Savageman wrote on 05/16/16 at 14:44:25:


Oh yes, that axle seal. Saw it and noticed that it's very_slightly_ slanted, tried to push it straight but it wouldn't move so left it like that. Seemed fine otherwise.

What's its purpose? To seal something, obviously   Is there a oil passage inside that axle or does it just keep the oil inside? Can't really remember which side up it was there, maybe I'll pull the clutch cover and check that it's not seated wrong way around.

justin_o_guy2 wrote on 05/16/16 at 13:16:07:

the newer oil filters have been redesigned, I think, the first time I changed my oil, I had to be careful not to put it it back'erds, the 2nd time, the filter would not have been installable the wrong way round
Maybe Suzuki got tired of replacing motors mechanics at the dealer blew up

OK, drove it a bit with no change in the noise. Pulls really nicely  

I inspected the audio file visually and the noise appears 852 times a minute. So that leads me to a conclusion that

-idle is adjusted too low
-can't be a con rod bearing as it would tap double as much, wouldn't it?

Next I'll check the compressions and look inside the cylinder with a borescope, if there's nothing worrying there then I'll have to order some plastigauge and check the cam journals.

I'd use a good old fashioned stethoscope on the cylinder. It sounds like piston slap to me. Loose piston in the cylinder.

You would hear it more pronounced during ignition. So the same speed as the cam. Every 4th stroke at the power stroke. Compression stroke, spark/power stroke makes the piston skirt rattle on the cylinder wall. If that's it. Could be valve timing jumped out a notch or 2.

justin_o_guy2 wrote on 07/27/16 at 13:30:38:


I'm going to do it all by myself, with a little help from my friends  

https://www.dropbox.com/s/yvxuaovxpnrhyco/2016-07-28%2016.32.20.jpg?dl=0

Engine removal took us 3 hours, before that I had a chance to properly drive the Savage first time. Have to admit that it's quite nice bike  

The noise is most present when the motor is under load, while engine braking it's perfectly healthy sounding. On the startup the engine sounded perfectly fine too, but after a minute or two of warming up the clanking was there and refused to go away.

I hope it's piston slap, then I'll have a 666cc Green Machine  

Most engine manuals recommend wrist pin clearances between .0008 and .0010-inch for conventional engines; my advice is to run .0020 to .0022-inch wrist pin clearance in a serious drag racing engine.


http://rehermorrison.com/tech-talk-49-wrist-pins-and-unintended-consequences/


If you're able to call it sloppy, it's probably not in spec.
It's not Just the clearance, is the hole round?
Are the piston holes the same size and shape?
Is the connecting rod hole the same size on both sides?
How much slop in the pin and con rod? Can you tilt it?
Running a micrometer on each end and center and the length between end and center, how is the wear?

Dial calipers are better than nothing, micrometer is better.

The wrist pins job is to stop the piston at the top of the exhaust stroke and drag it down for the intake stroke. If it's worn in the piston/ pin/ rod areas, it's Gonna be noisy on that stroke.
When it gets to the bottom of the intake stroke, it's gotta stop the piston and head into the compression stroke. Worn holes and pin equals Clack. Turning around at the top of compression, no clack, turning around at the end of the power stroke, no clack,

Get the crank poking the rod up as far as possible and play with it. Feel for slacif you pull or push. Lean it left and right, gently, don't Try to wreck the bearing. Twist, push, pull, gilt.
Without knowing How loose the wrist pin is, nobody can know if it's okay

Savageman wrote on 07/28/16 at 19:59:23:


I don't believe it is possible for the cam chain to jump teeth on this bike.  If someone had the engine apart previously...they may have assembled it wrong.  It could also be that the wrist pin is loose enough to allow the piston to move around too much and contact the valves.....or that somebody over revved the engine and floated the valves.

Kojones.....Can you take a picture of the top of the piston for us?  Was it only the exhaust valves that touched, or the intakes....or both?