Author
Topic: Loud motor noise (Read 1016 times)

I'm still in the breaking-in stage (about to hit 300mi), so I hope this question isn't too ridiculous....I noticed that when I riding around town , at speeds where the wind noise on my ears isn't too great, the noise coming from the engine on the combustion cycle is louder than the exhaust note on the bike.  I still have the stock silencer, and I know it's pretty quiet, but should the motor be making that loud of a noise?  As far as the noise, it's not a rattle -like upper end bits- but more of a 'bang' on the combustion cycle.  I know the muffler end is far enough behind me that most of it's sound stays behind the bike.  But is it normal to hear that much...well, ...'noise' thru the cylinder walls?  Perhaps I'm being a bit paranoid, but all I can compare it to right now is my much quieter Japanese bike (vertical twin) so it's a little odd to hear that much coming from the front of the bike.  Any input or thoughts? 

the noise coming from the engine on the combustion cycle is louder than the exhaust note on the bike. 

during run-in you will hear alot of noise from the powerplant.  Mine made a kind of sand-paper on steel sound from the cylinder until about 1000 miles. 

The only thing I'd recommend is checking the two nuts that hold the exhaust pipe onto the cylinder head (one above & one below).  They have been known to rattle off during the first 300 miles.  They are fine once they burn into place ..... but they first few hundred miles, not so much. 

Sounds great to me.  There may be a bit of exhaust leak at the head though. Just good old thumping noises.  If your Jap bike as water cooled, that definitely muffles engine noises, but Jap bikes in generally are quieter then 50 year old English ones. Bare

My other bike is air cooled.  The W650 has some nice mechanical noises of its own with its bevel drive for the top end, but the BANG-BANG-BANG of the C5s combustion strokes had me worried.  Unfortunately, it's not something I'd be able to record as it (to me) is only noticeable while rolling, under light load usually between 20-45mph

dginfwIf your dealer is anywhere close to you, you probably should take the bike in for him or his mechanic to hear.  Make sure they ride it a block or two so they can actually hear what your talking about.  Just standing next to the idling bike won't be the same. 

They will probably say it's a normal sound but being a new engine there are some things internally that could cause that sound if the factory left out a cir-clip or something inside cracked or broke. Doing this also puts your bike on their list so if anything really does go wrong you can say, "I asked you about this and you said it was fine.  Now, please fix it." 

I'm not saying anything is broken and a leaky exhaust right at the head would be my first guess.  If it is, ask the dealer to fix it.  Then, as the others suggested, keep your eye on the area to make sure it's not loosening up. 

Speaking of loosening up, at a minimum, weekly and better than that, daily put a wrench on all of the exposed bolt heads and make sure they are tight. Big singles, especially during break in vibrate a lot and can loosen even the tightest bolt. 

If you find a loose one, remove the nut, apply some blue Loc-Tite (or other thread locking compound) and retighten it. Loc-Tite is our friend. 

The surprising thing was my bike made no loud noises and I have no idea how long it ran that way. All I noticed was it started to blow a little smoke. It died while I was on a ride, 30 miles from home.  started to blow a lot of smoke but no change in the sound of the engine until I heard a loud screech, the engine quit and I coasted as far as I could. Lost all compression. The gouges in the barrel are about 3/16" deep.  I am totally amazed that the engine ran as it did for as long as it did. So I guess the only way to really know is to open it up.