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**sunilg** · 07-12-2012, 01:19 PM

DIY approved.

If you could shed some light on the difference between the normal spark plug and the surface discharge plug, then it would truly complete your article.

**Hackdrag** · 07-12-2012, 04:54 PM

Initial Starting?

Does this effect staring of the bike.

My bike only got one spark plug.

**princesirohi** · 07-12-2012, 05:49 PM

Originally posted by sunilg View Post

DIY approved.

If you could shed some light on the difference between the normal spark plug and the surface discharge plug, then it would truly complete your article.

surface discharge plugs do not foul easily.

**Omid Adab** · 07-12-2012, 07:03 PM

Originally posted by sunilg View Post

DIY approved.

If you could shed some light on the difference between the normal spark plug and the surface discharge plug, then it would truly complete your article.

basically electrode spark plugs are the spark plugs where the spark comes between the electrodes.
A surface sparks plug is basically a ring around the central electrode., its basically like 2 concentric rings.the name is given becoz of the way the spark moves b/w surfaces.
the advantage of the surface sparks plug being no fouling and constant spark for longer time.
logically speaking that normal spark plugs get deposits after some time that reduce the intensity of the plugs.. where as in case of the surface spark plug the central electrode being inscribed in the ring can transfer spark from anywhere.

two biggest applications are racing, and marine applications. Marine since fishing boats alternate so much between high power sprints and very low speed running constantly which tends to quickly foul regular plugs, and for racing because of their intense and very consistent spark, and the fact that they erode at a much much slower rate than regular plugs.

i hope it uncovers the cloud of mystry

**Omid Adab** · 07-12-2012, 07:14 PM

Originally posted by V!RU$ View Post

This thread is about converting your simple stock spark plugs into surface discharge spark plugs.

For this you need to
*break the ground electrode from the spark plug.
*Chisel out any rough edges and try to bring the edges to the same level .
*do a few test runs with spark plug outside before installing it.

Precautions
Do not tamper with the center electrode and insulation as they may break and fall inside the cylinder.
Also i recommend this procedure for twin spark bikes as in case if there is any problem with the spark plug the engine would keep running on at least one spark plug.

Do understand the risks involved and always carry a spare spark plug.

Guys feel free to post comments and possible improvements.

actually need to know your feedback as you have performed the exercise so do you feel any difference in the bike or so??

**ashwinprakas** · 07-12-2012, 08:04 PM

Wont there be a drop in performance? Cause once when I gaped my stock NGK, the bike started skipping beats, even though it worked effortlessly outside the engine.

**V!RU$** · 07-13-2012, 02:04 AM

Originally posted by sunilg View Post

DIY approved.

If you could shed some light on the difference between the normal spark plug and the surface discharge plug, then it would truly complete your article.

thank you for the approval sir.
i've modified the thread according to the format given in the forum.

**Omid Adab** · 07-13-2012, 11:32 AM

Originally posted by V!RU$ View Post

Hello riders i own a pulsar 150 UG4.5(14000 K.M.S. done)
I had a few old spark plugs lying around so i decided to experiment with those plugs.
This thread is about converting your simple stock spark plugs into surface discharge spark plugs.

As we know in a conventional spark plug, it's performance is judged by the length and intensity of spark produced.
If we increase the gap too much the sparking may be weak and may result in misfire.
Also if we gap it too less then the effectiveness of the spark is reduced.

I was surfing the internet and i came across Surface discharge spark plugs from Bosch
and reading about the performance benefits and reduction in arc shielding i decided to try and make these conventional spark plugs as close as possible to surface discharge type.

Generally the spark formation is not properly utilized in an engine due to the ground electrode shielding the arc with respect to the valves hence the flame which originates is not as desired for perfect combustion.
One alternative may be proper indexing of spark plugs which needs additional washers to be placed before the spark plug so that the gap points at the valves.
Or we can use the following method to achieve the best possible spark from our stock spark plugs.

For this you need to
*Break the ground electrode from the spark plug using a plier.
*carefully hold the ground electrode by the plier and pull it away from the center electrode.
*After some repetitions the ground electrode will break away.

*After removal of the ground electrode connect the spark plug to the holder but donot install it in the engine.Kick start the engine(or self start) and notice how the spark jumps from the center electrode to the spark plug body.(Refer to the images attached)

*Now smoothen the edges where the electrode was broken.
*Sand paper or a filing tool can be used.
*The idea is to bring the surface of the ring to the same level at all places so that the spark may alternate throughout the surface.

