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Main Area => General GS500 Discussion => Topic started by: GS500ERider on July 15, 2008, 05:40:30 AM

Title: Valves bent?
Post by: GS500ERider on July 15, 2008, 05:40:30 AM
Have a 91' GS500E in the shop right now. Supposedly it was ran with no oil for a short time, then the motor started to tick real loud then it was shut off. We took the valve cover off and the cams looks great, not burnt or scored. Took off the ignition generator cover to turn the crank and check the valve clearances. The motor would not fully turn over, the left intake valve appeared to be coming into contact with the piston and the engine would not turn over further. Does it sound like the valves have been bent? Thank you for any help! It is greatly appreciated!
Title: Re: Valves bent?
Post by: Mdow on July 15, 2008, 05:53:32 AM
does the motor turn at all? or does it just stop at one point
Title: Re: Valves bent?
Post by: ben2go on July 15, 2008, 06:35:08 AM
Quote from: GS500ERider on July 15, 2008, 05:40:30 AM
Have a 91' GS500E in the shop right now. Supposedly it was ran with no oil for a short time, then the motor started to tick real loud then it was shut off. We took the valve cover off and the cams looks great, not burnt or scored. Took off the ignition generator cover to turn the crank and check the valve clearances. The motor would not fully turn over, the left intake valve appeared to be coming into contact with the piston and the engine would not turn over further. Does it sound like the valves have been bent? Thank you for any help! It is greatly appreciated!



The GS engine is a non interference engine.The valves will not contact the pistons.If a valve has contacted the piston,then there is serous internal damage.
Title: Re: Valves bent?
Post by: The Buddha on July 15, 2008, 06:51:47 AM
No oil or low oil = lower end damage. heck lower end damage is possible even with adequate oil.
You may have a broken valve though.
Cool.
Buddha.
Title: Re: Valves bent?
Post by: GS500ERider on July 15, 2008, 08:32:27 AM
The owner said he could still fire the bike up and it would run, but with a "valve tick".

When you turn the engine over you can watch the piston come into contact with the right intake valve. And then you cannot turn it anymore. I'm wondering if it was actually running before?  Thank you for the help so far guys!
Title: Re: Valves bent?
Post by: Mdow on July 15, 2008, 09:13:34 AM
wait how can you watch that? you might have a valve broken off and inside the motor eather way you need to pull that thing out and tear it down
Title: Re: Valves bent?
Post by: GS500ERider on July 15, 2008, 10:25:03 AM
With the spark plug out and a flashlight shining into the cylinder, you can see the valve contacting the piston as you turn the crankshaft.
Title: Re: Valves bent?
Post by: beRto on July 15, 2008, 10:38:13 AM
Quote from: GS500ERider on July 15, 2008, 10:25:03 AM
With the spark plug out and a flashlight shining into the cylinder, you can see the valve contacting the piston as you turn the crankshaft.

:o

Sounds like this recent thread:
http://gstwins.com/gsboard/index.php?topic=42595.0
Title: Re: Valves bent?
Post by: GS500ERider on July 15, 2008, 11:14:04 AM
Uh oh, can that be caused from being ran low on oil?
Title: Re: Valves bent?
Post by: dgyver on July 15, 2008, 01:26:09 PM
One of only ways a valve can contact a piston (when hand turning) is that its valve/cam timing is off with the crank shaft.
Also, if the bucket or shim is damaged, it can push the valve deeper.
If the timing is off between the cams (18 pins is correct), the EX & IN valves will hit.