Friday, April 20, 2012

How To Fix A Broken Float Post on CB750 Round Top Carbs

Ok. I know I might catch some flack for not just using a new carb body, but these carbs were really in good shape and I really wanted to use them as a set and they were the best I had. So the problem was a broken float bowl post. This seems to be a really common problem with these carbs and I have broken 2 myself when trying to get out the little brass pin that holds the float bowls in place. So these carbs I had were really nice and I was bummed that I was gonna have to tear them apart and use a body from a different set. I am a problem solver and I am always thinking of ways to fix things that are busted up. So I figured what the hell, I might as well give this idea a shot, I didn't have anything to lose.

How The Posts Are Supposed To Look

So for me the first step was to aquire another post. Since I didn't have the one that broke off I just cut one off a trashed body that I had that was missing a post as well.
The Donor Post
Then I grabbed one of the brass rods that usually holds the float bowls on and found a drill bit just under size (make sure it is under a smaller diameter than the brass rod, it has to be a tight press fit). I then drilled a hole in both the carb body and the new post a good 1/4 inch. (make sure this a straight and true, any drift and you will get an oversized hole and it wont be sturdy). 
The Carb Body With Hole Drilled


The Bottom Side of The Donor Post With New Hole

I then pressed fit the brass rod into the carb body and trimmed it to the desired length with a pair of cutters
Carb With New Brass Rod

and then the new post onto that.
With New Post Before Setting Height

Tap the new post into place at the desired height and check it with a straight edge. Remember though, you are lining up the pin hole and not the top of the post.
Finished Transplant

Now your good to go. And let me tell you it is just as solid as it was before it broke. I found it to be a quick and really rather nifty way to fix an otherwise fubared carb. I hope it helps.

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