Author Topic: 400F breather cover  (Read 263 times)

Offline exvalvesetdabbler

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400F breather cover
« on: November 15, 2025, 06:11:02 PM »
What was the original finish on the 400F breather cover, painted same as rocket cover or bare metal like the sump.

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Dave

Offline Laverda Dave

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Re: 400F breather cover
« Reply #1 on: November 16, 2025, 09:51:30 PM »
From what I have been told previously only the lower crankcase and cylinder barrels were unpainted.........but of course I could be wrong!
Maybe Ash or Chris R (I don't know his username on here) can 100% confirm.
1976 Honda 400/4
1977 Rickman Honda CR750
1999 Honda VFR 800FX
1955 750 Dresda Triton
1978 Moto Morini 350 Sport
1978 Honda CB400/4 'The Flying Banana'
1982 Laverda 120 Jota
2020 Royal Enfield Interceptor 650
1990 Honda VFR400R NC30

Offline Athame57

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Re: 400F breather cover
« Reply #2 on: November 18, 2025, 01:10:22 PM »
All I know is mine was highly polished recently, that way this tucked out of sight item won't need attention for a long while.  ;)
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1978 CB400F2 called Elen.

Offline Rayzerman

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Re: 400F breather cover
« Reply #3 on: November 18, 2025, 01:30:53 PM »
Attaching a couple of pics of my CBF350 (same cover) when I got it, never been touched as far as I know.... appeared to me the valve and breather covers were unpolished metal with a clearcoat that ultimately degraded.  I had mine media blasted and painted them Honda Cloud Silver (I used the Duplicolor equivalent), same as the engine (which I also repainted).  If you were going back to original, I'd strip off the old clearcoat, sand them to say 800 or 1000 grit and clearcoat them.  Clearcoat needs something to bite into, so can't be highly polished or clearcoat won't stick.

As for the engine side covers, same thing, the originals were polished to some "grit" and clearcoated.  The clearcoat ultimately failed.

 
'72 CB350F, 2010 CBF1000FA

Online AshimotoK0

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Re: 400F breather cover
« Reply #4 on: November 18, 2025, 02:48:17 PM »
Attaching a couple of pics of my CBF350 (same cover) when I got it, never been touched as far as I know.... appeared to me the valve and breather covers were unpolished metal with a clearcoat that ultimately degraded.  I had mine media blasted and painted them Honda Cloud Silver (I used the Duplicolor equivalent), same as the engine (which I also repainted).  If you were going back to original, I'd strip off the old clearcoat, sand them to say 800 or 1000 grit and clearcoat them.  Clearcoat needs something to bite into, so can't be highly polished or clearcoat won't stick.

As for the engine side covers, same thing, the originals were polished to some "grit" and clearcoated.  The clearcoat ultimately failed.


Got to be carful there ... for instance the clutch cover is polished and clear coated on the 350F but painted silver on the 400F.

Pretty sure that the breather cover on the 400F was painted silver too.
“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

Offline exvalvesetdabbler

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Re: 400F breather cover
« Reply #5 on: November 18, 2025, 04:14:41 PM »
That 350 cover looks like an original finish and probably been nowhere near UK salty roads.

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I tried with a spare cover from a spare engine but it's a bit gnarly to polish up. I though I was ahead of the game in being able to get this cleaned up and just swap it over when I do the tappet covers and valve clearances. Would have to remove a lot of material to get rid of the gouges and chips.

Just have to hope that the one on the bike is a better starting starting position.

I have never found honda castings that great for polishing compared to say Kawasaki.

Regards
Dave

Offline Laverda Dave

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Re: 400F breather cover
« Reply #6 on: November 18, 2025, 06:17:10 PM »
Ash has previously posted photos of the original 400/4 with only 'push miles' on it and sold at auction 2-3 years ago. These photos were the 'go to' for restorers but unfortunately I think all the images may have been lost during the recent server migration.
1976 Honda 400/4
1977 Rickman Honda CR750
1999 Honda VFR 800FX
1955 750 Dresda Triton
1978 Moto Morini 350 Sport
1978 Honda CB400/4 'The Flying Banana'
1982 Laverda 120 Jota
2020 Royal Enfield Interceptor 650
1990 Honda VFR400R NC30

Offline honda-san

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Re: 400F breather cover
« Reply #7 on: November 18, 2025, 07:11:59 PM »
400/4 breather covers were not painted (nor even clear coat / lacquered that I can tell from the ten or so examples owned over the years).
I believe the original finish was therefore "as-cast", similar to sump / carbs on the same

Chris R.
Chris R.

Offline Rayzerman

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Re: 400F breather cover
« Reply #8 on: November 18, 2025, 07:35:04 PM »
The part number for the 400F is the same one as for the 350F, so.... I'm thinking it wasn't painted....

FYI the Honda Cloud Silver equivalent is Duplicolor CDE1615.

Photo of my painted valve and breather covers........






'72 CB350F, 2010 CBF1000FA

Offline exvalvesetdabbler

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Re: 400F breather cover
« Reply #9 on: November 18, 2025, 10:42:02 PM »
I decided it was junk and nothing to loose.  Started with 80 grit then 240 and 120 and then on the polishing mop with coarse compound.  Just need to do the rest of it now

The gouge is barely visible and should hopefully disappear with  a bit more rubbing with 240. Probably go down to 600 grit all over before the final polish.

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Just need a good day outside to then do the final polish all over, too messy in the garage.

Regards
Dave
« Last Edit: November 18, 2025, 10:46:17 PM by exvalvesetdabbler »

Offline ozzybud

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Re: 400F breather cover
« Reply #10 on: Today at 12:33:27 AM »
They changed up some engine finishes between the 350F and 400F the valve cover on the 350F is polished and clearcoated. The 400F valve cover is painted  cloud silver.  The breather cover appears the be as cast with no finish whatsoever. Similar changes to the side case covers.
1976 Z50 YELLOW
1970 CT70 BLUE
1971 CT70H ORANGE
1972 CT70H GREEN
1973 CL200 BLUE
1973 CB350F RED
1975 CB360T RED
1975 CB400F BLUE
1975 CB550 ORANGE
1976 CB750F RED