Bad Cylinder Head? Bad Casting?

[beesumpa]

On my 2004 Rockster the power coat bubbled up - literally like a paint blister. It is the blueish powder coating and with it comes off some of what almost looks like sand stuck to the coating - My thinking is it is a bad cast an manufacturing failure - what are you guys thinking and has anyone ever run into this? I did not realize it until this weekend during routing cleaning I pushed to hard to get some bugs if that spot and that bubble cracked. Any suggestions?

[sweatmark]

Bad paint, or painting/cleaning/preparation process. Many of our Rocksters have exhibited the same blistering on both the valve covers and Telelever parts which share the same paint.

Different remedies are possible, including repainting the flawed parts with similar color or black - which is my plan for valve covers this winter.

[beesumpa]

Guess will take off the valve covers and get it powder coated.

[Laserr Boy]

My left side cover did the same thing complete with the bubble and the powdery stuff inside. When I had mine powder coated the guy who did the work reckoned that a combination of a rough casting as well as bad prep caused the failure. It seems the casting was rough and it looks like they tried to use a heavy powder coat to smooth it out. Mine were done in the spring and still look very good, the coating is thinner than the stock colour.I have not noticed any other spots that have the bubbles.

[AndyRR]

I'm a fan of the matte black grill or engine paint. Powder coating is great, but sooner or later your cylinder head cover will touch down. If you have the can of paint on the shelf, touch up is a breeze. I used ceramic engine paint after thoroughly cleaning and scuffing the surface. Never found an easy way to remove the head cover bolts, so I just taped them. That paint has held up very well over about 30k miles or so. Total cost - less than $10. I also painted the rusting gray fairing mounts and a helmet with the same can.

[Jpainter187]

My left cylinder head did the same thing. I just got a needle and popped it while the engine was hot and slowly pushed it back down until it settled, then let cool. Haven't noticed it since, knock on wood.

[beesumpa]

Yeah I was not that smart with using a needle I popped it by accident cleaning it and it simply cracked was the size of a quarter elliptic, so once it cracked that was that. I would expect something different from a company like BMW - very disappointing.

[beesumpa]

Mine is left as well - seems there is a pattern here. I have an engine guard on the bike - cylinder guards to it bubbled right above it.

[boxermania]

None of the engine parts are powder coated at the factory, they are painted. The problems associated with the bubbles and peeling are bad prep (dirty/contaminated surface) prior to the paint spray process. Careful touch up and or powder coating, specially on the valve covers (prone to sustain scratches) provide good repairs.