I would say your rings are gone.

pulling the sparky without cleaning the area around it. cranking over the engine with the sparky removed. Running the engine without an air filter. Running it low on oil.  Over heating the engine.  Lots of things can cause pre-mature ring failure, These are all assuming the engine was built with the proper ring gaps to begin with.

R.F.

Another thought just entered my mind since I saw how many miles was on it when you bought it, and how little you have on it now as well.  Did you do an oil change around the 500 mile mark, to get rid of the break in oil? It's common that the first oil in new motors gets contaminated really quick as it's cleaning out casting sand and other machining debris that was not able to be washed out.  This could also cause additional accelerated wear in an engine. That is why they recommend a first oil change at 500 miles.

R.F.

Also running with the choke on for extended periods.

And maybe the rings were never broke in correctly.

How about putting the rings in and measuring the gap?

Thanks for all your sympathy, support and suggestions.  Yes this does really suck in the middle of riding season.  I bought a newer, low mileage bike so I could ride and not have to wrench.  I am horribly busy at work during the summers.....and this was supposed to be a low maintenance bike!

The bike came from Long Island and based on the experience I have when I went to pick it up.......It was not driven in any dusty conditions.  The bike probaby spent a lot of time stuck in traffic, and it idled a lot at traffic lights and probably never saw much open road action.  The woman I bought it from was dating a biker and was learning to ride - but then they broke up and she had no interest in riding anymore.  I believe the mileage is actual as the bike was very clean and the tires and drive belt showed no wear.  The air cleaner and the housing are very clean....I did have it on a dirt road on the Dragon trip but I rode off to the side of the fellow in front of me and didn't get too dusty except for the rear wheel and swing arm.  The top of the cylinder head has always been clean from what I can tell, and I doubt that any dirt fell in during a plug check or change.

I am an oil change Junky during the break in and I changed the oil immediately after getting the bike at 262 miles, then again at 400 miles and again about about 800 miles.  I made the change at 800 to see if using 20W-50 might help to make it less noisey.....the temperature around here was in the 90-100 range during that period.  The oil does not show any metal bits and comes out pretty clean at those intervals - the oil in the level window was always honey colored.  I used Suzuki 10W-40 for the first change and Valvoline 20W-50 motorcycle oil for the 2nd change.  The bike never made any noticeable smoke out the exhaust, and I never noticed any oil consumption.  I wish I had done a compression check before tearing it down.

The ring end gap measures 0.020.  The Clymer manual shows the installed range to be 0.012 - 0.018, and the wear limit to be 0.039.  My rings appear to be nearly new from a clearance perspective.  I have a friend that is active with the KLR650 crowd and a good motorcycle mechanic and he has raced and worked on road race bikes for years.  He says that Suzuki has a problem with the ring seating in their big singles.  I have never seen that comment on this forum......but I have seen it on the forums for the other Suzuki singles and even seen people report on Warranty repairs to correct it.  They are not sure of the cause buy claim ring flutter or out of round cylinders might be a cause.

I am not sure of the scoring issue.  It is very minor, and in my chainsaw experience there can be a problem with carbon scoring when the engine is run too rich or with too much oil.  The carbon can come loose and get along the cylinder wall/piston clearance and cause scoring.

I have no problem honing the cylinder to clean it up and getting a new set of rings......might as well clean up the head and replace the valve seals while it is apart.  I am still looking to find the source of the knock however......I don't yet understand how these cylinder issues would have caused the engine clack/knock that I was having. It sounded like piston slap at idle and detonation during hard acceleration.

 
Not me, Kemosabe.    Both Lancer and I looked at his bike up at the Dragon, and he has a very sharp heavy knock sound coming from the lower end (right side).

Dave, I never said head area, I never bet on piston slap, I said counter balancer bearings or crank bearings (big assed failed ball cage ball bearings) and those items are all in the lower end of the engine.    To find these things you are going to have to split the cases and do a FULL engine tear down.   Sorry.

Some others might have made hopeful head/jug noises, but t'warn't me what sent you off on a hopeful rabbit hunt to the head/jug area.
(although you do have to take them off to get to the cases)

Lancer, did you send him off on a rabbit hunt into the head/jug area?

I also suggested that you get a mechanics stethoscope and search out the exact origin point of the big heavy knock sound before taking the bike apart.

Verslagen, tell the man all about counter balancer bearings losing the ball bearing cage and making a heavy knock sound on acceleration.   I think you know more about that than I do since you dealt with it directly.



Now, what's really really sick about the whole thing

His bike is practically brand new ....  should have been a warranty issue if the original owner had got off her ass and had taken it in to the dealership inside the first year.  

But she didn't.   She never ran it hard enough to even seat the rings and she ran the idle speed running way down low too.

If you could prove that she did take it in and the dealership bullshitted her that it was "a normal big single sound" then you could protest to Suzuki USA and perhaps get somewhere.  

Especially if they were the ones that set up that low idle speed for her to putt around with inside New York City.



(How were your head cam bearing journals?  If there is no galling of the aluminium then the low idle speed did no damage and your oil pressure may have been OK after all)

Oldfeller--FSO wrote on 07/15/12 at 05:01:07:



I am not only looking at the head/cylinder/piston......I just thought the carbon and wear were unusual for a bike with so few miles and need to fix that issue....but as of last night I had still not found anything that I thought was a blatant cause of the knock.

With the engine down as far as it is I can pull see all of the bearings and races on the balancing shaft and they look great and I cannot get any movement from them.  The right side crank bearing looks great and I cannot get any movement, and the rod shows no movement up or down or twisting and only has a small amount of side play.

However.......this morning I placed the engine on the floor and put my knee on top.....and if I pull up and down on the (left side) alternator rotor I can feel and hear a slight clunking noise.  At first I thought maybe it was the mounting of the rotor.....but if I pull up and down on the center shaft I can still feel the movement as well.  I am going to go out and put the dial indicator back on the left crank throw and see if the movement is measurable on the crank, and also check the tightness of the alternator rotor.  Is there any method to get the rotor off without buying the puller?  Anyone have one they can rent to me, or do I just need to drop the engine off at the dealer for them to pull the rotor for me?

The oil pump seems to be doing OK.  When I pulled the engine apart there was a pool of oil in the well where the cam lobes dip, and the cam seems to be getting plenty of oil as it still has not worn the black oxide coating off the bearings surfaces.