BLACK PLUGS
in 912 / 914 Technical Questions
8 years ago
I have a 2007 912 with 960 hours on it. Last summer I lost full power on take off (4000 rpm max) and did a great deal of trouble shooting and repair to fix the problem. I replaced the throttle cables, cleaned the carbs and replaced the fuel from the mechanical pump to the fuel distribution header, cleaned out the header and balanced the carbs. The problem was fixed and I flew about another 20 hours and the engine ran great.
A couple of days ago I changed the plugs (they had about 60 hours on them) and this is what I got (see picture below). The right engine plugs were black. In the past all the plugs always looked good.
The question is could this be related to the loss of power last summer when only half the engine was running and why black? I thought black meant too rich mixture but if there was restricted fuel flow to one side why would the plug turn black?
I plan to pull the plugs and look at them again in a couple of hours just in case this is a new problem and not as a result of the loss of power problem.
A couple of days ago I changed the plugs (they had about 60 hours on them) and this is what I got (see picture below). The right engine plugs were black. In the past all the plugs always looked good.
The question is could this be related to the loss of power last summer when only half the engine was running and why black? I thought black meant too rich mixture but if there was restricted fuel flow to one side why would the plug turn black?
I plan to pull the plugs and look at them again in a couple of hours just in case this is a new problem and not as a result of the loss of power problem.
plugs1.jpg (You do not have access to download this file.)
plugs2.jpg (You do not have access to download this file.)
plugs1_2016-11-07.jpg (You do not have access to download this file.)
plugs2_2016-11-07.jpg (You do not have access to download this file.)
