How often to change spark plug?

[mfibre]

Hi, just did my servicing but didnt change spark plug.. I dont know when need to change it. Is there a thumb of rule for this ?

[prego08220]

By right is every 10000click.. So is like after every 2 servicing.. But by left is u can use until the plug cannot be used.. This was told to me by my mech.. He's riding '05model R1... Hope dis help..

[mfibre]

Originally posted by prego08220@May 14, 2007 08:01 pm

By right is every 10000click.. So is like after every 2 servicing.. But by left is u can use until the plug cannot be used.. This was told to me by my mech.. He's riding '05model R1... Hope dis help..

i see.. i guess i dont have to worry as yet. Because, for my family car, when change spark plug, can feel lots of diff, in terms of acceleration and gear changing.

 

I dont know much bout bikes though.. riding just YBR125..

[prego08220]

Arhh.. Small bike no problem la.. Every 10000km change once.. Can be done at malaysia also.. for big bike than problem.. 4 plug.. More $$ spent..

[mfibre]

Originally posted by prego08220@May 14, 2007 10:07 pm

Arhh.. Small bike no problem la.. Every 10000km change once.. Can be done at malaysia also.. for big bike than problem.. 4 plug.. More $$ spent..

Yeah..4. like cars,.

[Strong Eagle]

Hey, I have to put 6 in mine. You really only need to change the plugs when the electrodes become worn, or their are deposits on the plug you cannot easily get off. Usually two strokes need a plug change more often because of the oil they burn. I can easily get 70,000 klicks out of my plugs.

[mfibre]

Originally posted by Strong Eagle@May 15, 2007 06:44 pm

Hey, I have to put 6 in mine. You really only need to change the plugs when the electrodes become worn, or their are deposits on the plug you cannot easily get off. Usually two strokes need a plug change more often because of the oil they burn. I can easily get 70,000 klicks out of my plugs.

6?

So many? what bike is that..

[nhyone]

Originally posted by mfibre@May 14, 2007 08:07 pm

i see.. i guess i dont have to worry as yet. Because, for my family car, when change spark plug, can feel lots of diff, in terms of acceleration and gear changing.

 

I dont know much bout bikes though.. riding just YBR125..

Just inspect during every oil change. If it still looks normal, then leave it alone. As for what's normal, just google. Many sparkplug analysis sites around.

[mfibre]

Originally posted by nhyone@May 16, 2007 10:32 pm

Just inspect during every oil change. If it still looks normal, then leave it alone. As for what's normal, just google. Many sparkplug analysis sites around.

Alright then...personally, do you feel smoother ride with normal spark plug?

[nhyone]

Originally posted by mfibre@May 17, 2007 12:46 pm

Alright then...personally, do you feel smoother ride with normal spark plug?

I can't help you cos I don't know how it feels like with a bad sparkplug.

[Strong Eagle]

Originally posted by mfibre@May 16, 2007 10:28 am

6?

So many? what bike is that..

Honda Valkyrie - 1522 cc's flat 6

 

http://www.herberts.org/wayne/valk/interstatespec.htm

 

http://www.herbhost.com/miscimg/Valk2engine.jpg

[buttbutt8]

i heard that best is can change with every two oil change

[hit.man]

Yup that's right.... typically change spark plugs every 10k mileage should be okie. But depends on individual and also the type of plugs you use. My NGK Iridium used for about 25k already still okie....

 

i heard that best is can change with every two oil change

[tt6389]

my NGK iridium changed out after 15k last friday. But the plugs conditions still look clean & good. Next time I'll wait for 25k.

[tt6389]

Hey, I have to put 6 in mine. You really only need to change the plugs when the electrodes become worn, or their are deposits on the plug you cannot easily get off. Usually two strokes need a plug change more often because of the oil they burn. I can easily get 70,000 klicks out of my plugs.

 

You using iridium plugs? Sometimes I wonder if all those advertising about iridium plugs are really true - similar to those voltage stabilisers gimmicks. I had thought there was a increase in pickup after changing to iridium; but then again it could be psychological. You have any advice on iridiums?

[Strong Eagle]

You using iridium plugs? Sometimes I wonder if all those advertising about iridium plugs are really true - similar to those voltage stabilisers gimmicks. I had thought there was a increase in pickup after changing to iridium; but then again it could be psychological. You have any advice on iridiums?

 

It has been proven that iridium plugs provide a very slight increase in spark power IF the rest of the ignition system is also set up for it.

