Author Topic: valve stuck?  (Read 971 times)

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Offline robnola44

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valve stuck?
« on: June 14, 2016, 06:34:09 PM »
i suspect i might have  a valve stuck open in cylinder 1 but was wondering if there was any way to unstick it without tearing the head apart. Ive heard running seafoam works or marvel mystery oil but idk for certain. does anyone know of anything to help unstick a valve?

Offline alacrity

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Re: valve stuck?
« Reply #1 on: June 14, 2016, 07:28:48 PM »
i suspect i might have  a valve stuck open in cylinder 1 but was wondering if there was any way to unstick it without tearing the head apart. Ive heard running seafoam works or marvel mystery oil but idk for certain. does anyone know of anything to help unstick a valve?

Funny you should ask, Rob.  I posted this the other day:

http://forums.sohc4.net/index.php/topic,158286.0.html
I recently restored and sold a 77 cb750f, and am nearly finished with a (former basket case) cb750k5.  This is a place to share, learn and enjoy.  I am grateful to and for 99+% of this site's membership.

Offline robnola44

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Re: valve stuck?
« Reply #2 on: June 14, 2016, 08:17:51 PM »
i suspect i might have  a valve stuck open in cylinder 1 but was wondering if there was any way to unstick it without tearing the head apart. Ive heard running seafoam works or marvel mystery oil but idk for certain. does anyone know of anything to help unstick a valve?

Funny you should ask, Rob.  I posted this the other day:

http://forums.sohc4.net/index.php/topic,158286.0.html
thank you!!!

Online Don R

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Re: valve stuck?
« Reply #3 on: June 14, 2016, 09:17:55 PM »
  If it runs, give marvell mystery oil a shot. I've used it on flathead fords and even a chevy V8 with a sticky lifter. Worst case you spend a few bucks and nothing happens.
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Offline robnola44

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Re: valve stuck?
« Reply #4 on: June 16, 2016, 12:57:42 PM »
  If it runs, give marvell mystery oil a shot. I've used it on flathead fords and even a chevy V8 with a sticky lifter. Worst case you spend a few bucks and nothing happens.
put alittle right in the spark plug hole right? or do you run it in the gas? ... never used it

Offline alacrity

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Re: valve stuck?
« Reply #5 on: June 17, 2016, 02:24:51 AM »
some guys find the marvel oil works great  - others like seafood. I like both/either WHATEVER magic goop will maybe help (for a few bucks a bottle) and save me a ton of time/money and not cause more problems.

SO - think of what you are trying to "cure" - potential "sticky" valve.  Where is it likely to be sticking? Well, where is it trying to move? Up and down in the valve guide is where, and there is a little bit of oil that gets in there (very little)  - just what adheres to the valve stem as it slides up into the oily mist in and around the valve springs and then is shoved down past the valve stem seal (through the guide of course) until fully open, and then back again.  So ... answer your own question (yes I am being pedantic here). Where would the logically correct place to put an ounce or so of either liquid for this suspected problem?
I recently restored and sold a 77 cb750f, and am nearly finished with a (former basket case) cb750k5.  This is a place to share, learn and enjoy.  I am grateful to and for 99+% of this site's membership.