Honda-SOHC
SOHC.co.uk Forums => Anorak's Corner => Topic started by: exvalvesetdabbler on November 15, 2025, 06:11:02 PM
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What was the original finish on the 400F breather cover, painted same as rocket cover or bare metal like the sump.
Regards
Dave
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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.
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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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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.
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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.
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That 350 cover looks like an original finish and probably been nowhere near UK salty roads.
[attachimg=1]
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
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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.
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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.
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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........
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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.
[attachimg=1]
Just need a good day outside to then do the final polish all over, too messy in the garage.
Regards
Dave
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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.
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This is as close as I'm going to get. Taken down to 2400 grit wet with just a dash of washing up liquid.
[attachimg=1]
Just curious, what would it look like if it was now vapour blasted ? Would the texture lean towards a cast finish or look worse than it is already? Basically I'm trying to get a uniform finish that isn't too mirror like.
Regards
Dave
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Soda blasting may take that glossy look I see in your picture, or perhaps go back down to 2000 or 1500 grit. A practice piece would be good to try it on. Glass bead blasting will leave it rougher and flatter finish, and that's more intended to prepare it for paint. The raw material will oxidize, so protect it with a metal polish like Autosol or Simichrome and likely have to repeat once or twice a year.
You could clearcoat it with a matte finish, again, a practice piece would be good to try that on.
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This is a practice piece from a spare engine. Just trying out various finishes but seems to end up too shiny. Started off trying to see if I could remove a couple of scars and getting a reasonable finish and once you start .......
I'm probably going to have the sump vapour blasted over this winter because it is looking quite scabby. I'll probly include this as well and see how it turns out. The one on the working engine had similar treatment and clear coat over 30 years ago but that yellowed quite quickly. Last time around, this piece together with the rocker and tappet covers were sprayed with engine enamel and baked in the oven.
Regards
Dave