Bonehead move: stripped carb threads
#1
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From: Standish,
ME
I'm a little pissed at myself. I got a brand new Mag 52 engine. I was attaching the two cap screws to hold the carb onto the engine and ended up stripping one of them[:@] The engine metal is so soft I can't believe it stripped. One cap screw is more than enough to hold the carb on, but I'll have a nice air leak where the other screw should have went. Any ideas on what I can do? I don't have the right tools to re-thread. Thought about putting a little JB weld in the hole to plug it up, but not enough so that I couldn't remove the carb if I have to.
#2
[X(] I'm looking at my mag .28 as I type trying to figure out how you strong armed the screw into stripping.
any way take the screw to your local hardware or LHS and I am sure you can find another screw to fit.
Are you sure you have the lock washers on ? GL
any way take the screw to your local hardware or LHS and I am sure you can find another screw to fit.
Are you sure you have the lock washers on ? GL
#3
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From: Standish,
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I'm a little embarrased to say how I really stripped the threads, but anyways.....The mag engine came with 4 cap screws- 2 long, 2 short. The two long ones were in the carb bag, so I assumed they were the ones to attach the carb. I put one screw in no problem. When I tried to put the other in it was too long and was hitting the other screw. I was trying to figure out why Magnum would include two long screws for the carb knowing that one was too long. Out came the dremel and I shortened one. I took off the little burrs on the end of the screw then started screwing into the hole. Well I guess I didn't have "clean" threads where I made the cut, so I essentially stripped the hole. The weird thing is that there was barely any resistance when using the allen wrench, so I figured all was well, until the screw kept turning and not getting any tighter. [:@] Anyways, I opened the bag that had the muffler and low and behold, there were two shorter cap screws, presumably for the carb. Oh well, live and learn.
But do you think getting a slightly bigger cap screw will actually re-thread the threads on the inside of the carb? The metal or whatever material the carb is made of is so soft I'd think it'll just keep stripping.
The lock washer was on and I admit I didn't strong-arm the screw.
But do you think getting a slightly bigger cap screw will actually re-thread the threads on the inside of the carb? The metal or whatever material the carb is made of is so soft I'd think it'll just keep stripping.
The lock washer was on and I admit I didn't strong-arm the screw.
#6

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Here ya' go....I'd probably order the part for later....
....and re-tap it for now.
http://www.hobbypeople.net/part/21076002.asp
Dave.
....and re-tap it for now.

http://www.hobbypeople.net/part/21076002.asp
Dave.
#7
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From: Standish,
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So you don't think the JB weld will work? Who sells a set of taps anyways? Probably cheaper to just buy the carb body. I have a Mag 46 though. Are the carbs the same?
#8

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The earlier Magnum .40, .46. and .53 XL carbs wont fit on the new .52.
The spigot is smaller on the old carbs, they use the cinch bolt....and
the spigot (nounting flange) is shorter. Also they are not drilled for the
two screw carb hold.
Your screw is a 3mm, you might look for a 3.5mm screw and tap. The thread
pitch has to be the same for both. You can buy single taps at True value hardware
stores. You could possibly go to 4mm. or to 6-32 American
Trying to fill the old hole with JB weld and re-tapping the threads to stock
may or may not work....
When you install those carb screws, you must hold the carb down real tight
against the o-ring.
Unless you are skilled at re-working threads, you might be better off just getting
another carb body. At least that way it will be back to stock....and back to
brand new condition....and a lesson learned.
FBD.
The spigot is smaller on the old carbs, they use the cinch bolt....and
the spigot (nounting flange) is shorter. Also they are not drilled for the
two screw carb hold.
Your screw is a 3mm, you might look for a 3.5mm screw and tap. The thread
pitch has to be the same for both. You can buy single taps at True value hardware
stores. You could possibly go to 4mm. or to 6-32 American
Trying to fill the old hole with JB weld and re-tapping the threads to stock
may or may not work....
When you install those carb screws, you must hold the carb down real tight
against the o-ring.
Unless you are skilled at re-working threads, you might be better off just getting
another carb body. At least that way it will be back to stock....and back to
brand new condition....and a lesson learned.

FBD.
#9
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Any discount tool place should have a cheap set of taps.
Here's a cheap metric and SAE set:
http://www.harborfreight.com/cpi/cta...emnumber=45766
Here's a cheap metric and SAE set:
http://www.harborfreight.com/cpi/cta...emnumber=45766
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From: Standish,
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The earlier Magnum .40, .46. and .53 XL carbs wont fit on the new .52.
The spigot is smaller on the old carbs, they use the cinch bolt....and
the spigot (nounting flange) is shorter. Also they are not drilled for the
two screw carb hold.
The spigot is smaller on the old carbs, they use the cinch bolt....and
the spigot (nounting flange) is shorter. Also they are not drilled for the
two screw carb hold.
Trying to fill the old hole with JB weld and re-tapping the threads to stock
may or may not work....
may or may not work....
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From: Standish,
ME
Just checked Hobbypeople.net and looks like both carbs are the same. Think I'll just use the 46 carb for now and order the carb body replacement.
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From: Displaced Canadian in Central Texas TX
Had the same happen to me twice; both times on a 46XL; easy fix was to tap the hole with 6-32 tap, no need to drill the hole bigger; buy a 1/4 or 3/8 inch long 6-32 cap screw and good as new.
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From: Northampton, UNITED KINGDOM
It's a bit late now the damage is done, but using spring washers on the the carb mounting screws can lead to stripped threads. This is because you cannot feel the threads tightening - the spring washers absorb the tension somewhat but then the threads give.
Just use ordinary flat washers or even none at all with some thread lock.
Just use ordinary flat washers or even none at all with some thread lock.