 

I can't see using iridium plugs for day to day riding because they are just too expensive for what you get back when you use them. So many other factors come into play... like the quality of your ignition coils and the operation of your ICU.

 

Iridium will last longer. If your bike really eats up plugs then maybe they might make sense to evaluate costs of regular plugs and distance travelled against iridiums.

 

As far as sensing more pickup, I just don't think so. For street driving, once the petrol is lit, it is lit, and any difference would be so small as to be un-noticeable.

 

But, don't worry. My butt dyno says my bike goes faster when I waxs and polish it!

[hit.man]

Agree with SE... anyway I got this from NGK website.... for everyone's reading pleasure...

 

Article taken from here : http://www.ngksparkplugs.com/techinfo/spark_plugs/techtips.asp?nav=31000&country=US

 

A common misconception is that changing spark plugs will result in a large power increase. In most cases, removing even seriously worn out spark plugs will only result in very modest power gains, typically about 1-2% of total engine output. This could be even less for computer-controlled vehicles, primarily because most newer vehicles have more powerful ignition systems and the vehicle's computer can make adjustments so that vehicle operation seems smoother and more seamless.

 

Many people think that simply supplying more spark to the firing tip can and will combust more fuel. What they don't understand is that most newer cars' engines are so efficient that they are already burning all of the available fuel. Simply adding more spark voltage can't burn more fuel because there is no more fuel to burn.

 

When a stock or near-stock engine is given a fresh set of spark plugs, peak efficiency is restored. The power gains that come from this restored state of tune are usually minimal. Any company that tells you that their spark plug will provide significant gains in power in a stock or near-stock engine is making blanket statements that may not be supportable.

[tt6389]

It has been proven that iridium plugs provide a very slight increase in spark power IF the rest of the ignition system is also set up for it.

 

I can't see using iridium plugs for day to day riding because they are just too expensive for what you get back when you use them. So many other factors come into play... like the quality of your ignition coils and the operation of your ICU.

 

Iridium will last longer. If your bike really eats up plugs then maybe they might make sense to evaluate costs of regular plugs and distance travelled against iridiums.

 

As far as sensing more pickup, I just don't think so. For street driving, once the petrol is lit, it is lit, and any difference would be so small as to be un-noticeable.

 

But, don't worry. My butt dyno says my bike goes faster when I waxs and polish it!

 

 

thanks for the advice. After that issue on the voltage stabiliser, you have my total respect for your engineering knowledge. So, I 'll probably revert to normal plugs once my iridium life span expires.

 

Just curious, if a guy has S$300 cash budget to spare, what sort of upgrades/ mods is most definitely effective in power boosting? That is for a S4 bike with a simple low tech carburettor & vtec engine. Could it be a second hand Yoshimura/Micron end can? Will that be a clearly better choice than to invest in some sort of electronic spark optimser or voltage stabiliser thing etc?

 

[hit.man]

Actually, I think its better to save that money for your subsequent servicing, cuz honestly, no matter what we do to our Super 4, it is only that powerful...

$300 is difficult to get a 2nd hand endcan based on the current market trend and even if you managed to get one, an endcan alone wouldn't make much difference to your bike's power... yeah... just my opinion...

 

Just curious, if a guy has S$300 cash budget to spare, what sort of upgrades/ mods is most definitely effective in power boosting? That is for a S4 bike with a simple low tech carburettor & vtec engine. Could it be a second hand Yoshimura/Micron end can? Will that be a clearly better choice than to invest in some sort of electronic spark optimser or voltage stabiliser thing etc?

[Strong Eagle]

thanks for the advice. After that issue on the voltage stabiliser, you have my total respect for your engineering knowledge. So, I 'll probably revert to normal plugs once my iridium life span expires.

 

Just curious, if a guy has S$300 cash budget to spare, what sort of upgrades/ mods is most definitely effective in power boosting? That is for a S4 bike with a simple low tech carburettor & vtec engine. Could it be a second hand Yoshimura/Micron end can? Will that be a clearly better choice than to invest in some sort of electronic spark optimser or voltage stabiliser thing etc?

 

 

You can't do much with $300. I'll hunt down a chart that shows dollars spent for horsepower increase so you can get an idea of the real costs.

 

Leaving out all the smoke and mirrors devices, like voltage stabilizers and iridum plugs, there are a handful of things you can do, all of which cost increasing amounts of money.

 

Note too, that if you do get a power boost it will come at the expense of fuel economy (more power means more fuel consumed) and drivability (you may get a "hot" bike but only through a narrow range of RPM's.

