Kodak No.5 Universal Synchro difficult to CLA?

I got this shutter with a lens and it's got the following symptoms:
T and B work fine, activates snappily and without hesitation.
1/50th triggers and cycles fine, I have a speed tester but haven't set up to check this yet.
All speeds slower trigger and mostly stay open for several seconds, if the speeds even close.

I've done some basic flush and lube maintenance on a couple 4x5 lenses that ended up well. Does this Synchro and symptoms list sound like the same treatment would help revive this old dinner plate sized shutter, or is it due a pro CLA?

I'm not ham-fisted, if that helps

The Kodak/Ilex/Acme shutters are designed to work dry and oiling them can be both a bad idea and make them inconsistent. A thorough cleaning should be your first port of call. Be careful though - some of the iris/ shutter blade materials have been reported to be rather susceptible to certain solvents if you plan to simply flush the shutter. See here for a discussion of those issues - http://www.largeformatphotography.info/forum/showthread.php?16428-Cleaning-up-an-Acme-Ilex-shutter . Once running correctly, expect accuracy to within a stop or thereabouts - they're nice, simple, reliable shutters.

Sounds good, thanks for the LFF reference! My idea of "flush" is more of a squirt with a syringe and not a dip-and-dunk so I think this will work out.

Thanks!

If the blades aren't metal any organic solvent is too much organic solvent.