Hey there, I recently bought a 2004 Suzuki Savage LS650 for a bobber project, it was a very clean bike with 19,000 miles and I paid 900 dollars for it.

All is good, I have changed out the cam chain tensioner, changed oil, and performed the valve check. All these things have definitely improved the bike, but it has a terrible knocking noise, almost sounds like it is coming from the jug. The knock is most noticeable when the bike is under load, I mean it is a clang clang clang clang.

Is anyone familiar with this, I know character engine sounds when i hear them and this is my third savage, but this sounds like knocking on something solid...

You installed a Verslavy tensioner?

You didn't answer the question..

Two of the forum members on this site (and I am one of them), have been fooled into thinking we have serious engine problems....and after tearing the entire engine down to the cranksahft - have learned that the flywheel nut have loosened.  The flywheel and crankshaft joint is splined, and at low rpm's the darned thing bangs and rattles horribly.  The noise is somewhat of a "clank" sound with each power pulse of the engine.  As the rpm's increased the noise is somewhat reduced as the power pulses are more even, and at a high cruise speed you really can't hear the clanking over the road noise.  The noise is hard to locate, as the left side of the crank does not touch the left side of the case...the clanking noise goes through the crank bearings into the case, and then can travel up through the cylinder and resonate through the fins.

The bad news about this, is that it is not all that easy to check.  You have to removed the left engine cover, remove the rotor with the special puller, then you can access the flywheel nut.....you will need a large deep socket and a holder for the flywheel to torque it to the 100 ft. lbs that it requires.  I would first check and see how tight it is.....in both instances that this noised showed up the nut was finger tight.  I would remove the nut and clean all the threads to remove the oil, and then install threadlocker when you install it and torque it down.  You will most likely need a new gasket, and be careful with the washers on the starter torque clutch - a washer will be on both sides - with no washers on the other idler gear next to the starter.

I had a different clunk, probably typically called piston slap.
the piston had burned and squeezed down on the rings.
Still ran, couldn't find the cause till we tore it down.
the small burn spot was visible from the top, if you had 1 of those eyeballs on a stick that'll fit inside the plug hole.

I had a clanging noise that was intermittent and when it occurred, it caused surges in power. It sounded like it was in the engine, but it turned out that a baffle in the muffler had broken loose and the clanging sound would resonate off the fins. At times, it would get wedged in the muffler, not make noise and the engine would run great. At other times it would get wedged sideways in the muffler and almost "choke off" the exhaust.

I got the baffle straight drilled 3 small holes in the bottom and back of the muffler and inserted 3 sheet metal screws. It worked great for about 800 miles, then the same thing happened. I tried stainless steel pop rivets and they lasted about 1k miles and then I tried 1/4" self drilling screws and they lasted about 2k miles. My final solution will be to cut open the muffler and weld it in place.  

All that to say, that everyone who heard it, thought it was a terrible engine problem, but was not engine related at all.

Relax just a little bit,... I remember that guy...
He had welding on some balance weights that came loose and disintegrated...

You haven't welding behind our backs, have you?.... ...


... might have been, Phelonious?...

justin_o_guy2 wrote on 03/18/15 at 16:37:13:

I think it was phelonious, or the other guy in WA

decided to add a weight to the inside of the wrist pin so the high compression piston matched weights with the stock piston.
weight came loose and jammed into the cylinder.