Cylinder Head Darkening
10-30-2005, 11:40 PM
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Cylinder Head Darkening
Hey folks,
One of my favorite engines has been underperforming for the past few weeks so I popped it open tonight. The cylinder head is taking on a darkish hue that can't be rubbed off, the underside of of the glow head is showing similar discoloration and the coil is slightly grey. Can't recall if this means that I'm running it too lean or too rich. Thoughts?
eroc
One of my favorite engines has been underperforming for the past few weeks so I popped it open tonight. The cylinder head is taking on a darkish hue that can't be rubbed off, the underside of of the glow head is showing similar discoloration and the coil is slightly grey. Can't recall if this means that I'm running it too lean or too rich. Thoughts?
eroc
10-31-2005, 05:50 AM
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RE: Cylinder Head Darkening
You are definitely running quite rich and the darkness is the castor , or what ever kind of oil , burned to the top of the cylinder head. When my OS .40 LA had the same crap on it I cleaned it off with soapy water and a nylon scrubby pad. Then I polished the head with a dremel and the polishing wheel. It came out very nice.
10-31-2005, 05:47 PM
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RE: Cylinder Head Darkening
ORIGINAL: eroc144
Hey folks,
One of my favorite engines has been underperforming for the past few weeks so I popped it open tonight. The cylinder head is taking on a darkish hue that can't be rubbed off, the underside of of the glow head is showing similar discoloration and the coil is slightly grey. Can't recall if this means that I'm running it too lean or too rich. Thoughts?
eroc
Hey folks,
One of my favorite engines has been underperforming for the past few weeks so I popped it open tonight. The cylinder head is taking on a darkish hue that can't be rubbed off, the underside of of the glow head is showing similar discoloration and the coil is slightly grey. Can't recall if this means that I'm running it too lean or too rich. Thoughts?
eroc
jess
10-31-2005, 09:54 PM
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RE: Cylinder Head Darkening
Could mean any one (or none) of several things. It would help to know what engine we are examaining.
11-01-2005, 10:21 AM
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RE: Cylinder Head Darkening
The Norvel is neither ABC or ABN. It has a ceramic liner.
I wouldn't worry about any discoloration of the head, but if the coils of the plug are discolored, I would certainly replace the plug. I would stay with the Norvel plug rather than a conversion head and conventional plug.
If the engine has run well for a year I would think your fuel was fine, and that you had not been running overly rich or lean.
I can understand the Norvel .074 being one of your favorites. I have a couple of them. Great little engines!
jess
I wouldn't worry about any discoloration of the head, but if the coils of the plug are discolored, I would certainly replace the plug. I would stay with the Norvel plug rather than a conversion head and conventional plug.
If the engine has run well for a year I would think your fuel was fine, and that you had not been running overly rich or lean.
I can understand the Norvel .074 being one of your favorites. I have a couple of them. Great little engines!
jess
