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Lucas oil treatment for valve seals? Xr650

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Has anyone had success with the Lucas oil treatment for worn vavle seals?? Some research on the net says , it foams in the gears and isn't good for the clutch..... I know the answer is just replace the seals but didn't know if this would be a quick fix, thanks

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Put some in my Deere mower 5 years ago and it worked great...Lucas products are excellent imo..

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Valve guides, or valve seals?  All of the old valve stem seals I've replaced have been cooked to a brittle charcoal-like crubliness.  I'd be very sceptical that any miracle oil could turn them back into pliable elastic rubber.

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U don't have to remove head to replace seals??!?? Didn't know that, what's the trick, I saw something on a thread here bout that, something bout a spring compressor

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rope down the cylinder,,bring it up to TDC and remove the springs......the rope in the cyl;inder comes up at TDC and holds the valves from falling into the cylinder........that`s the cheapy way...

 

I have an adapter from from compression guage kit made by Snap-On tools that screws into the plug hole,,then you just air up the cylinder and remove the springs with a compressor and replace the seals..

 

B

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I'd guess the air compressor line through the spark plug hole might work better than the string method.  If the string doesn't hold all the valves fully closed, it might be very finicky to get those little retainer clips back on.

 

But removing the cylinder head is pretty simple wrenching.  And usually by the time the valve stem seals have cooked, the rings and bore could use renewing too.

Edited by heart_of_darkness
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Has anyone had success with the Lucas oil treatment for worn vavle seals?? Some research on the net says , it foams in the gears and isn't good for the clutch..... I know the answer is just replace the seals but didn't know if this would be a quick fix, thanks

What symptoms make you think the valve seals are failing?

 

Are you talking about Lucas Oil Stabilizer?

 

LOS is nothing more than extremely thick oil with no additives. It impairs cold flow, promotes foaming, and dilutes the additive package of your engine oil. IMO, You would be better off trying 20w-50 engine oil (NOT from Lucas) if you aren't running something that heavy already.

 

Would you put STP or Motor Honey in your XR? Lucas Oil Stabilizer is the same class of product.

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I'd guess the air compressor line through the spark plug hole might work better than the string method.  If the string doesn't hold all the valves fully closed, it might be very finicky to get those little retainer clips back on.

 

But removing the cylinder head is pretty simple wrenching.  And usually by the time the valve stem seals have cooked, the rings and bore could use renewing too.

 

I used the "rope in the cylinder", much better peace of mind as I was concerned my compressor was not large enough to maintain pressure given possible leak down issues.  Yes, getting the retainer clips back on was a PITA with the string method, still much easier than removing the head, which is not too hard by itself...

 

I'd have to agree with the assertion that cooked valve seals indicate other issues as well.  My bike was smoking a bit at startup (cold) and when I replaced the valve seals, turned out I needed rings as well.  It was not until I dropped a valve seat that I rebuilt the top end however.

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I'd guess the air compressor line through the spark plug hole might work better than the string method.  If the string doesn't hold all the valves fully closed, it might be very finicky to get those little retainer clips back on.

 

But removing the cylinder head is pretty simple wrenching.  And usually by the time the valve stem seals have cooked, the rings and bore could use renewing too.

 

By the time it needs valve seals.........on any of these engines i have worked on,it was time to either lap the valves or do a complete proper valve job......i always pull the head..you`re right,it`s not that big of a job.

 

I have to admit to using STP in my engine after a cam builder advised me to do it for added zinc/anti wear additives......the cam ate itself to death anyway from dissimilar metals ..no other parts in the engine wore,,and the clutch didn`t seem to suffer,a friend hadv the same cam,,the STP made the clutch slip like crazy......i then went Megacycle..and threw the STP in the trash,..

 

 

 

B

Edited by brianhare

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I used the "rope in the cylinder", much better peace of mind as I was concerned my compressor was not large enough to maintain pressure given possible leak down issues.  Yes, getting the retainer clips back on was a PITA with the string method, still much easier than removing the head, which is not too hard by itself...

 

I'd have to agree with the assertion that cooked valve seals indicate other issues as well.  My bike was smoking a bit at startup (cold) and when I replaced the valve seals, turned out I needed rings as well.  It was not until I dropped a valve seat that I rebuilt the top end however.

 

I haven't tried the air compressor method, but maybe locking the crank (and therefore the piston) in the TDC position would limit how far the valves could fall inward if the air pressure dropped.  And maybe only do one valve at a time, so that you wouldn't potentially have all four valves dropping inward simultaneously.

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Oh,goody.........mechanic in a can thread :devil:

 

Seriously though,no.....in a car maybe,in a wet clutch bike,definately not..

 

B

you didnt come out of a can?

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Oh,goody.........mechanic in a can thread :devil:

Seriously though,no.....in a car maybe,in a wet clutch bike,definately not..

B

Yeah but....mechanic in a can..is so affordable..:D

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Headtrama , I'm getting smoke on decel and occasionally on cold start up if been ridin hard ride before, and I'm running 10w40 honda oil, most likely never been rebuilt since 93 when new, but seems to be a low hr bike and sat a lot, I plan on doin top end over the winter, just wanted to stop the smoking until then

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Machanic in a can? You guys must be talking about beer right? Mmmmmmm beeeeer!

 

Beeeeeeeeeeerrrrrrr ;)

 

B

And do u guys usually always so timming chain with the topend? I figured guides definitely, but chain too?

 

If it has any decent amount of miles.....yup..

 

B

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