float bowl brass over flow drain tube

zimmy

I've got a 79 cb750F that I've had a problem with 2 years ago when i got this bike back on the road. The #1 and #4 carb overflow brass tubes had verticle cracks in them (had to use magnifying glass to see them). Carbs leaked out overflow as a result. Not bad, but did leak if I left petcock on. I replaced bowls off ebay, but would like to avoid this in the future. I'm thinking of draining carbs early in the fall, before any possibility of frost, but hate to miss that nice late fall ride that usually comes up.

Any thoughts on how to avoid this in the future. I'm assuming draining carbs will help. Any ideas on how to fix, if I do end up with another crack, if mositure gets in the overflow tube and freezes. I'm assuming this is how they crack, but it is only speculation on my part. Any one else have this prob? IF so, how to deal with it best?

THanks,

fasterspider · Posted: Wed Nov 03, 2010 8:51 pm Post subject:

The brass tubes can be soldered.
I don't know for sure of a way to keep them from cracking.
My CBX which has always been a So Cal motorcycle that has never been exposed to freezing tempertures has 2 of 6 brass tubes that need to be repaired or replaced because they have cracks in them.
The cracks don't leak yet but, they are there according to Mike Nixon who rebuilt my carbs for me this past summer. Since CBX carbs are so frigging expensive, I will fix mine when they start to leak.

bB2NER · Posted: Thu Nov 04, 2010 9:37 pm Post subject:

When freezing is possible keep some Seafoam mixed into the fuel (1 oz. per gallon). It will help displace the moisture and still make it so you can ride it when needed. Plus it cleans the carbs nicely.