Author Topic: Bent valves  (Read 3044 times)

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Offline Slybones

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Bent valves
« on: August 02, 2008, 04:40:00 pm »
I got into a discussion with a guy at work yesterday, about bent valves.     - I was thinking if the valves were bent, how is the dang thing even gonna run. Maybe if just one cylinder was bad and its only one valve stuck you might get by on 3 cylinders.    - He is thinking valves can just barely bend, and that you have to check your valve adjustment to see. I thought huh? How do you do that.    -Fred.  
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Offline rowmer1

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Bent valves
« Reply #1 on: August 03, 2008, 09:35:00 am »
The only way your going to "bend " a valve is if your timing chain, cam sprockets aren't aligned properly or if your cam chain breaks. Then the piston will slam into the  face of the valve and have disastrous effects. The easiest way to check is a compression or leak down test. I guess valves that are adjusted way to tightly may also cause this. There are quite a few articles on this site about adjusting valves. I just did mine and to all those that wrote these tech articles many thanks.  

Offline PatM

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Bent valves
« Reply #2 on: August 03, 2008, 12:08:00 pm »
Quote
 I guess valves that are adjusted way to tightly may also cause this.  
   Bent valves are the result of a lot more than too tight adjusment. It's a clearance problem between the piston and valves. Too tight would vave to be way too tight as in they don't close by a wide margin to actually bend one.    Too tight usually gets you burnt valves.      Patrick    Ride safe.    1998 Kawasaki Concours Windsor Green    COG# 7292 CDA# 0135  
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Offline Slybones

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Bent valves
« Reply #3 on: August 03, 2008, 01:10:00 pm »
Yeah I have done the valves on my Connie many times now.     On a slightly different note, the manual says 6K intervals right. I did them just 3K ago and I did adjust them. 6K before that and only 1 valve was barely out and so I didnt even bother. The 6K before that and I adjusted them.    The point being that I have read that some people start switching to 12K intervals once the Connie gets some miles in her.     I am going to check them again this next time at 6K, and if there is not much change ( for the second time in a row at 6K), I too a switching to 12K intervals.  
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Offline Wess

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Bent valves
« Reply #4 on: August 03, 2008, 03:15:00 pm »
I don't know diddley but this is my plan.    Did my first at about 6500  Will do the next @ about 13K  Will follow with another @ 20K    This will give me two points where I know the settings and therefore the change.  I will adjust the mileage appropriatly.  I too have read that after 20K there is very little change.    Anytime you have the tank and plastic off is a good time as I spent more time getting to the engine than the actual adjustment.      I do have a question is it possible to do one by removing only the left side plastic?      It seems like it should.  Thanx up front for your input.  Respectfully Yours!  Wess Heavner  COG #8010 CDA #0239    
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Offline Slybones

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Bent valves
« Reply #5 on: August 03, 2008, 04:19:00 pm »
Wess, Yes and No.     I think on the right side, the air baffle has a section that sticks over the top of the valve cover. You have to remove the right side, for the most part so you can remove that air baffle, so you can get the valve cover off. And of course more room. But stock I am tempted to say No.    http://www.fredandrose.com/Concours/images/Dscn2895.jpg  http://www.fredandrose.com/Concours/images/Dscn2896.jpg    One of our fellow NWCOG members showed me a mod once, to the right side radiator air baffle that allows clearance. Assuming you have enough room to work otherwise, then YES with this little mod you could remove only the left side. As there is no need to remove this air baffle.  
« Last Edit: August 03, 2008, 04:20:00 pm by Slybones »
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Offline Rev Ryder

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Bent valves
« Reply #6 on: August 05, 2008, 02:45:00 pm »
I agree with much of what;s been said here.  Indeed, abent valve is MOST likely going to be caused by an interference with a moving object like a piston.  However, leaving a large object under the vavle cover can accomplish some interesting things as well.  :)    No I'm not the one who did it. hehe  
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Offline Steve in Sunny Fla

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Bent valves
« Reply #7 on: August 12, 2008, 07:07:00 pm »
 An engine with bent valves will indeed run. I've seen it several times. The idle will be horrible and there will often be backfiring up the intake or out the exhaust depending on which valves got it. The faster the engine is revved, the better it runs - there's less time for the compression to bleed out. Bent valves can be easily found by excessive valve clearance as well as the ordinary compression checks. steve   Shleper of the 7th gear unit and performance exhaust cam sprockets.       My bike - "SHOODABEN" - 1109cc's of what an 04 concours "shoodaben"!
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Offline Wess

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Bent valves
« Reply #8 on: August 12, 2008, 09:21:00 pm »
trying to unsubscribe.  if this is wrong let me know  Respectfully Yours!  Wess Heavner  COG #8010 CDA #0239    
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Offline Steve in Sunny Fla

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Bent valves
« Reply #9 on: August 12, 2008, 09:55:00 pm »
 unsubscribe??? was it something I said ?    Shleper of the 7th gear unit and performance exhaust cam sprockets.       My bike - "SHOODABEN" - 1109cc's of what an 04 concours "shoodaben"!
C-14 ECU flashing for performance and rideability enhancement
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Offline 2linby

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Bent valves
« Reply #10 on: August 13, 2008, 01:00:00 am »
<quote> unsubscribe??? was it something I said ?     Shleper of the 7th gear unit and performance exhaust cam sprockets.        My bike - "SHOODABEN" - 1109cc's of what an 04 concours "shoodaben"! </quote>    Oh yes you are to blame!    On the subject of intervals. Here's my story. I did the 6K thing until I hit about 24K 12-18 and 24 revealed only one to two valves off by only a couple thousandths. I went to 12K and have been doing this since. My last check at about 108K also revealed two valves off, both exhausts but within spec! I was pissed my off too! as I tore the valve cover gasket and had to deal with a slight leak using the old one before I got a new one. (Hell I wasn't not going to ride because of a minor issue like that! RTV'd the piss out of it!))  I'm at 115K so in a couple months, ;p  I'll let you know what I find at 120K.    :eg:  AKA "2linby" That's 2-lin-by folks!  Northwest Area Director  COG #5539  AMA #927779  IBA #15034  Team Oregon MC Instructor    http://community.webshots.com/user/2linby  http://tinyurl.com/njas8 (IBA BunBurner Gold Trip)  http://tinyurl.com/lwelx (Alaska trip)      
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Offline Wess

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Bent valves
« Reply #11 on: August 13, 2008, 04:25:00 pm »
It's still hitting my email so that did not work.  Can someone tell me how to stop a thread from letting you know of updates?  I am here every day so I really don't need to notified.    As always I really value the input of everyone here as you have saved me a ton of money (all of which ended up in Murph's pocket I might add).  I have already put in for Vacation to go to Nationals next year so I can thank you all in person. This is one great place.   Respectfully Yours!  Wess Heavner  COG #8010 CDA #0239    
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Offline Wizeguy

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Bent valves
« Reply #12 on: August 13, 2008, 06:41:00 pm »
Wess, on the main page of the forum, up near the top left, click where is says to View your Subscribed Topics.  When displayed, click the topic your want to unsubscribe from, then click Unsubscribe near the top center.    I think...   ;)  Mike B / Gig Harbor, WA  
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