Bent valve-guide question

[uclabiker06]

Is this a proper method to detect a bent valve guide?  Or would a compression test be the correct thing to do.  I can't tell because its not in English. 

http://www.youtube.com/watch?v=KRfTuHt6FEQ

[Hedgehog]

That's actually checking for a worn valve guide.  But, I wouldn't use a pair of pliers.  That will knurl up the valve stem.  Just use your fingers and if it obviously moves, there may be a problem, depending on how much it moves.  You'd have to check the manual to see what the limits are for guide wear.  Generally you only need to worry on a very high mileage engine.  For example, I had to change the guides on my old Porsche 911 at a bit over 100,000 miles.

[uclabiker06]

For example, I had to change the guides on my old Porsche 911 at a bit over 100,000 miles.

Wow, thats cool.  When that happens to my Monster it will be time for some titanium.  Looks like the valve in the video is indeed worn.  Thanks. 

[He Man]

You cant just use the stronger metal. It has to expand (heatwise) with the rest of the engine. So im not sure if Ti guides will work. My guides are worst than that. They have a total of 1/2+ inch movement. Its apparently a common issue on Ducati DS1000 engines. Bikes going in to the shop to get them replaced under warranty.

[uclabiker06]

Yeah its actually "common" on the S2R800 also. 

Just use your fingers and if it obviously moves, there may be a problem, depending on how much it moves.

Just checked my manual and it says the clearance for the valve guide is .03-.06mm.  Seems like it would be difficult to tell if the clearance was only a bit out of spec like .09mm.  Is there a specific tool to help out?  Can feeler gauges be used?  1/2inch is definitely way off.  When did you first notice that your valves were bad? 

[He Man]

feeler guages wont fit. I dont know how you would be able to tell technically, but you cant really feel a hard thump when you wiggle .03mm, you can physically see .09mm move though.

I first noticed my valve guides were worn when i did my 6000 valve adjustment at 6200mi. It was probably a prexisting condition since i did notice a bit of oil on the valve covers when i first bought the bike with 4444mi.  I assumed it was just a valve gasket. but the oil started getting worst as time went on. All you do is wiggle the valve guide with your fingers and you can feel it. Im not sure if mine are worn to hte point where i would need custom guides, or OEM guides could be installed. Nicholas sells valve guides for $20 a pop.

Ducati revised their valve guides mid 2006. My bike is an 06, but i guess i wasnt lucky enough to get them. Either way, i hope they dont have an issue with DNA.

[Ddan]

I think the .03-.06 spec is for valve guide to valve stem clearance.  You measure the stem with a mic, the valve guide with a small hole gauge and a mic, and the difference is the play.  I would expect there to be no play at all in the valve guide to the head.

[He Man]

I think the .03-.06 spec is for valve guide to valve stem clearance.  You measure the stem with a mic, the valve guide with a small hole gauge and a mic, and the difference is the play.  I would expect there to be no play at all in the valve guide to the head.

I assume there should be none since its pressed into the engine block.

[uclabiker06]

Nicholas sells valve guides for $20 a pop.  Ducati revised their valve guides mid 2006.

Wow, mine is an '06 as well and I had a leaking front exhaust cover at 4500K.  I tightened the cover and have had no issues since.  Why did they revise their valve guides?  How do you know that they revised them?  Man that sucks.

I assume there should be none since its pressed into the engine block.

Okay, so I just grab the valve and wiggle it around and if there is any movement like in that video then my guides are bad??  I was really hoping to avoid the dealership but now I just don't know. 

[He Man]

They are machine pressed in, so i dont see why there can be any movement. If you have warranty, USE IT. If you dont, and its expired recently, perhaps you can get it good willed since it is something that is casued by bad engineering and developed as mileage racked on.

As for an leaking cover, it can be anything from a bad gasket to a worn valve guide. Ultimately if you dont fix it, it gets worst and worst and the valve starts moving which can cause it to bend over time.

As far as the new guides, its just from talking to people and mechanics. That old valve guides werent doing to well since alot of DS1000 engines were shitting them, so they made new ones. The dealership i am going to sends as many as 1 or 2 engines a month in for valve guide replacement. the majority of them are ds1000 engines too.

[uclabiker06]

I don't trust the dealership so I don't like them touching my bike.  But I will be taking it in to an unauthorized mechanic for the 6K checkup before my warranty comes up.  If there are bad valves then he will button it back up and it will go to the dealership to get valve guides fixed under warranty.  Hopefully they wont give me a hard time about the warranty work since I didn't have them do the 6K checkup.  I just wish there was a sure way I could diagnose a worn valve myself.

[Howie]

Why do you think you have a worn valve guide?  What are the symptoms?  The method described by Dan is the best, but there is an alternative that requires less surgery.  Of course, caution is needed to inure the valve doesn't fall into the cylinder.  Turn the engine over until the cylinder is in position for measuring valve clearance.  Remove the helper spring and move the rocker arm over just like you are changing a valve shim.  Set up a dial indicator in the same plane as the rocker arm.  Ideally you should remove the valve guide seal, though I would leave it.  Wiggle the valve.  That is your clearance.  If you have an newer engine with smaller valve stems Dan's .03-.06 might be a little generous.

If I trusted my dealer that little I would take the bike somewhere else, even if it meant transporting the bike a few hundred miles.  If the dealer can't be trusted ti to the diagnosis I sure wouldn't want them touching the insides of my engine.  Think of your mechanic as your motorcycle's doctor.

[He Man]

Why do you think you have a worn valve guide?  What are the symptoms?  The method described by Dan is the best, but there is an alternative that requires less surgery.  Of course, caution is needed to inure the valve doesn't fall into the cylinder.  Turn the engine over until the cylinder is in position for measuring valve clearance.  Remove the helper spring and move the rocker arm over just like you are changing a valve shim.  Set up a dial indicator in the same plane as the rocker arm.  Ideally you should remove the valve guide seal, though I would leave it.  Wiggle the valve.  That is your clearance.  If you have an newer engine with smaller valve stems Dan's .03-.06 might be a little generous.

If I trusted my dealer that little I would take the bike somewhere else, even if it meant transporting the bike a few hundred miles.  If the dealer can't be trusted ti to the diagnosis I sure wouldn't want them touching the insides of my engine.  Think of your mechanic as your motorcycle's doctor.

+1 checking for worn guides is very easy. You can defintely do it yourself, but if you were going to get him to do the 6k, then just make sure he knows you are specificly looking to see how loose they are (if they are loose at all) My local dealer is less than 15minutes from me. I dont trust them. Im actually riding out almost 100miles and taking the train home. And i did the same thing you did, brought my bike in for valve adjustment at a non dealer (european cycle services, 100 miles from me) and mid way, he noticed how loose they were.

[uclabiker06]

Yeah I'll just let my mechanic know to check them before he gets started on the valve clearance.  In the meantime I will take off the valve covers and "check things out" to familiarize myself with the valve system.  I think I am just over thinking this.  Thanks to all for helping to ease my mind.