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  #1   IP: 23.240.212.74
Old 04-20-2019, 08:05 PM
ubxf ubxf is offline
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How do you change valve guides

I was told i might have to change valve guides and i was wondering how it's done because i didn't see it mentioned in the part2 of the overhaul guide. May be it can only be done by a machine shop?
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  #2   IP: 97.93.70.7
Old 04-20-2019, 09:10 PM
Dave Neptune Dave Neptune is online now
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In a "flathead" engine such as the A-4 valve guides are seldom even touched.

Who told you to redo the guides?

Dave Neptune
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  #3   IP: 23.240.212.74
Old 04-20-2019, 09:34 PM
ubxf ubxf is offline
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Thanks Dave, i asked the machine shop that cleaned the block to re-instal the valves and they said they would check everything including the valve guides and change them if they have to. Since i never heard of anyone doing that but i saw the part available for sale i was curious .
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  #4   IP: 97.93.70.7
Old 04-21-2019, 07:26 PM
Dave Neptune Dave Neptune is online now
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If you had sticky valves a honing of the guides may be in order. Are you having the valves replaced? How much engine work are you having done? Just curious.

Dave Neptune
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Old 04-21-2019, 08:28 PM
ubxf ubxf is offline
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it's a complete rebuild, i'm trying to put together an engine out of 2 broken ones.
so right now the block is bare. The valves in this one were unusable because the engine got flooded with salt water and sat like that.and the edges were badly pitted. The valves from the other engine look ok although very carbonated.
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  #6   IP: 32.211.28.40
Old 04-26-2019, 07:50 PM
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Al Schober Al Schober is offline
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I've been through a couple of engines and have never had to do anything with the valve guides. I couldn't even verify that the A4 HAS replaceable valve guides.
I have heard rumors that the folks at Universal increased the valve stem clearance for the later engines - apparently to reduce the incidence of sticky valves. No idea of from what - to what. Any other input on this would be appreciated.
If I were to do another A4 (unlikely, boat is sold & delivered), I'd consider buying the right size reamer to give the valve stem clearance I choose. Based of course on careful research.
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  #7   IP: 23.240.212.74
Old 04-27-2019, 10:30 AM
ubxf ubxf is offline
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Thanks Al, it looks like in my case honing the guides and polishing the tapets should be sufficient. I'm struggling now with the accessory gear.
one is good on the outside but rusty inside the other the opposite but i can't figure out how to swap the insides.
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