 

Place to start: Freer flowing, properly tuned exhaust pipes and headers. Can add 5 to 15 percent HP boost, depending upon bike. You have to research carefully... most aftermarket pipes lose HP. You may have to rejet for better pipes... and in Singapore you need to worry about legality.

 

Different carbs or EFI mapping - can squeeze more petrol into a cylinder in hopes of better power... at the expense of mileage. But often you get more power in a very limited range, and usually not what normal driving needs require.

 

Port and polish intakes and heads.... nominal increase in power, maybe none, depending upon your bike.

 

Shaved heads... increased compression yields more power... and requires higher octane petrol.

 

Different cams... can definitely boost power, but through a narrow range... you pay with drivability issues... worse low end torque, for example.

 

NOS - Hey, this will really make your bike shoot forward... for a few seconds. Prolonged use of NOS about guarantees piston failures without stronger pistons.

 

Blower - the way to really go if you want more power. Most expensive for $$ to HP. May require stronger pistons. You can easily get 50 percent more HP with a blower... at the expense of engine life and drivability and mileage.

 

The easiest way to get more power is to get more cc's. Big moto, good (like mine). Big moto, high RPM (like liter sport bikes)... plenty HP in the upper RPM spectrum.

[Strong Eagle]

So... here is the link to $$$ per HP gained. This informatin is for the Valkyrie... but I think you get the drift... $78 US per HP gain on average... which is about S$ 130. $300 could get you a 3 HP increase on a machine which produces about 100 HP... don't know about your bike.

 

http://www.timskelton.com/valkyrie/tech/dollars_per_hp.htm

 

Trigger wheel advances timing: Probably not an option with bikes more sophisticated than tha Valk.

 

Dyna 3000: An ICM switchout with different spark curves

[tt6389]

Thanks again for the info. Looks like the best option for low budget people like me is modifying the exhaust for better flow. The $ to horsepower gain ratio is pretty decent.

 

Don't feel good spending a bomb nor making drastic mods such as blower. Might as well upgrade to bigger engine capacity. That blower thing mentioned I supposed is turbo charger right?

[tt6389]

 

Place to start: Freer flowing, properly tuned exhaust pipes and headers. Can add 5 to 15 percent HP boost, depending upon bike. You have to research carefully... most aftermarket pipes lose HP. You may have to rejet for better pipes... and in Singapore you need to worry about legality.

 

Currently my stock exhaust end opening where the smoke comes out has a smaller diameter than the main header's diameter (about 20% smaller). If I change my stock exhaust pipe to a straight through exhaust pipe which is having the same cross sectional area as the main header, then there should be a faster flow of the exhaust gases which might be important for power boost at high rpm when lots of gases are flowing thru. Question here is in addition to this, I need to "rejet" in order to maximise the HP gain. What is "rejet" ? Can rejet be done for carburettor type engines?

[Strong Eagle]

Currently my stock exhaust end opening where the smoke comes out has a smaller diameter than the main header's diameter (about 20% smaller). If I change my stock exhaust pipe to a straight through exhaust pipe which is having the same cross sectional area as the main header, then there should be a faster flow of the exhaust gases which might be important for power boost at high rpm when lots of gases are flowing thru. Question here is in addition to this, I need to "rejet" in order to maximise the HP gain. What is "rejet" ? Can rejet be done for carburettor type engines?

 

A straight pipe such as you are talking about will probably cause the bike to lose power. Every pulse of exhaust from the engine generates a pulse wave that travels down the pipe. When it reaches a restriction, a bend, or the end of the pipe, a reflected wave is sent back up the exhaust pipe.

 

Properly designed, the reflected wave low pressure point reaches the exhaust port at the same time the valve opens and this helps scavenge exhasut gases. Not done properly and the high pressure pulse reaches the valve when it opens, reducing scavening and causing poorer performance.

 

A straight pipe, properly cut to the right length will provide maximum scavenging at exactly one RPM level. Therefore, pipe design usually makes allowances to get the best scavenging across a range of RPM's.

[Strong Eagle]

Thanks again for the info. Looks like the best option for low budget people like me is modifying the exhaust for better flow. The $ to horsepower gain ratio is pretty decent.

 

Don't feel good spending a bomb nor making drastic mods such as blower. Might as well upgrade to bigger engine capacity. That blower thing mentioned I supposed is turbo charger right?

 

Could either be a turbocharger (which is driven by exhaust gases and tends to be impractical for a bike) or a supercharger which is belt or gear driven from the engine. Superchargers give the best throttle response because you don't need to wait for a turbocharger to wind up.