carb itself. I do not want to keep digging if there is no port and if there is a port where is it so I don't hack up the carb body trying to open it.

Thanks in advance,
Zach

 

3 is an oring. it comes as a set for the rack, would be my guess.

 

3 is actually a "joint set" that includes two of the o-rings and the two barbed connector I am asking about.

 

Well, it is for the coolant system which heats the carb. needed, must hook up

 

If the coolant goes into the carb there (which I don't see a port unless I still haven't cleaned good enough) where does it come out?

 

I believe, althought I havent disassembled a set, that it merely flows near or past the carb and heats it through conduction, rather than passages. It nearly flows completely outside the carb. Enough to heat it to prevent various carb related temperature problems.

 

Well I could tell you exactly how the coolant flows but then I would be called a know it all again.....

But to answer your question, the coolant never goes inside the carb body....

 

ok, thanks. This must not have anything to do with my dead cylinder. I will re assemble and hope it runs right.
Zach

 

As 8541 Hawk said, it never goes into the carb, and autoteach nailed it as far as how it heats the carb. But now as to why. It prevents icing of the carb. Ever notice how cold the valve stem gets when you let the air out of your tire by removing the valve core ?
Same thing happens with the air going through the carb. BTW that's how AC systems work.
Man, don't I sound like a know it all ?

 

I didnt think that was important, but as long as we are knowing it all...it also aids in atomization of the fuel which helps fuel economy and, the true danger of carb icing is the throttle sticking. The downfall or heating your carbs is boilover. so, there

 

and it's a system that shuts off when the thermostat opens.
But I won't get into what it does or why it is there as there are a few opinions on this.

Though I will say I found it impossible to ice the carbs here in CA. Though on further reflection on this, the lack of ice could also be a side effect of the amount of ethanol in the fuel here.

 

Speaking of fuel, I am fortunant enough to live between two lake here in TN and i am told that boats and boat tanks and Ethanol are bad combo. So we have Ethanol and non-Ethanol available for a nominal increase per gallon. And Ethanol is down to $2.89 here, yippie.

Back to the topic, i guess ig you installed a set of FCR carbs you would have to block the coolant hoses off or does anyone know if there is provision on FCR kit to hook the coolant up.

 

Well, it isnt the fuel that ices up. It is icing in the venturi, due to the pressure drop as the air passes thru the venturi and the heat of vaporization of the fuel. Moisture in the air condenses and freezes on the cold metallic surface.
Carburetor Icing

As for it shutting off after the bike is up to temperature, I could agree with that, if I didn't think that this bike constantly cycles the thermostat during normal riding and temperatures below 70-80 degrees farenheit. I could be wrong, but I might not be. This would mean that the thermostat constantly cycles flow past the carbs and then the radiators.

 

I think they are one of the coolest shapes/concepts. I love teaching kids about them.

 

Well here we go again...... While I was experimenting with the lines to see if I should leave them off or run them, I did try to ice the carbs.

Now I do know all about carb icing and how it is more related to the dew point and humidity than the outside temp. Now here in the bay area, we do have some prime icing conditions.

So while testing I was running for weeks on end where the temps in the morning were in the high 30's to low 40's with the dew point within 1 -2 degrees +\- of the ambient temp with the relative humidity always above 80% and at times very heavy fog and nothing, ever, no matter how hard I tried.

So at that time I reasoned that icing prevention was not the function that the carb heat was designed for. In fact there is a recent thread I started about this.

After some of the replies (and I just stopped bothering with the thread due to the childish name calling) I did come to realize that in some places, there might in fact be an icing concern.

This then led back to why couldn't I create a situation where it would happen. This is why I now believe the ethanol could be the answer.

Now for someone icing their carbs in the 70's and\or 80's, well there was no ethanol in the fuel then.

Also, they do sell a anti-icing fuel additive, which is....alcohol based. So that has led me to believe that the ethanol in CA fuel is the reason that icing is not an issue here.

But in any case, I also know that the bike runs better with the lines installed....

 

Well all you need to do is look at the thermostat itself:
Honda, ATV Parts, Scooter Parts, Motorcycle Parts,CRF,CR,MX Parts, Goldwing parts
Pos #2 and you will see that the thermostat has 2 disks on it and the thermostat housing has 3 lines going to it, one inlet and 2 outlets.

So when one side is open, the other is closed. if this were not the case, then there would be no need for a housing with 3 separate lines (you would only need 2 one in, one out) or a thermostat with 2 disks instead of a "standard" style thermostat.

 

I wasn't dismissing that it shuts it off, just arguing that during the running of the vehicle that this is not a permanent state once it is "up to temperature". So, basically contending that it continues to heat the carburetors as it cycles which would occur until ambient temperatures were at a level that would cause the thermostat to stay constantly open. As for why you couldn't get it to ice, I want to provide a hypothesis that this tends to occur when the venturi is operating closer to its peak efficiency, which could be difficult with a large carburetor at small openings. I did experience this on a family trip up north to go hunting about the time I was 15 (1995) in a Dodge Prospector (Ram Van). Don't worry, though, I am not calling you names.

 

"Drizzle, drazzle, druzzle, drome; time for zis one to come home." but I have no idea what you are talking about....

or maybe we should change the thread to identify that cartoon....

 

Ha, I have done that too. The kids couldn't believe the spray of water and how effective it was.

 

Oh I know you are not and that is why I am willing to discuss this....
and I rarely had the throttle at small openings. I was rather easy to sit at half throttle and above on the route I would talk and would intentionally hold it in one position in order to try and get some ice to form but could never manage to make it happen.

Though I will still say that no matter what they are actually intended to accomplish, in the long run, the bike does run better with them hooked up.

 

Well, I can agree with it running better, and I just remembered that I had the old snowblower ice up as well. They tend to run WFO.

 

I had carb icing in 1968 with my new CB350. Seems that the one night I left the machine outside and evidently moisture was trapped in such a way that the throttle plates iced up and the twist grip wouldn't return. The engine worked ok except that when you pulled the clutch in the RPM went sky high. Wouldn't matter much normally, but there was snow and ice everywhere. The key to turn it off was below the front left side of the tank necessitating a reach with the right hand while holding the clutch in with my left. No push pull cables or kill switch . Not directly on topic, but it was icing of the carb. Never happened again in the 43 years since.

 

Well I guess I missed that one completely then......

 

BTW, I'm taking full credit for keeping this thread alive with my icing comment at post number nine....

 

Mr. Wizard - YouTube

Mr Wizard's World- Episode 10 1/2 - YouTube

 

does anybody else think Mr. Wizard sounds like John Lithgow?

 

I still like "Help me Mr. Wizard" myself.....

 

I think we could agree that the heating effect is rather localized. What is that brass port right next to the "heater?"
Zach

 

Well do you have a pic?
As someone who is a bit familiar with these carbs, I can say there is no "brass port" next to the carb heat lines on either set of carbs that I have.....