Author Topic: How bad are these valves?  (Read 4240 times)

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Offline dave500

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Re: How bad are these valves?
« Reply #25 on: November 24, 2018, 11:41:14 PM »
ha ha ha no!!!!I don't #$%* around with tiny rubber suckers and twist back and forth between my palms either,stick some hose in your battery drill,jam it over the valve stem and apply pressure pulling back and also with a finger on the valve head,dont spin the #$%* out of it use medium speed and reverse it for the same amount of time,job done!

Offline seanbarney41

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Re: How bad are these valves?
« Reply #26 on: November 24, 2018, 11:44:21 PM »
Is that a 650 head?
If it works good, it looks good...

Offline dave500

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Re: How bad are these valves?
« Reply #27 on: November 24, 2018, 11:46:54 PM »
no 500/550,i have it for sale.new guide seals and head gasket supplied,ports touched up.

Offline dave500

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Re: How bad are these valves?
« Reply #28 on: November 24, 2018, 11:52:50 PM »
basically just had the exhaust floor levelled out so you can see the seat clearly,i never do much on the intakes just clean up any obvious casting dags.

Offline seanbarney41

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Re: How bad are these valves?
« Reply #29 on: November 25, 2018, 12:12:41 AM »
ok, guess I never noticed how finned up the 500/550 heads were
If it works good, it looks good...

Offline dave500

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Re: How bad are these valves?
« Reply #30 on: November 25, 2018, 12:28:28 AM »
that's another thing,a lot off the air passages externally have crappy cast break away,leaving half or fully blocked airways,i break them though and tidy them up at the same time,any old damaged fins get cleaned up sharp edges etc,takes a coupla days.

Offline PeWe

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Re: How bad are these valves?
« Reply #31 on: November 25, 2018, 06:32:37 AM »
A tool for valve removal- assembly is rather cheap.
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline gmog44

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Re: How bad are these valves?
« Reply #32 on: July 04, 2020, 11:46:43 AM »
Valves lapped per dave500’s drill method: I am afraid to go too far, although the exhaust valves need more... or is it too late? Replace?
'78 CB550
'72 CB450

Offline MRieck

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Re: How bad are these valves?
« Reply #33 on: July 04, 2020, 02:33:35 PM »
 The 45 degree face is troughed and notably pitted. Replace them. Many Honda OEM valves are soft to begin with.
Owner of the "Million Dollar CB"

Offline gmog44

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Re: How bad are these valves?
« Reply #34 on: July 05, 2020, 01:07:30 AM »
That’s what I feared, thanks for confirming. Replace them I will.
'78 CB550
'72 CB450