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The question: what type of thread sealer should I use on intake manifold plugs
why:
Had loud exhaust popping and surging issues. Found a bad carb plug, replaced it, and solved the issue. I thought. Today I went for a drive with my exhaust cutouts open, and I could hear popping through the exhaust when crusing or lightly accelerating. I’d call it slight popping because it is only noticeable with open exhaust, the mufflers completely hide the pops.
Did a quick survey and found the headlight manifold vacuum port was loose. I pulled it, cleaned the threads and put plumbers tape on it. After reinstall I sprayed it wiht some carb cleaner, and it affected the idle, leading me to believe the port is still leaking. What should I use to seal the threads?
Last edited by Cmurray79; Sep 13, 2021 at 08:52 PM.
The threads make the seal. Teflon tape or paste is used on tapered pipe threads as lubricant, not to actually make the seal.
That said, you could try Teflon plumbers tape. Or you could replace the fitting with a tapered pipe plug, if you aren't using the port, which would let you screw it in tighter with no consideration to orientation.
Are you sure the carb cleaner wasn't being sucked in somewhere else, like the carb base gasket?
The threads make the seal. Teflon tape or paste is used on tapered pipe threads as lubricant, not to actually make the seal.
That said, you could try Teflon plumbers tape. Or you could replace the fitting with a tapered pipe plug, if you aren't using the port, which would let you screw it in tighter with no consideration to orientation.
Are you sure the carb cleaner wasn't being sucked in somewhere else, like the carb base gasket?
yes I sprayed other areas to get an idea of what to compare too. My hoses are old, if not original. I removed the plug again and tightened it as far as I could. Right now i’m in the process of clipping the ends of different lines and reattaching them. I am using the port for the headlights. They work well, left one is a little slow goin up though. I have a long trip next weekend which I’ll be sustaining around 3000-3300 rp for 3 hours. I dont want to run it lean that long
Last edited by Cmurray79; Sep 13, 2021 at 09:43 PM.
Manifold Vacuum Fitting Leak
