Spark Plug?
- Thread starter irefin
- Start date
http://www.google.com/cse?cx=partne...2713j10#gsc.tab=0&gsc.q=spark plug&gsc.page=1
Just type in 'spark plug' in the search feature and you'll have lots to read on the subject.
Tom
Just type in 'spark plug' in the search feature and you'll have lots to read on the subject.
Tom
What motor?
If it's a Skyhawk, any Skyhawk, then a NGK BPR7HIX Iridium plug, it's a difference you can actually feel. If it's a cheaper motor it may be too long so beware and crank by hand to check.
Note the 7 is a heat index number, they range from 5-8, the higher the number the more heat it will dissipate. Here in the desert in summer 7's and 8's are best, in cold places 6's may be be better, they hold heat in better and you'd only want a 5 if you lived in the artic.
If it's a Skyhawk, any Skyhawk, then a NGK BPR7HIX Iridium plug, it's a difference you can actually feel. If it's a cheaper motor it may be too long so beware and crank by hand to check.
Note the 7 is a heat index number, they range from 5-8, the higher the number the more heat it will dissipate. Here in the desert in summer 7's and 8's are best, in cold places 6's may be be better, they hold heat in better and you'd only want a 5 if you lived in the artic.
From my web site:
The way I see it, it is all about how well the plug dissipates heat to the head.
Look at the size difference in the white insulator length where the plug threads are.
The more white you have in contact where the threads are, the more heat is transferred to the cooling fins, and the pink is just providing an air gap to keep heat in.
I would also have to argue that an air cooled motor dissipates much more heat much quicker in a freezing wind opposed to a frigg'n hot one.
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Engine Speed and Load
* If the engine is to be operated at high RPM, under a heavy load, or at high temperatures for long periods a colder heat range may be needed.
* Conversely, if the engine is to be operated at low speeds or at low temperatures for long periods, a hotter heat range might be needed to prevent fouling.
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Ya, I do my homework and test so I know and then share and that particular topic is 2 years old and why I swear by the Iridium plugs, they really do make a difference I can actually feel.
Just pick the number that best suites how you ride and the temp conditions.
Granted it's not as pronounced a power gain as an expansion chamber but for $8 something you can actually feel.
The way I see it, it is all about how well the plug dissipates heat to the head.
Look at the size difference in the white insulator length where the plug threads are.
The more white you have in contact where the threads are, the more heat is transferred to the cooling fins, and the pink is just providing an air gap to keep heat in.
I would also have to argue that an air cooled motor dissipates much more heat much quicker in a freezing wind opposed to a frigg'n hot one.
----
Engine Speed and Load
* If the engine is to be operated at high RPM, under a heavy load, or at high temperatures for long periods a colder heat range may be needed.
* Conversely, if the engine is to be operated at low speeds or at low temperatures for long periods, a hotter heat range might be needed to prevent fouling.
----
Ya, I do my homework and test so I know and then share and that particular topic is 2 years old and why I swear by the Iridium plugs, they really do make a difference I can actually feel.
Just pick the number that best suites how you ride and the temp conditions.
Granted it's not as pronounced a power gain as an expansion chamber but for $8 something you can actually feel.
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In Illinois I'd use a 7 in the summer and a 6 in the winter. That's what I did when I lived in North Dakota. Too cold for me to ride when a 5 would work 
I use a BH7S in my 66cc 2stroke. Why? After reading the plugs, the 7 showed the best ground strap. I think the NGK website has a guide to select proper heat range. The ground strap should show discoloration about halfway to the base ring of the plug. Lower compression heads may need a hotter plug. Plug gap can also effect the heat range. Using a smaller gap may need a colder plug.
I used to use a projected plug, but if I didn't index it right, the extended ground strap would just barely hit the piston. I didn't feel it was worth it to keep the projected plug for this reason, and I didn't notice a performance gain from the projected plug.
Iridium and other such plugs are not going to give a performance benefit. They may last a bit longer, but is that really worth it? I find special more durable plugs most useful in engines where it's difficult to get to a plug, but it's so easy to replace these plugs that I'd rather just pay $1.75 for a standard plug. Electrodes are electrodes, some exotic material doesn't make the engine produce power out of nowhere.
A resistor spark plug can be useful if you have electrical interference. I never had problems with interference, so I use a standard plug. I have tried a resistor plug, and it made no difference for me as far as plug output. I also run things off the white wire. Maybe I have an exceptionally good coil?
These are my opinions. Some people may quietly nod and think I have good advice, some people may stand up on their chairs and throw their monitor out the window at my terrible advice. Either way, it's what I do, and I've had good results. These engines all run a bit differently, so it's worth it to play around with different combos.
I used to use a projected plug, but if I didn't index it right, the extended ground strap would just barely hit the piston. I didn't feel it was worth it to keep the projected plug for this reason, and I didn't notice a performance gain from the projected plug.
Iridium and other such plugs are not going to give a performance benefit. They may last a bit longer, but is that really worth it? I find special more durable plugs most useful in engines where it's difficult to get to a plug, but it's so easy to replace these plugs that I'd rather just pay $1.75 for a standard plug. Electrodes are electrodes, some exotic material doesn't make the engine produce power out of nowhere.
A resistor spark plug can be useful if you have electrical interference. I never had problems with interference, so I use a standard plug. I have tried a resistor plug, and it made no difference for me as far as plug output. I also run things off the white wire. Maybe I have an exceptionally good coil?
These are my opinions. Some people may quietly nod and think I have good advice, some people may stand up on their chairs and throw their monitor out the window at my terrible advice. Either way, it's what I do, and I've had good results. These engines all run a bit differently, so it's worth it to play around with different combos.
