1/4 rod keeps breaking.

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Krahammer
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1/4 rod keeps breaking.

Post by Krahammer » Tue Jul 04, 2017 10:17 pm

The center rod that holds my flame arrester and hood onto the top of my Holley Carb keeps snapping off. I have tried all kinds of threaded rod, including hardened rod, to no avail. I don't want that thing to fly into my prop. Any ideas?

SHOOTER250
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Re: 1/4 rod keeps breaking.

Post by SHOOTER250 » Wed Jul 05, 2017 5:41 am

Until you figure out how to stop that you better safety wire your spark arrester to the motor

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Andy
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Re: 1/4 rod keeps breaking.

Post by Andy » Wed Jul 05, 2017 5:59 am

I had the same problem, I ended up drilling and tapping it up to 5/16. It hasn't broke since, I have a Quick fuel don't know if you have enough metal?

SWAMPHUNTER45
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Re: 1/4 rod keeps breaking.

Post by SWAMPHUNTER45 » Wed Jul 05, 2017 7:10 am

If it is over sized it may require you to ad some bracing to reduce the force and harmonics it is exposed to.

Krahammer
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Re: 1/4 rod keeps breaking.

Post by Krahammer » Wed Jul 05, 2017 4:26 pm

thanks for the responses. Safety wire done the first time the bolt snapped. The 1/4 inch hole is not oversized. I will have to check and see if the Holley has room to drill and tap to 5/16. However, it doesn't seem enough of a difference to keep it from snapping.

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mojoe
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Re: 1/4 rod keeps breaking.

Post by mojoe » Wed Jul 05, 2017 5:52 pm

Krahammer wrote: The 1/4 inch hole is not oversized.
I don't think he is asking if your hole is oversized, he is talking about the filter/flame arrester. Some people put some pretty big ones on there.

I ran a Holley for years with a 10" filter and a dog bowl to keep the rain out. It was drilled and tapped to 5/16". It was like that when I got it and I never knew why, but i never had a problem so I didn't think about it much. Just put some 5200 on the threads to keep it from vibrating loose. Ran it 4+ years.
Mark 7:9

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Re: 1/4 rod keeps breaking.

Post by GMAC 76 » Wed Jul 05, 2017 9:42 pm

have ya tried a long 1/4" BOLT with a lock washer instead of threaded ROD and a nut??

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Deano
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Re: 1/4 rod keeps breaking.

Post by Deano » Wed Jul 05, 2017 10:19 pm

The Holley does have sufficient room to drill and tap for 5/16".
I had similar issues with mine years ago, and that was the fix for me.

I additionally bottomed out a rod coupling nut against the base, like a jam nut.
This helps to spread any strain over a greater area of the stud.

Haven't ever had that problem again in seven or eight years now.
"The suppression of uncomfortable ideas may be common in religion and politics,
but it is not the path to knowledge; it has no place in the endeavor of science."
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Krahammer
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Re: 1/4 rod keeps breaking.

Post by Krahammer » Wed Jul 05, 2017 10:36 pm

Again, thanks for all of the suggestions. I already use the coupler nut idea, it keeps the rod from breaking off level with the top of carb and having to drill it out. I like the bolt idea, it has to be stronger than threaded rod. Before I drill and tap, I'll try it.

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