Harley Davidson Forums - Exhaust System Topics

Easy test for possible exhaust leak at pipe joints?

MotoJockey — Thu, 21 May 2026 04:18:03 GMT

Just had the bike dyno'd with a TTS tuner by a very reputable tuner. 22 SGS with a SE 447 torque cam, KW catless header, and TAB Bam Sticks. I still have a very slight decel pop occasionally, but maybe 3 times in 500 miles? Only when I get just a bit spirited with it like pulling out of a upsloped hair-pin in the twistys. So I want to eliminate any slight pipe joint leak as a possible culprit. What do you use? Incense or punk stick looking for the smoke to get sucked into the joint? I've tightened and retightened all the clamps twice now. MAYBE new clamps? Any other ideas to test them? I thought about a thin bead of something like orange high temp exhaust sealant around the OUTSIDE of the joints to see what happened. Like just enough to seal them, but can be cut off with a razor for slip-on or pipe removal. Any thoughts for a good test? :icon_denk:

Fullsac MX and S&S GN + Feuling 472 in a 117"

HFS — Thu, 21 May 2026 03:54:17 GMT

Initially; installed Fullsac 2.25" baffles in my CVO Mufflers. Ran stock headpipe. Right foot heat was a thing, but I could handle it.

FF to 2026, first ride, motorcycle did awesome, no issues. 2nd ride, a rattle and needed investigating. Turned out to be a few things: packing in mufflers was cooked. Pulled them and attempted a repack. Only got 8-10" deep installed. Couldn't resist: fired up muffler-less motorcycle... Loud-AF and then 'pooped' out the catalytic converter. Pretty amazing really. Already had ordered, and picked up Fullsac MX headpipe. Due to packing fight, said F-it and decided on the S&S Grand National Mufflers. I still have the db reducers in, but the motorcycle just wants to run now. It's pretty wild.

This is running very well, and I'm V-tuning [TTS] as we go. This is how these M8s were supposed to run. Oh: I put a Feuling 472 Cam in this past season. [Well RR Harley-Davidson did...]
Smooth clean power. 3000 + RPM is effortless.

YMMV

Is the long insert for the right muffler?

HarvHD — Sat, 16 May 2026 02:51:23 GMT

I want to try these mufflers to see if i can quiet the bike a bit, but I don't know which insert goes in which muffler. My guess is the long one is for the right side as more exhaust passes there, but I'm asking as I don't know.

American Customs?

M8 Softail Deepest Slip-on

MarcioTelles — Mon, 11 May 2026 16:01:55 GMT

Hello!

For those who have heard them in person on an M8 Softail, which 3.5� slip-on has the deepest and most low-end heavy sound?

I�m mainly comparing:

TAB Performance (louvered baffle)
Rinehart
Cobra 909
Khrome Werks HP Plus

I�m not looking for the loudest exhaust. I�m looking for the deepest, richest and most �bass-heavy� tone with less rasp/high-pitched sound.

S&s gnx 4.5 on TC

Weeboy1 — Fri, 08 May 2026 14:33:22 GMT

10 ultra stage 2
considering changing out my MGS custom mufflers for a set of GNX 4.5. Already have S&s powertune headers.
looking for opinions from those running these also bike is tuned based on current ad ons. Can these added with the tune as is?

Looking for FM R&T Black Ghost pipe

BlackPearl#1 — Tue, 05 May 2026 14:38:50 GMT

I know it�s a longshot, and I did check with Fuel Moto and they only made them for a short time. If anyone knows of one of these anywhere I�d be very interested.