Leaky carburetor bowl overflow stem

[71CB350]

So a few weeks back I completed my carb rebuilds on my newest project - 74' CB360. Today before installing I thought I'd run some Seafoam through them to make sure the float settings were good. Left side was good with no leaking or overflow from the bowl overflow fitting but the right side leaked. I removed the bowl and adjusted the float from 18mm to 20mm re-assemble and it still leaked from the overflow. Removed the bowl and manually raise the float while adding SF and it shut off as designed. I then took the bowl and started adding SF, when the bowl got about half full it started dripping from the drain fitting. I assumed I had a pin hole in the bowl overflow stem but was puzzled at how to repair outside of replacing. I thought about heat-shrink tubing. I did a quick search on the heat-shrink and found it to be highly resistant to solvents and fuels. Went to Harbor Freight and purchased a kit. Clean the stem, cut the proper diameter size, length and installed - VIOLA'! problem fixed. I re-assemble and tested, no leaks. Now on to the carb install.

[ancientdad]

Interesting idea, hope it holds up for you. Most just solder the brass standpipe.

Hello members, as a newbie to this sight I'm looking forward learning more from you guys as I tackle my 2 new Honda projects: a 1971 CB350 (pretty rough) lol, and a decent, all original 1972 CB175. Thanks for all the info I've already gleaned from this site. I'll keep y'all posted as I delve into my winter projects.

So I'm just curious, but whatever happened to these two you mentioned in your introduction? You never posted any progress for them or asked any questions about them, did they both turn out well?

[71CB350]

Wellll, the 350 is gonna take more work than expected. The motor is locked and while trying to remove the right side plug it broke off in the head. Hours of trying to remove it has left me setting this bike aside until I can get a donor motor ready and/or sell as a nice rolling parts bike. The 72' cb175 is an all original with 2400 miles, it's in great shape except for the exhaust. I bought this 360 off Marketplace at good price before Christmas, it just hadn't been started sense 2018. It too is all there, just needs a little love with the carbs and tank cleaning. It will be a bike I would like to keep and ride, the other 2 will be sold, (my wife says I have a problem right now, lol). My goal it to keep and ride the 360 and find a 72-76 750k to begin working on and keep as well. Anyway, I retired from my factory job of 37 years last week and these projects have me excited, they'll keep my creative and mechanic juices flowing for a while. ;)

[71CB350]

Ancientdad, you were right in your hint, "hope it holds up for you". The stem started leaking again. Removed the bowl and the HS was loose, :(. So now to the soldering question. What type gun or torch would I need to use? Will I damage the aluminum bowl if it gets too hot? Thanks in advance for your feedback

[LongDistanceRider]

Ancientdad, you were right in your hint, "hope it holds up for you". The stem started leaking again. Removed the bowl and the HS was loose, :(. So now to the soldering question. What type gun or torch would I need to use? Will I damage the aluminum bowl if it gets too hot? Thanks in advance for your feedback

Tom's out and about right now.
You can use a regular soldering gun to do this. Sand the crack so it's all nicely cleaned. Add plumbers flux along the crack and start soldering.
Once done blow thru the drain side to be sure it remains open, once in awhile the solder will fill/plug the pipe. If that happens drill thru the blockage so it's open.

[ausman1000]

I had the same problem and successfully soldered them up just as LDR above has described. The cracks are not necessarily easy to see either! Zoom in on this pic to see the crack before solder was applied.

crack2.jpg