Over the past few weeks I've noticed a squeak coming from my heavy breather. I only hear it with minimal throttle - idle has no squeak, anything past about 10% throttle doesn't squeak. I've checked the tightness of the bolt with no difference.

Any thoughts?

The bike has caught some rain lately (sitting in the rain without the rain sock on), and that is the only difference that sticks out to me, but why a squeak?

 

are you putting your ear next to it while sitting on the side stand and applying throttle and it's obvious from the HB, or when riding it...which would be harder to isolate it as the HB I would think and could be something else..I googled Heavy Breather Squeaking noises and mostly sleep apnea and CPAP machines came up

 

Lol it still may be applicable to me!!

yes, it’s obvious it’s from the heavy breather. When I first start to take off I can hear it starting to suck air and squeak (it squeaks and “puffs” with each intake stroke.

 

hmmm...so it started right after a good outdoor soaking eh...maybe just remove, clean it out and reinstall with new gasket..not that much work..probably a long shot, just weird

re: "it squeaks and “puffs” with each intake stroke"
you have to realize your providing such easy material to work with right!

 

I can't say it started happening after it got wet, I just know that's one difference from normal circumstances. It's gotten wet before, just not sitting out in the rain for two days.

I will be cleaning the air filter and seeing what happens. It's got 2,500 miles on it since last cleaning, but as I said, it's gotten soaked and probably needs a good cleaning/oiling.

 

Well... I replaced my spark plugs and I didn’t like what I saw. I’ll post pictures later. The right front plug had spots of rust, all the way from below the boot all the way down the threads to the electrode tip. All plugs were tight, and the only boot that gave me trouble was the right rear, which wouldn’t let go from the wire and pulled the wire out of the boot slightly.

As far as the right plugs, I hate ‘em! The boots are a PITA to remove (without the proper tool!), and their location causes anything build up around the plug (stones, dirt, water, etc.). Thankfully I wasn’t forgetful and used a shopvac to vacuum out the debris before removing the plugs.

I added a small amount of anti-seize to the threads and a bit of dielectric grease to the inside of the boots. Cranked it up and it all sounded good, could hear detonation ’ticking’ with each stroke, but didn’t have time to ride it.

 

Good on you with the shopvac, but a good shot of compressed air will likely outperform the vac. This tool works works great on stubborn recessed M8 plug boots.

 

Thanks, barneyboy. I'll have to buy another wire puller as I can't seem to find mine after the move. I used a 5/32" allen to hook under the boot, grabbed the end of the allen key with vicegrips and pulled up - popped off easily. I'm temporarily living in an apartment during my move, so I don't have my air compressor. The ShopVac surprisingly worked well since it has a small nozzle attachment.

I nearly didn't look down at the spark plugs before wrenching, which would have proven disastrous with how much junk was in the hole. I added a note in my service manual to double check for debris - one would think Harley would have included that in there (given they include similar notes in other places, like brake/clutch fluid reservoirs).

 

I noticed a lot of debris in mine also, including some melted bits of asphalt(?) that compressed air wouldn't dislodge. I loosened the plugs a bit (1/8th turn), and gave it another shot of air incase anything dislodged while cracking them loose.

 

The gap on the plugs coming right out of the box ranged from 0.028" all the way to 0.042", and the spec is 0.031" to 0.035". I hope by "specked out" you didn't mean gapped.