Cylinder head cover discoloration

[LongRanger_imp]

Have you guys come across this before? This cover has turned a nice copper color. I haven't seen this condition on any other CB's. I'm guessing it's heat-related but the bike runs great. Bike has about 12k miles.

 

[Lord Popgun]

Mine still look like new. How does your other one look?

 

[Ulvetanna_imp]

That cover has a different coating than the valve cover, is all.

 

[postoak_imp]

Huh, I thought that was all one piece, but according to this diagram, that is a reed valve cover that screws on to the cam cover.

http://www.partzilla.com/parts/search/Honda/Motorcycle/2013/CB1100+AC/CYLINDER+HEAD+COVER/parts.html

Have you tried some polish on it to see if that returns it to the original color?

 

[Lord Popgun]

Covers are for the PAIR valves.

 

[Ulvetanna_imp]

On my bike, 2013 standard non-ABS, that little PAIR valve cover is painted a silver metallic and has not yellowed at all. I do believe some changes were made in 2014 to finish items and other details.

 

[LongRanger_imp]

Thanks everyone. I've not bothered trying to polish it out, and the one on the other side is fine. Just looking to the forum collective to see if it's unique to my bike.

 

[BayAreaRick_imp]

^^^
Kind of like a 'birth-mark'???

 

[Gumby 1100_imp]

Thanks everyone. I've not bothered trying to polish it out, and the one on the other side is fine. Just looking to the forum collective to see if it's unique to my bike.

I don't think that you could polish it out anyway as it likely has a clear coat over the polished/anodized aluminum. You'd have to take it down to bare metal and then it might darken later anyway.

I was just wondering if those Reed Valve covers had ever been removed on your bike such as during a valve adjustment/inspection. If the reed valve was not replaced properly or was leaking, it may be possible for hot exaust gasses to travel the wrong way and heat up the cover.

 

[Ulvetanna_imp]

Thanks everyone. I've not bothered trying to polish it out, and the one on the other side is fine. Just looking to the forum collective to see if it's unique to my bike.

I don't think that you could polish it out anyway as it likely has a clear coat over the polished/anodized aluminum. You'd have to take it down to bare metal and then it might darken later anyway.

I was just wondering if those Reed Valve covers had ever been removed on your bike such as during a valve adjustment/inspection. If the reed valve was not replaced properly or was leaking, it may be possible for hot exaust gasses to travel the wrong way and heat up the cover.

I don't think that you could polish it out anyway as it likely has a clear coat over the polished/anodized aluminum. You'd have to take it down to bare metal and then it might darken later anyway.

I was just wondering if those Reed Valve covers had ever been removed on your bike such as during a valve adjustment/inspection. If the reed valve was not replaced properly or was leaking, it may be possible for hot exaust gasses to travel the wrong way and heat up the cover. Yes to all the above.

 

[postoak_imp]

If that is the clear coat that darkened, then you can remove it and respray.

 

[kmoney_imp]

Mine still looks new. As mentioned above, both of those covers are removable, so you could just get the powder in the original silver if you so desired.

 

[the Ferret]

Just looked at mine. Silver also like rest of cyl head cover.

 

[Rasher_of_bacon_imp]

I have seen gasoline stain chrome finish like that. Check for leaks from your tank or fuel lines

Sent from my SM-G935V using Tapatalk

 

[Tezza_imp]

I noticed last time I had the cam cover off the engine that there was 4 small o ring type seals that appear to be part of the secondary air supply system. Only one of them had remained in the head and the other 3 had dropped down into the fins on the cylinder head. There doesn't appear to be a mention of them in the shop manual. If your cam cover has been removed at some stage they may have fallen out allowing exhaust gas to enter the area where the discoloration is.

 

[Lord Popgun]

Those o rings are on the parts diagram though.