Hi, I'm brand new to the site and new to motorcycling in general.  I recently picked up a 2008 S40 with only about 5000km (3100 miles) for a great price in not running condition.  It looked great and has low kms so I figured I'd take my chances.  I quickly found that it had been massively overfilled with motor oil.  I found a cup or so of oil pooled in the air box and the air filter saturated with oil.  I've got a new air filter coming in the mail.  I drained over 4 litres (about 4.5 quarts) out of it!  I'm guessing it was filled to the top of the fill plug.

Since the bike is new to me, I checked out a few other things.  Drained the fuel and replaced it with fresh premium.  Changed the plug and confirmed good spark.  Checked the compression and measured a little over 100psi.  Checked valve clearance - I had trouble getting the feeler gauges in but confirmed qualitatively that there was a few thousandths clearance.  Drained and removed the carburetor bowl and found everything looking really clean.

I put it all back together (with the right amount of oil) and it fired right up.  It seems to ride well, but I don't have much to compare it to.  

What concerns me is a really high pitch sound that seems to be coming out of the exhaust (stock).  It sort of sounds like a whistle, but sort of also sounds like metal on metal rubbing.  It's loud during the first turn when I start the engine, but it generally is continuous.  It's louder as RPMs are slowing and less loud when reving it up.  Any ideas what this might be?  Could it be linked to the overfill of oil?  There's no indication of blown seals (no oil oozing out anywhere) and I think the compression is good, right?  Should I be worried about the oil pump?  Anything else I should check?  It sounds like the previous owner had run it more than just a little since the last oil change.  They said one day it backfired and wouldn't run anymore so they trailered it home and put it up for sale.

As Serow said, the overage of oil in the crankcase and oil in the air box, denotes a faulty fuel tank petcock, keep a close eye on your oil level, if it starts to climb in the window (getting more full without adding oil), it means gas is venting into the crank case.

The savage/S40 is known for the infamous "backfire" on shut down and throttle blips, its is ok if this is happening. You can lesson the backfiring a little, just read in the Tech section or do a search for "backfiring".
I would also do some reading on the "raptor" or "petcock replacement".....

Do you know how to attach a video? It would kinda help if we could hear the squealing.

Some folks idea of a loud sound is different than others, much like my "loud clacking" of the valves is actually quieter than others, I found that out at our texas meet.

Thanks a ton for the input guys.  I should have thought to attach a video of the exhaust sound.  I've tried attaching one...Hope it works.  Is this the "VW" sound you're referring to?  It sort of sucks.

RE the whistle: I just completed a 900 mile putt this weekend across western New Mexico and eastern Arizona. Half way, after a HOT day I discovered a "whistle" at idle that decreased when I revved it.  Loose header collar bolts were the cause. Tighten and all is good....

justin_o_guy2 wrote on 09/14/15 at 09:58:39:

It wuz by the time I could locate/ borrow a 11mm socket.    (Silly Texas chicken rustler... I'm old, NOT from Texas..)