Carb Cleaning Surprises

We've cleaned lots of old, gunky carburetors over the years, but cleaning the carbs on a Honda CB350 yielded some extra surprises!

First was the inside of the float chamber...looking pretty bad!

But the bottom of the float bowl was much, much worse! What are those chunks?

But with a lot of carb cleaner, gasoline and elbow grease, we were able to get it all cleaned out. We replaced the float bowl gaskets and put it all back together. But upon filling it with gas, we noticed a leak! At first we thought it was a stuck float needle, then ruled that out and suspected a bad seal or a crack in the overflow tube, but further inspection showed that the gas was actually coming out of a really strange place...
See if you can spot it in this photo:

 Wait for it....Bam! The gunk in the bottom of the float bowl had actually eaten a pinhole through the aluminum float bowl. In the picture above you can look closely and see a small black dot. After further digging around, we enlarged it to the size below:

 We don't have the ability to do aluminum welding at the moment, so soldering was attempted but didn't hold. Luckily, there was a replacement float bowl on hand and so we swapped them out. After that, the bike was actually running great! The bike ended up being probably the strongest-running old Honda twin we've had come through the shop!