Topic: Screwed the pooch! - broken float bowl overflow stem

[bluedude432]

My first post (sorry I talk so much)! So a buddy of mine gave me his '78 cb750F because he knows I love projects and he was moving out of state and didn't have room. It ran briefly before I decided to start with tune ups and repairs. Now I'm a complete novice at bikes but I handled the oil, breaks and clutch with no problems (so far) and ran the bike about 50mi until it just didn't sound right... Carbs of course! right¿!? So after reading the forums I take on the task of rebuilding the carbs. It took me weeks! I doubt I have it all 100% heh! I'm wondering if they're even 70%. The bike won't start for nothing! I mean maybe 2-3 seconds with full choke then sputter to nothing. First I noticed that exhaust time 2 was cold (opened the idle mix screw to 2.5 and that helped) but I can't get her to run long enough to sync. So I'm tracing and trouble shooting air flow, vacuum, ignition, spark, idle, valves, condenser. Basically everything that she's been needing for what looks like a very long time. She's old and dirty just like I like 'em.

What I'm needing help with is a tough lessen in being over zealous with a bristle wire wheel and screw gun. I snapped the float bowl overflow stem off right at the base. I tried the extra strong JB weld and that lasted about 2 weeks, I tried soldering it but apparently aluminum needs special solder to stick because mine kept loosening immediately.
 
Also, I can't find a replacement #2 float bowl for a set of PD42A carb's anywhere! I don't want to shell out for a whole new set of carbs just to get the float bowl. I think I'll just hopefully find some hobby brass and see if I can wedge a piece in what's left if I can find a hollow piece. But a piece of me is wondering how long could I get away with just plugging it. Ideally, I'll figure out how to get a screw in there and pull the remaining piece of broken brass out so I can stuff a new brass stem inside it. Thoughts?

I posted some pics of what the bowl looked like when I first opened it and now. The pitting is something else.

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[robvangulik]

Like you said, find a right size screw, heat the bowl and it should pull right out.
You'll find plenty copper tube sizes in hobbyshops etc.

[ekpent]

 Post an add in the wanted section of the forum also.

[calj737]

You can send that carb body down to Jim French and he can micro weld it back better than new.

Bill or David Benton probably have your bowl, maybe even new carbs too. Send either of them a PM.

[robvangulik]

You can send that carb body down to Jim French and he can micro weld it back better than new.

Bill or David Benton probably have your bowl, maybe even new carbs too. Send either of them a PM.

What' s to weld? Just the copper overfow tube is broken...

[calj737]

You can send that carb body down to Jim French and he can micro weld it back better than new.

Bill or David Benton probably have your bowl, maybe even new carbs too. Send either of them a PM.

What' s to weld? Just the copper overfow tube is broken...

Misread what you broke. Get the bowl from the Benton boys-

[bluedude432]

Thanks Rob and Calj. I think I'll try heating and pulling. If I FUBAR it up enough I'll post an ad or reach out like ya offered. Thanks for the advice!

You can send that carb body down to Jim French and he can micro weld it back better than new.

Bill or David Benton probably have your bowl, maybe even new carbs too. Send either of them a PM.

What' s to weld? Just the copper overfow tube is broken...

Misread what you broke. Get the bowl from the Benton boys-

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[flybox1]

PM me if no luck.  I think I have a few PD bowls layin' around.

[przjohn]

I know what it is like to want to get a project moving forward, you want to tackle everything head on, yourself, I get it. Wire wheeling a carb bowl though? There are other ways to clean that crud out. My first choice is Vapor Blasting, Then there would be carb cleaner. My point is, patience is key when working on vintage bikes. If it doesn't come together today, there is always tomorrow. The knowledge and experience on this site is invaluable, I know from experience. Ask questions, guarantee if you had posted a pic of that bowl and asked how to clean it 2 things would have happened:

1. No one would have said to get in there with a wire wheel. 
2. A bunch of other options would have been presented.

Slow down and go faster is an old racing saying but it also applies to these vintage bikes. Best of luck with your project, and post some finished pics, always interesting and great to see bike pics.

[Don R]

 Keep that bowl for the clear tube float level testing method.

[bluedude432]

Great idea

Keep that bowl for the clear tube float level testing method.

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