Honda Elite CH150 - Does the carb have a cooling line on it? By nikegman (Read 4,065 times)

[nikegman]

Hello All,

I am working on piecing back together this scooter as we saved it from heading out to scrap. The gentleman that we purchased it from removed the carb and the lines that ran to it. We got it back together and the bike is up and running there's just one problem, it's leaking coolant. We can see exactly where it's coming from and it is a line off the carb that is not connected to anything. Does the carb have a coolant line? And if so where should it connect? We checked the service manual and there is no reference about a cooling line off the carb in the literature or the diagrams. Any help would be greatly appreciated, thanks!

Colin

[tvnacman]

I don't think so .

John

[Bashan]

I didn't think they have coolant, but where is it coming from?! Can you post a pic of it? Rich

[nikegman]

Thanks for the quick help guys. I am pretty sure the scooter bug has caught me, basically researching this while at work!

Let's see if this works, if you click on the link below it will be the hose that is held on by clip #29. Just to further clarify it is the part number 15 with the hose that would be pointing down towards the ground when on the scooter. I am almost positive that is the one that is currently running down towards floor board of scooter and is leaking coolant out of it.

www.cmsnl.com/honda-ch150d-elite-150-deluxe-1985-usa_model1165/partslist/E++17.html

[Bashan]

I think it is coolant, it's even labeled "heater". Where does the hose off of the other nipple run? There's two on that part, one for the hose you mentioned and then another one pointing out. Rich

[nikegman]

I will have to take a look when I get home. I'm guessing its the feed for the coolant line, but I'll see if I can verify where it is coming from. If I can figure out where this hose leads to I'll be golden. Based on the length it definitely looks like it goes down towards the floor boards and then somehow would connect to another hose or fitting which would bring it hack towards the radiator. I've been searching under the scooter to see if I can find something that it would fit into, but still nothing. The service manual seems useless as far this one pipe is concerned. Thanks again for the help!

[Bashan]

One of those nipples has to be out and the other one in. Usually a carb feed will have a supply near the thermostat. Most of the time anymore they don't even hook the coolant up to the carb on the 250s. Nobody seems to be able to explain why you would need coolant through the carb on engines of this size. Rich

[nikegman]

On a bike with a larger engine do you know where a feed off a carb would usually go? I'm guessing they used the same theory here. It is definitely the return that is disconnected as the stream of coolant coming off this hose is steady. Would this on a larger bike route back to the radiator, the reservoir tank? Just trying to see if I can retrace this line from the opposite end. Thanks

[Bashan]

This is from the 250 Elite but Honda tends to do things the same. The red arrow is the supply off of the thermostat and #3 is the supply to the carb.

The red arrow on the below diagram is the supply to the carb and if you follow the return you see it hooks right back into the radiator at the blue arrow. This makes sense due to the fact that it's pressurized.

I'm not saying yours is just like this but it's a typical configuration.

[nikegman]

Awesome, thanks. You don't happen to know what is missing in the far bottom left corner do you? There isn't a junction box or anything down there that the hoses go into is there? If I'm looking at the pic correctly it seems like there is something down there...maybe not though. Thanks again

[Bashan]

It's just the hose, I had to cut it off of the pic to get something else on there. No box or anything, just a continuous hose from carb to radiator. I KNEW you were going to say that!

[richardv]

Would this be to keep the carb from turning to a block of ice near freezing temps. It then wouldn't be necessary in the warmer weather.

Just me thinking out loud.

[nikegman]

Great minds think alike haha!

Thanks again, much needed info as it was close to impossible to tell where this might have gone. I'll keep you updated when it's working! 

[Alleyoop]

Yes that is old techy stuff it really doesn't even work(HAHA). You will see a lot of the 30mm carbs on the 250+ motors with the two connectors bolted to the carb. Most just plug the Inlet and Outlet at the radiator.
Alleyoop