Hello everyone.

Unfortunately, my GS has broken down on me recently (so much for a summer ride). I was on my way up to my base when my bike suddenly had a loss in power. Wearing earphones and a helmet, I was unable to hear any abnormalities until I had pulled over off of the Mass Pike. Upon taking my helmet off, I noticed a consistent pinging coming from the engine, and immediately shut if off out of fear further damage.

My conclusion was damage due to a combination of the following:
-No valve check within past 8k miles
-Oil was about 200 miles from being due for an oil change
-Possible low oil (overheating)
-Improper oil weight? (was using 10w40, also could contribute to overheat)

I have since started a complete breakdown of the bike and engine. Starting with the top of the engine, I've checked the following:
-Camshafts, including lobes for wear and camshaft ends using dial indicator
-Valves. Cleaned them all up, checked for wear, look good. Only odd thing that stood out was the right exhaust valve being white. After a bit of WD40 and brushing, it still looks fine. They all slide out easily. Haven't checked them or the slides with a dial indicator yet though. Also haven't checked the shims yet (I'll check them last when I reassemble)
-Pistons. Lots of carbon, but after a cleanup they look fine. Left cylinder's top ring wasn't moving around. checked thickness and it was 0.0484 inches, out if range by about 0.002 inches.

So far nothing seems out of the ordinary, but I'm completely lost right now. About to tear open the crankcase tomorrow (although I'd rather not have to).

Any words of wisdom would be greatly appreciated.

Also, does the gs500 have a pcv valve?

my guess is a spun bearing on the main crank..at the bottom.
Can you tell where the noise was comin from? top or bottom?
-CS

#5146

Before opening up the case, take off the right side cover. I had a counter balancer bearing go out. Made a terrible racket.

http://www.youtube.com/watch?v=Atq4nKfh7kg&list=UUfopOgFUP9aRZNHRZ8GAXeg&index=4&feature=plcp