Precautions
*Do not tamper with the center electrode and insulation as they may break and fall inside the cylinder.
*Also i recommend this procedure for twin spark bikes as in case if there is any problem with the spark plug the engine would keep running on at least one spark plug.

*also bikes with older ignition coils are less likely to be able to provide sufficient voltage for the increased gap.
*Do understand the risks involved and always carry a spare spark plug.

Improvements
# The idling has improved to a great extent and the rpm's are stable at idling.
# The bike starts with a single crank(no need to hold the starter for long or giving throttle) and there is no black smoke or any signs or misfire at any speed.

I am not responsible for any damage to person or vehicle by this procedure(Standard Policy :P)

Guys feel free to post comments and possible improvements.

nice to see this DIY... but still the wanted to knoe one thing that is, even if you cut the grount electrode the spark will still stii work in the 2 electrodes and carbon deposits will be there???
like in your case there are 2 ground electrodes.. even if you cut the electrodes away the sprak will be formed at the 2 points only as per the design of the spark plug..
and as per the design of the surface sparkplugs the whole outer electrode cac conduct spark making it consistant for longer periods...(i.e works well even if carbon deposited are there)...
But then a good job man +1 for that... atlest we can get the surface discharge spark plug for a cheaper price

**B7ACKTHORN** · 07-13-2012, 02:48 PM

Okay now I have two questions. Why did you cut the ground electrodes, that's one and why can't you leave it at as it side by side?

Because either way the spark is only going to be on the side walls, maybe offering slight performance increase. Reliability on this on our four and two strokes will be big question

All in, crisp detail and pics.

Cheers!
VJ

**sooraj_vs** · 07-13-2012, 03:10 PM

I just tried this out.

> Idle RPM constant (cold and hot)
> Change in exhaust note
> Accln. - slightly better

**Omid Adab** · 07-14-2012, 09:01 PM

Originally posted by ashwinprakas View Post

Wont there be a drop in performance? Cause once when I gaped my stock NGK, the bike started skipping beats, even though it worked effortlessly outside the engine.

see the stock electrodes hav the option of moving the electrodes but base of the electrodes are intact... if you look at the pic posted in my earlier posts the the base wont move and thus the base is at a constant gap...

**Honda_CBF** · 07-15-2012, 12:19 AM

Any difference in performance, acceleration, mileage, throttle response etc?
And how do we read AFR with these types of plugs? I mean without any ground electrode?
Btw, will try this mod after some time in my 'single' plug engine, I guess it will help to get more accurate results. Just my thought.

**V!RU$** · 07-15-2012, 02:51 AM

Originally posted by Omid Adab View Post

actually need to know your feedback as you have performed the exercise so do you feel any difference in the bike or so??

@omid thanx bro for the precious information

well as i mentioned in the thread i felt stable idling and better and crisp throttle response.

one of the best things is that the bike starts with the touch of the starter and also it doesn't stall by suddenly giving throttle while idling.
also i was able to keep the idling as low as 500 rpm !!!(between 1000 and zero mark on the tachometer).

so far I've done around 200+K.M.S on this setup and i have not experienced a single problem(like misfire or smoke).
also i will be doing a mileage test today as i am keen to know that whether there are any much improvements, previously i was getting mileage figures of around 52-55 in city/highway.

**V!RU$** · 07-15-2012, 02:57 AM

Originally posted by Omid Adab View Post

nice to see this DIY... but still the wanted to knoe one thing that is, even if you cut the grount electrode the spark will still stii work in the 2 electrodes and carbon deposits will be there???
like in your case there are 2 ground electrodes.. even if you cut the electrodes away the sprak will be formed at the 2 points only as per the design of the spark plug..
and as per the design of the surface sparkplugs the whole outer electrode cac conduct spark making it consistant for longer periods...(i.e works well even if carbon deposited are there)...
But then a good job man +1 for that... atlest we can get the surface discharge spark plug for a cheaper price

thanks for the support man

as i mentioned in the thread i smoothened the entire ring area so that the spark was now able to form randomly throughout the surface and as shown in the attached photos you can see that spark formation is random as i smoothened out the surface.

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D.I.Y Surface Discharge Spark Plug

D.I.Y Surface Discharge Spark Plug

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