BME 110 Spark-plug diagnostic
12-27-2006 | 05:45 PM
#26
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From: Mexico City, MEXICO
RE: BME 110 Spark-plug diagnostic
quote]ORIGINAL: RTK
SS- I think he is using a thermo-couple that wraps around the cylinder so to speak with no need to mount it. But you are right, the rear of the cylinder (in relation to air flow) tends to be hotter. Especially if you do not use much baffling as I used too.
[/quote]
You are right I am using the wrap around thermo-couple.
In this regarding before I mounted the sensors I realized about possible unaccuracy since the thermo-couple were located directly in fornt of the air inlets. However that's exactly what I am doing when I meassure the engine temperatures by using my IR hand hed sensor. I point the IR gun, raight in front of the cowl air inlets to read the tempartures.
I compared the Flight Recorder temperatures in "alive mode" against the readings obtained with a Hand Held IR thermometer, they were pretty close each other. Of course the readings were taken, after stoping the engine, so that I could safely use de IR gun.
Again both instruments turned out readings close each other, sometimes they were far away each other, however I know that the IR gun introduces additional errors since reflecting effects, pointing to different areas, etc
That's the reason why I left the wrap around sensors were I initially installed, however I can try to locate them at the back of the cylinder heads. I am pretty sure as you all already guessed the readings are going to be higher.
I think the temperatures are a relative and in some extend they will give us a good idea about how the engine is doing. In this case I am satisfied with the results, however I don't discard experimenting with other locations.
BTW, unfortunately the RPM sensor is not returning any readings, that happened ever since I ungraded the firmware of the flight recorder. This is other topic I will send a message to the Eagletree.
Perhaps out of topic: I have bad news about the LG. It started de-laminating, I might no be able to continue testing this engine next weekend unless I find the way to temprary re-inforce the LG. I ordered a new LG form Graph Tech.
If you ever have successfully repired a CF LG, please reply to me in this forum:
[link=http://www.rcuniverse.com/forum/m_5161521/tm.htm]CF LG repair[/link]
SS- I think he is using a thermo-couple that wraps around the cylinder so to speak with no need to mount it. But you are right, the rear of the cylinder (in relation to air flow) tends to be hotter. Especially if you do not use much baffling as I used too.
[/quote]
You are right I am using the wrap around thermo-couple.
In this regarding before I mounted the sensors I realized about possible unaccuracy since the thermo-couple were located directly in fornt of the air inlets. However that's exactly what I am doing when I meassure the engine temperatures by using my IR hand hed sensor. I point the IR gun, raight in front of the cowl air inlets to read the tempartures.
I compared the Flight Recorder temperatures in "alive mode" against the readings obtained with a Hand Held IR thermometer, they were pretty close each other. Of course the readings were taken, after stoping the engine, so that I could safely use de IR gun.
Again both instruments turned out readings close each other, sometimes they were far away each other, however I know that the IR gun introduces additional errors since reflecting effects, pointing to different areas, etc
That's the reason why I left the wrap around sensors were I initially installed, however I can try to locate them at the back of the cylinder heads. I am pretty sure as you all already guessed the readings are going to be higher.
I think the temperatures are a relative and in some extend they will give us a good idea about how the engine is doing. In this case I am satisfied with the results, however I don't discard experimenting with other locations.
BTW, unfortunately the RPM sensor is not returning any readings, that happened ever since I ungraded the firmware of the flight recorder. This is other topic I will send a message to the Eagletree.
Perhaps out of topic: I have bad news about the LG. It started de-laminating, I might no be able to continue testing this engine next weekend unless I find the way to temprary re-inforce the LG. I ordered a new LG form Graph Tech.
If you ever have successfully repired a CF LG, please reply to me in this forum:
[link=http://www.rcuniverse.com/forum/m_5161521/tm.htm]CF LG repair[/link]
12-27-2006 | 06:17 PM
#27
Senior Member
RE: BME 110 Spark-plug diagnostic
Just a side note for anyone, once a plug is established as rich, that is its dark, when you get the needle set lean does it go ahead and lighten up?
The residue will burn off and show a new colour according to oil and fuel used. Some will show brown colours, whilst others will show shades of grey.
If the plug is heavily fouled, running leaner and the higher temperature that goes with it may cause glazing of the soot before the plug can burn it off. This glaze can conduct current, and prevent proper voltage buildup for the spark, so your engine will start to misfire. A new plug is due then.
12-28-2006 | 12:03 AM
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RE: BME 110 Spark-plug diagnostic
ORIGINAL: kochj
If that is a new motor, perhaps you should try the non-synthetic oils first for mabay a couple of gallons and then go to the synthetics. This will seat the rings quicker and give you more power and more consistent running engine. If you try adjusting the fuel rich and lean both ways and it still hesitates on take off, make sure all of your seals around your carb is good and nothing has loosened up. If not the case, check the inlet nipples that attach to the fuel lines to make sure they havent lossened up as well. If you do all that and it still is hesitating on throttling up, call BME and tell them you may need to send the engine in to them! BETTER SAFE THAN SORRY...... I am not sure were else to take it,,,, I have spent over 10hours straight trying to get an engine to run right and then I found it had a faulty ignition when I sent it in for warranty..... Oh, one other thing ... Try changing the spark plug for new one and then see if it still stumbles.....
Hope I have helped.
If that is a new motor, perhaps you should try the non-synthetic oils first for mabay a couple of gallons and then go to the synthetics. This will seat the rings quicker and give you more power and more consistent running engine. If you try adjusting the fuel rich and lean both ways and it still hesitates on take off, make sure all of your seals around your carb is good and nothing has loosened up. If not the case, check the inlet nipples that attach to the fuel lines to make sure they havent lossened up as well. If you do all that and it still is hesitating on throttling up, call BME and tell them you may need to send the engine in to them! BETTER SAFE THAN SORRY...... I am not sure were else to take it,,,, I have spent over 10hours straight trying to get an engine to run right and then I found it had a faulty ignition when I sent it in for warranty..... Oh, one other thing ... Try changing the spark plug for new one and then see if it still stumbles.....
Hope I have helped.
When I started troubleshooting the engine "stumble at take off" couple of weeks ago, right after the very 1st maiden flight, I opened the carburetor, found a small piece of transparent plastic flake in the diaphragm(?). The screen was found clean. Replaced the fuel filter for a larger diameter (Sullivan). Solder a brass nipple on on the diaphragm and connected a tube to the inside of the fuselage. Inspected the clunk which by the way was too close to the rearmost wall of the fuel tank, this actually prevented the clunk from freely moving inside the tank! Lucky me I did not have a dead stick during the very 1st maiden flight !
RTK
As mentioned earlier make sure the engine is warmed up, especially before changing any needle settings.
Does it ever hesitate/stumble in flight when you go from an extended low throttle setting to high throttle setting?
As mentioned earlier make sure the engine is warmed up, especially before changing any needle settings.
Does it ever hesitate/stumble in flight when you go from an extended low throttle setting to high throttle setting?
Now couple of weeks later, after leaning the needles, the engine runs better in the air. I did my 1st torque rollings and seems transition pretty good in the air.
I have not running the engine in the air for a long periods of time yet to see if that stmble is reporduced.
If I can fix the LG, I would try something this comming weekend, otherwise I will wait for the Graph Tech LG substitute to arrive, perhaps more than one week from now.
