Honda C102 scooter carb issues

[placek59]

Hello All,
I have a '67 C102 with 488 original miles on it I bought a few years ago from the "2nd" owner. I believe it had about 10 miles on it when he got it in the mid 70's. Anyway, he rode it off and on while in college and then it pretty much sat in his garage until I bought it. The problem I am having is with the carb. It leaks fuel out of the two vent tubes on the bottom. It runs pretty good at an idle but that's about it. I rebuilt the carb and it still does the same thing. It seems to me that the float isn't floating high enough to seal off the needle and seat. Does anyone know what the dimension should be from float to needle or if adding another notch to the needle where the clip to set the float height (so it would float higher) goes would help? Any thoughts are appreciated... Here is a link to a repro on ebay. These carbs are different than the ct70 carbs in that they mount directly (vertically) on the head without the curved intake tube. I am pretty sure that it is rebuilt properly...
Thanks-
KP
Brand New Carb Carburetor Honda Cub C50 C65 C70 | eBay

 

[birdmannn101]

I have the same problem on my C102 carb. I notched the float needle up some and that didn't help. Bought a rebuilding kit and that didn't help either. I am suspecting this rubber part with all the holes in it needs to be replaced because I bought a new carb from someone in Greece and had the same problem with it leaking.



Buying an aftermarket carb means that you NEED IT A LITTLE BY DRILLING OUT AT THE MOUNTING BASE. This takes awhile if you don't have a drill press. Mine leaked when I got it off Ebay and the seller was nice enough to send me another carb which I took apart to fix the one I bought.

Let me know if you find a solution for the leaky carb.

Dan

 

[scooter]

On one of my carbs,the float was glued to the bottom of the bowl by the evaporated gas gum. Wasn't an adjustment problem just needed a good cleaning

 

[placek59]

Scooter- unfortunately that isn't the case with this one...
Birdmannn- that isn't exactly promising news, at least they sent you a free one to get a working one. I hope it doesn't have to come to that for me. I wouldn't have a problem with the holes in the mounting base as I could put it in the mill and slot them ever so slightly but if they still don't work, yikes!

I will keep trying to play with it and see what I can come up with. This is a plastic float in this one. Would that be the correct or original part?

 

[birdmannn101]

Placek59 - Look at that seller's negative feedback. He only answers 1 or 2 and makes no comment for the rest of his crap he sells. Let me tell you, I normally would send a friend a free part that he needs and in this case I do have the extra carb he sent me to cannibalize but you would laugh your butt off when you got it. Parts are rusted and it looks like the carb spent some time in salt water with all the corrosion it has on it. Seriously, if you want it I'll send it to you but you would be better off with your old carb. Yes, it does have a plastic, sort of rounded edges float. I remember once (before I cleaned it) it stopped leaking. Seemed like the needle valve has a tendency to come up off center and doesn't hit the center of the hole in the top. You sound like you have some tools to try and take a better look at it. I only threw in the carb kit as a last resort.

Thanks for your input Scooter.

 

[scooter]

I have a project bike with that carb. I think I'll get on it and see what happens when I rebuild it. I'll bump it up on the to do list. Maybe I'll see the same thing.

 

[birdmannn101]

Hey Scooter - Any pictures of your project bike?

Mine started out as a $100 rusted, non running C102



... and I am waiting on buying the plastics after I replace 2nd gear.

 

[scooter]

Bird man - I'll post up a picture. Mine has a little history. It's what I received in exchange for returning a ct70 that I acquired to it's original owner. It was stolen from him as a kid about 35 years ago. It's in pretty bad shape but I intend a full restore. I have new rims new spokes some Nos speedometers for that model. Let me know if you want one. I think I have three. I also I have a bunch of Nos blinker covers ...

 

[placek59]

I found an old carb on ebay for 13 bucks hoping with the two I could get one decent one. I got it yesterday and took it apart to clean it up, and there were more parts than the one that is on my bike...? Turns out that the one on my bike was missing a large hollow "donut" that is held to the top of the float bowl by the needle seat. I cleaned it up and put it on late last night and it works now! It now leaks fuel from the gasket on the fuel on/off/res selector, but I have a good gasket on the other half to throw on. Just ran out of time last night. I hope that solves the problem... My rebuild kit didn't come with an assembly schematic and I assumed the carb was complete, but there you have it!

 

[birdmannn101]

Well, I noticed that once I opened the fuel off/res/on selector, fuel started running out of this tube #2 on the carb (see picture)



So, I took the float section apart and noticed that the float hit the bottom of the top section and the needle still had a way to go before it went in and turned the fuel off. There is only one notch on the needle for the "c" clip so I made another one further down so the needle would bottom out at the same time. What has been happening is that fuel continues to fill the carb till it reaches point #1, then runs out tube #2. While typing this, I see what might look like a spring at point #3 which I don't have in my carb. This would push the float down and allow the needle to close off the fuel flow while keeping the float down further. Well guys, you know how it is ... when your talking to another motorcycle guy you figure the problem out. I think I might be a happy camper. I'll let you know.