Monty Mikho
03-26-2006, 02:14 PM
Here a plug taken from a motor running a .040 and .042 pill (fogger)
Clean plug below..
The arrow on the left shows the heat mark which is near the base of the ground strap (Start of the thread). Anything hotter will make this mark go lower (down onto the threads). Anything colder will move this mark up
(towards the radius of the ground strap).
The arrow on the right shows the fuel ring. Notice it is at the base of the plug. It falls between the inter metal part of the plug and the base of the plug. Anything richer will move up the plug (Like picture # 2). Anything leaner will work towards the metal part of the plug.
Please remember if the fuel ring is in the right spot and you need to add timing. That it will need added fuel as well. Remembering adding timing will give the fuel more time to burn. If the fuel isn't there it will eat a piston. If you remove timing and the fuel is rich remember to remove some fuel.. I think you get the picture.. Let us know how things work out for you. Make you best judgements on which way to move and how much. Try little moves.. Never make two big moves..
http://www.yellowbullet.com/clean1.jpg
This picture is mid rich. It also shows some oil on the plug. Lets discount that at the moment. Notice the fuel ring us 1/3 of the way up the porcelaine? this fuel ring means it is rich. Removing fuel will lower this mark. Adding fuel will raise this mark (Like picture #3)
http://www.yellowbullet.com/mid_rich.jpg
This plug is fuel rich. Notice the fuel ring at the top of the porcelain near the electrode?
http://www.yellowbullet.com/full_rich.jpg
The following plugs show timing heat marks. The marks are identified by the red mark.
The picture below shows the target timing mark for nitrous motors.
http://www.yellowbullet.com/timing_right_on.jpg
The picture below shows not enough heat in the combustion chamber. Adding timing will allow more time for the fuel to burn producing more heat in the chamber. You will need to add around 1.5 degrees of timing if the timing mark falls in this area. Please remember to look at the fuel ring and make adjustments if needed.
http://www.yellowbullet.com/needs_around_1_1_2_degrees_of_timing.jpg
The picture below is too much timing. Removing timing will move this mark off the threads back on to the ground strap. If the timing mark falls in this area. You will need to remove around 1.5 degrees of timing. Don't forget to look at the fuel mark to see if changes are needed
http://www.yellowbullet.com/remove_around_1_1_2_degrees_of_timing.jpg
Please note that lean fuel mixtures will add heat to the combustion chamber as well. Use the standard 1 degree of timing per 25 HP and the jet spread/fuel pressure recommended with your kit. Work your way to a better tune up from there. Personally I like to remove the fuel and add timing (if needed in that direction) in very small increments. Making big moves will make a lot of wasted aluminum...
The plug below is an oiled down plug. Notice the glaze look to the porcelain. The dark spot at the base is the fuel ring. The tan/gray is the oil. Please do not confuse the two. They look totally different.
http://www.yellowbullet.com/cutaway_oil_on_plug.jpg
Play safe, make small moves and take it easy. This stuff will come with time. Use a new set of plugs after reading the first set. Using a used set of plugs will mislead you down the wrong path. Save these plugs till your tune up is done then you can reinstall them in the motor (unless they are wasted of course). Take your time with reading. 5 minutes of time will save you $1000 in broken parts and hours of rebuild time.
Clean plug below..
The arrow on the left shows the heat mark which is near the base of the ground strap (Start of the thread). Anything hotter will make this mark go lower (down onto the threads). Anything colder will move this mark up
(towards the radius of the ground strap).
The arrow on the right shows the fuel ring. Notice it is at the base of the plug. It falls between the inter metal part of the plug and the base of the plug. Anything richer will move up the plug (Like picture # 2). Anything leaner will work towards the metal part of the plug.
Please remember if the fuel ring is in the right spot and you need to add timing. That it will need added fuel as well. Remembering adding timing will give the fuel more time to burn. If the fuel isn't there it will eat a piston. If you remove timing and the fuel is rich remember to remove some fuel.. I think you get the picture.. Let us know how things work out for you. Make you best judgements on which way to move and how much. Try little moves.. Never make two big moves..
http://www.yellowbullet.com/clean1.jpg
This picture is mid rich. It also shows some oil on the plug. Lets discount that at the moment. Notice the fuel ring us 1/3 of the way up the porcelaine? this fuel ring means it is rich. Removing fuel will lower this mark. Adding fuel will raise this mark (Like picture #3)
http://www.yellowbullet.com/mid_rich.jpg
This plug is fuel rich. Notice the fuel ring at the top of the porcelain near the electrode?
http://www.yellowbullet.com/full_rich.jpg
The following plugs show timing heat marks. The marks are identified by the red mark.
The picture below shows the target timing mark for nitrous motors.
http://www.yellowbullet.com/timing_right_on.jpg
The picture below shows not enough heat in the combustion chamber. Adding timing will allow more time for the fuel to burn producing more heat in the chamber. You will need to add around 1.5 degrees of timing if the timing mark falls in this area. Please remember to look at the fuel ring and make adjustments if needed.
http://www.yellowbullet.com/needs_around_1_1_2_degrees_of_timing.jpg
The picture below is too much timing. Removing timing will move this mark off the threads back on to the ground strap. If the timing mark falls in this area. You will need to remove around 1.5 degrees of timing. Don't forget to look at the fuel mark to see if changes are needed
http://www.yellowbullet.com/remove_around_1_1_2_degrees_of_timing.jpg
Please note that lean fuel mixtures will add heat to the combustion chamber as well. Use the standard 1 degree of timing per 25 HP and the jet spread/fuel pressure recommended with your kit. Work your way to a better tune up from there. Personally I like to remove the fuel and add timing (if needed in that direction) in very small increments. Making big moves will make a lot of wasted aluminum...
The plug below is an oiled down plug. Notice the glaze look to the porcelain. The dark spot at the base is the fuel ring. The tan/gray is the oil. Please do not confuse the two. They look totally different.
http://www.yellowbullet.com/cutaway_oil_on_plug.jpg
Play safe, make small moves and take it easy. This stuff will come with time. Use a new set of plugs after reading the first set. Using a used set of plugs will mislead you down the wrong path. Save these plugs till your tune up is done then you can reinstall them in the motor (unless they are wasted of course). Take your time with reading. 5 minutes of time will save you $1000 in broken parts and hours of rebuild time.