How many miles do you have on the bike?

From which side is the noise the loudest?

Up high?

Down low?

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Remarkably little info was given to you to try to help you with.  

Your stealership didn't tell you anything, just told you it was going to be very expensive.  They don't really know anything, they are just trying to get the bike into their clutches for a teardown analysis that will cost you $$$$.

Fine, take a foot or so piece of tubing and put it to your ear and use the other end to search out which side and relatively high or low for the source of the Knock sound.  If you have an stethoscope that would be nice too.

Knock sounds can even come from the long engine mounting bolts that run through your peg mounts getting loose letting the entire engine move during acceleration.

Use the tubing and find out roughly where the sound is coming from as the very first step to not spending $500 plus dollars at your stealership.

Got a pm from the man that says the noise comes and goes.  He can't find it with a screwdriver held to his ear.  Never could get that screwdriver trick to work, always used a piece of tubing myself.  Never got any clearer indication of a "where" any better than right side, left side or high up or down low anyway.

Still don't know how many miles are on the bike, so I'd say tighten up the motor mounting bolts as a easy gimme and then check the cam chain adjuster if it is over 12,000 miles on the bike's odometer.

Change the oil, look for metal, easy stuff.  Other than that, mystery noises that are bad things get worse over time.  Eventually they will get to the point they define themselves clearly.

I have never read a thread about crank, rod or main bearings going bad on our Savages.  The stealership is simply BS'ing you on that one, shame on them.

I have read lots of knock stories, things that were off the wall like the small belt sprocket pulley getting loose and the speedo clunking loose inside the gas tank.  There was a knock sound associated with a clutch assembly one time, that one depended on if clutch was in or out.  We got lots of reasons for motors to make a noise (and some have been doing it for a long long time too).

I had to fix my speedo noise and have personally had my motor mounts get loose and scared me with a deep infrequent knock sound that totally ended when the loose motor mounting bolts were tightened back up.

Heck, your headlight can rattle too, but it can't make a real knock sound I don't reckon.  

But what is a rattle to me might be somebody else's "knock" to them.

Heck, the engine itself naturally makes a sorta heavy knock sound of sorts every time you goose it too hard with the rpm too low due to being in too tall a gear ...  I think it is a form of detonation knock of some sort when that happens.  

And it will, every time you do that sort of "lug it low and goose it" stuff in the lower gears.  I have watched my gas tank move back and forth in the rubber mounts many many times when I was making the big single "thump" hard on purpose.

Bad gas has made a nasty rattle knock for an entire tankful one time.

I guess the point is a knock can have many causes, none of which are grounds to give the bike over to a stealership and sign yourself up for a big repair bill for an "undetermined cause", especially when they have indicated a willingness to BS you with a never before seen bearing failure.  

Live with it for a while before blowing any money like that -- even if you aren't a wrencher it makes good sense to at least know what your issue really is before giving it over to the stealership and bending over the repair table while they have their way with you.

Depending on the mileage, Id start with looking at the tensioner. Thats a dangerous issue. That can destroy an engine in a split second, so, even if it shouldnt need looked at, I believe an unexplained noise needs looked into right away. I would start in the place that could be fatal for the engine. But, before I did that, I'd tighten the motor mounts & look at the belt pulley on the left side of the engine.

Is it possible this "Knock" that comes & goes only shows up under hard acceleration , from low speeds & the bike in 3rd gear?

didn't mean to say it completely goes away, tends to come and go. as for the cam chain it is the original, tensioner is original also.

Well, he did get the part about the oil.  So something sank in.

And we all could aspire to have our cam chains go 33k.

So what was it?  Why you?