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careful with those float pivot pins

Posted: Sat Mar 01, 2014 9:00 am
by mikenixon
It probably seems intuitive to remove float pivot pins using pliers, but don't. It puts scratches and divots in them that often lead to the dreaded busted float pivot post.

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I am against using epoxy on carburetors. There may well be some exotic epoxy out there somewhere that works on carburetors, but I have yet to hear about it, and the usual JB Weld is not it. Here is a recent JB Weld find on a job.

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My experience is that JB Weld and at least one other kind of epoxy has its resin based leached out by gasoline, turning the epoxy into dust. As for JB Weld specifically, it is easily dissolved with any decent carburetor cleaner. That does not bode well for longtem use.

Re: careful with those float pivot pins

Posted: Sat Mar 01, 2014 9:18 am
by CYBORG
I have seen a number of "clever" repairs for broken posts. But the real fix is a float post repair kit that Randakk sells. Works great, and lasts forever. He also sells a neat tool for removing the pin. It also works really well.

Re: careful with those float pivot pins

Posted: Sat Mar 01, 2014 9:26 am
by mikenixon
CYBORG wrote:I have seen a number of "clever" repairs for broken posts. But the real fix is a float post repair kit that Randakk sells. Works great, and lasts forever. He also sells a neat tool for removing the pin. It also works really well.


Yup. I have the tool, compliments of Randall.

Re: careful with those float pivot pins

Posted: Sat Mar 01, 2014 9:28 am
by mikenixon
Here's another pix of that epoxied carb. Personally, my preferred method of repair is welding. I have done several this way (actual weld), which I feel is equal to replacing the carburetor as far as the quality of the repair.


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Re: careful with those float pivot pins

Posted: Sat Mar 01, 2014 9:44 am
by mikenixon
Here's a sample of the weld repair. Not the greatest picture, but you get the idea. The fella that does these for me is the star of the industry in this area of expertise.


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Here is his handiwork on a different carburetor, better showing his ability. Nice, huh?


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Re: careful with those float pivot pins

Posted: Sat Mar 01, 2014 9:46 am
by CYBORG
That is indeed some neat welding

Re: careful with those float pivot pins

Posted: Sat Mar 01, 2014 10:44 am
by salukispeed
My skills at Tig welding are weak to fair at best and My hat is off to the guy that can weld like that. He could probably weld Dog snot to Diamonds with one eye closed. Well done!!

Re: careful with those float pivot pins

Posted: Sat Mar 01, 2014 10:57 am
by DocRoot
weld Dog snot to Diamonds with one eye closed

I's like to see that! lolol

Re: careful with those float pivot pins

Posted: Sat Mar 01, 2014 11:13 am
by Whiskerfish
That is some fine welding WOW!!

Re: careful with those float pivot pins

Posted: Sat Mar 01, 2014 11:30 am
by mikenixon
Another angle of the same carb in pix 1.


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And a could be better shot of the machine he uses. He calls it microwelding. A lifesaver and for my money the best repair short of replacing the casting.


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Re: careful with those float pivot pins

Posted: Sat Mar 01, 2014 12:11 pm
by fish
yes beautiful work
done with welding rod measured in thousandths!

Re: careful with those float pivot pins

Posted: Sat Mar 01, 2014 12:17 pm
by DocRoot
He calls it microwelding.
Indeed! I could never hold the bead that steady by hand> I have done flame welding on alumunum for non-structural parts before, and that worked OK but nothing like this beautiful repair.
The shots of the JB Weld you show look fairly intact to me, not turned to powder. I am contemplating building up a jet tower and wonder if anything inside a float chamber holds up... Silicone?, urethane? I don't need the carbset, it's just for play and experience. But I'd like to mess around with it and see if anything works
Tower.jpg

Re: careful with those float pivot pins

Posted: Sat Mar 01, 2014 12:30 pm
by mikenixon
DocRoot wrote:
He calls it microwelding.
Indeed! I could never hold the bead that steady by hand> I have done flame welding on alumunum for non-structural parts before, and that worked OK but nothing like this beautiful repair.
The shots of the JB Weld you show look fairly intact to me, not turned to powder. I am contemplating building up a jet tower and wonder if anything inside a float chamber holds up... Silicone?, urethane? I don't need the carbset, it's just for play and experience. But I'd like to mess around with it and see if anything works
Tower.jpg


As I say, I wouldn't. The pix with the JB Weld is of a carb that hadn't seen much use after the repair (my customer didn't even know of it). I have both firsthand experience and that of a rebuider in seeing JB Weld disintegrate. If it dissolves in carb cleaner....? But others say they have run JB Weld for some time. On your example, you have structural damage. I would replace the casting. They're inexpensive enough.

Re: careful with those float pivot pins

Posted: Sat Mar 01, 2014 12:58 pm
by DocRoot
This is a 769 carbset that doesn't go on anything I own, but I just thought it would be fun to see if I could make it run something. It was cruddy all the way through and I have used it to committ the Randakk video to memory, to test my HS cleaner, and to pass the time with my bikes in the winter. If I can make it start a bike I will clap my hands, bow to the gods, and save it for parts. I had heard folks claim success with JB Weld (I haven't tried it) and just wanted to explore your experience so I could know where to use it and where not to. It soulds like no-where that touches gas.

Re: careful with those float pivot pins

Posted: Sat Mar 01, 2014 1:02 pm
by DocRoot
I had thought of making the jets seal by molding silicone around them (they seat firmly but the corrosion goes below the o-ring so the issue is leaking not holding steady). Do you have similar experience with silicone?