Heads up on RTV silicone for plugging air cleaner back plates

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May 10, 2016 | 02:07 PM

djkolp

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Road Captain

Joined: Oct 2006

Posts: 658

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From: South Florida

Heads up on RTV silicone for plugging air cleaner back plates

I modified my Screamin Eagle air cleaner back plate for the DK external breather kit. I filled the holes that exit into the throttle body with Permatex RTV silicone, as has been discussed here on numerous threads. I set the back plate on the bench for 7 days to let it cure. The spec sheet on this Permatex RTV silicone stated that it took 24 hours to set up and 7 days to fully cure. It also stated that it had a continuous maximum temperature of 400 degrees and an intermittent maximum temp of 500 degrees. I just picked up the back plate this afternoon and was able to push the silicone plug out of the holes with minimum force, and it came out like it was coming out of the tube. The first 1/8" was solid, the rest was gooey. This air cleaner back plate was brand new, so there was no oily residue whatsoever. I don't know if riding the bike and heat cycling the back plate would have made a difference, but if the Permatex looked like that after 7 days, I wouldn't be comfortable putting any miles on the bike just wondering when that **** was going to break free and get sucked into the engine. I filled the holes with the Permatex until it exited the breather bolt hole, and then left a bubble to make sure it didn't get sucked out. So to ease my worry about this mod, I trashed the back plate and ordered DK's Arlen Ness external breather air cleaner. At least they weld the holes closed on that back plate. Bad batch of silicone? Maybe, but unless any of you that have used the Permatex for this mod have actually tried to poke it out, you might have the very same issue. Just thought I'd pass it along.

Dan

May 10, 2016 | 02:37 PM

voodoodrug

Stellar HDF Member

Joined: Sep 2006

Posts: 3,236

Likes: 95

From: lancaster, pa

theres no way i was going to use permatex there. used a fuel line hose and worked it with a razer blade to plug the hole and ancker around the breather bolt. still thinking about jb weld or another idea

May 10, 2016 | 02:46 PM

Roadie13

Stellar HDF Member

Joined: Mar 2013

Posts: 2,716

Likes: 1,813

From: In a house

Used JB weld on mine. Looked the same when I took it off after 2 years to trade in bike as the day I put it on. Rock solid.

May 10, 2016 | 02:50 PM

DXHD $100

Tourer

Joined: Jul 2010

Posts: 422

Likes: 12

From: Ivor VA

I drilled and tapped mine and used Set Screws then topped with a small amount of RTV to keep Screws secure.

May 10, 2016 | 02:52 PM

qtrracer

Ultimate HDF Member

Joined: Jan 2008

Posts: 6,532

Likes: 132

From: SoCal

Used RTV on mine 6 years ago, its still there. But I didn't fill the hole(s). Squirted in one side a bit and then squirted a bit in the other side of the hole. Maybe thats why yours didn't cure, no air can get to the middle.