Spark Plugs

[Guest]

Planning on replacing my spark plugs as part of winter maintenance on my 82 650G.

Is there a consensus on the best plugs to use?

Was browsing the selection at my local wallyworld and its tough to tell if there's a difference between the $2 plugs and the $8 plugs. Granted these were for cars but I'm assuming the same range of products for motorcycles.

For my car (120k miles) I'm thinking of trying these Halo design plugs for the alleged improvements in efficiency. I've not yet checked to see if they do them for motorcycles.

Thanks!

[Nessism]

Standard issue NGK or ND plug is 100% adequate. Waste of money to spend more.

[Griffin]

Just buy the standard NGK plugs recommended for your bike for about $2-$3 apiece. Your bike will never know the difference between them and the $8 ones.

[tkent02]

its tough to tell if there's a difference between the $2 plugs and the $8 plugs.

About $6.

X 4
____
$24

[bwringer]

Hey, has anyone mentioned yet that high dollar plugs are a complete and total waste of money on a GS?

I splash out $8 every year for a fresh set of NGK B8-ES (the original recommended OEM) plugs for my GS, and spend my money and time on more worthwhile stuff.

Don't fall for all the spark plug horse puckey out there.

Advance Auto and Napa sell NGK plugs for less than $2 each, by the way. They're about a buck more at cycle shoppes for some reason.

[psyguy]

i just wanted to say that i think the concensus is to use the standard plugs but now that i have read what others had to say i think it's a surplus to say it ?:?

[KRISTI'SGS550]

Add another vote for standard plugs. And NGK is the brand I usually get. I had splitfires in my GS when I bought it, not too happy with those puppies.

[rphillips]

NGK or bust !!!

[jbs80106]

Thanks!

Now I know! Saving money is always good with me!

[focus frenzy]

sad to see so many closed minds.

some premium plugs can give some benefits, you won't find extra 20hp with them but improvements in starting, economy, torque and smoothness can result.

un-shrouding the spark is best, Bosch +4 plugs are proven to give a little edge in power. they expose the spark instead of covering it up.

electricity likes to jump from and to sharp points, just look at lightning rods, nice sharp points.
with NGK iridium plugs the center electrode is very sharp little point, they require less voltage to initiate a spark so you get a spark with more current. this equals a hotter bigger spark and with the stock early GS coils this is a very good thing.

I have run the iridium plugs and the difference when starting was very clear, more often than not just a bump of the starter would fire the engine right off.

with conventional plugs (been made the same for almost a hundred years) it take a higher voltage to initiate the spark so the current is lower and you end up with a weak yellow spark.

conventional plugs start out with a sharp edge to the center electrode but it quickly wears down and the center electrode develops a rounded profile.

[Steve]

some premium plugs can give some benefits, you won't find extra 20hp with them but improvements in starting, economy, torque and smoothness can result.

I have heard a lot about the Iridium plugs on another board, but could never justify the price for them.

As far as my wife's 850 is concerned, starting any easier would mean we would only have to think about pushing the button.
Economy? Good, might get it past 60 mpg yet.
Torque? She doesn't use all she has available now.
Smoothness? Again, not a problem. Not as smooth as a turbine, but still not a problem.

I might try them some time just for S&Gs, but for the time being, cash outlay still has to be kept to a minimum.


.

[psyguy]

sad to see so many closed minds.

some premium plugs can give some benefits

focus frenzy, i don't think anyone here wants to dispute that there are better spark plugs out there today than 100 yrs ago

but it seems that for our old bikes using expensive premium plugs makes no improvements worth the money

[posplayr]

Sounds like it is worth a try

http://www.gdlcycles.com/asp1/modetails.asp?ItemID=TR_38-0190

NGK IX PLUGS Made of Iridium. Represents the ultimate evolution of spark plugs. Ultra fine electrode designed to reduce the voltage requirement and ensure maximum durability. Iridium is a precious metal that is 6 times harder and 8 times stronger than platinum, it has a 1,200(=F) higher melting point than platinum and conducts electricity better. This makes it possible to create the finest wire center electrode ever. Prior till now, platinum had been favored for long life or performance spark plugs due to its high melting point, also the technology did not exist to machine and bond iridium on a spark plug electrode(at least in a cost effective manner). Iridium industrial spark plugs have been around for years, but still sells for over a hundred dollars per plug. Just now is the technology available to effectively use iridium in a spark plug for automotive applications. The strength, hardness and high melting point of iridium allows NGK to manufacture their iridium ultra-fine wire center electrode to 0.7mm.

http://www.ngkspark.com.au/pages/bulletins/T01-7.htm

NGK have recently released their new range of Iridium IX spark plugs in Australia. Iridium is a precious metal that has the advantage of a higher melting point than platinum and is also more durable. These advantages combined with NGK's patented designs have produced a spark plug that offers performance gains previously not available.

http://www.spark-plugs.co.uk/pages/t...park_plugs.htm

Relatively recent advances in fabrication techniques have enabled the use of Iridium - an incredibly hard precious metal, for the construction of spark plug electrodes. Laser technology is used to weld the Iridium tip to spark plugs manufactured by both Denso and NGK. It's worth noting that spark plugs can't increase the potential power that an engine can generate but a more efficient spark will provide more efficient combustion and associated performance and economy benefits. A poor spark from a worn or low grade spark plug will reduce efficiency. An Iridium plug will produce a more efficient spark.

I fell for it, I picked up 8 for my two bikes :-D
http://cgi.ebay.com/ebaymotors/NGK-I...spagenameZWDVW

I will have to postpone my chrome valve stem cap purchase now.

Posplayr

[p_s]

Fancy plugs have been dynoed, and if there are gains, they are vanishingly small, and not statistically significant.
Here is a representative one:

The difference between runs on the same set of plugs is interesting. Don't trust a comparison of only one run.

[posplayr]

Thanks for the data

That is interesting but it is not clear what the test conditions of the motors or even what type of vehicle it was that produced the results. With a modern ignition there may very well be no differences. I have had excellent results (would not go back) adding a Jacobs ignition system to an old 1981 440 Dodge motor home. It added gas milage, power and drivability. On the other hand, I dont think it would do much of anything for my 1997 fuel injected Triton 5.4L Econoline Van.

From a laymans stand point once you have a good enough spark to initiate ignition and good buring, then more doesn't do any better. The issue is do you have a good enough ignition? For a stock and tired old Suck ignition better plugs alone probably help alot on general drivabilty (like cold starts). I know when I looked at the spark on my stock 81 GS750, I thought I had dead coils first time I saw that weak yellow spark when cranking over the engine.

One interesting thing about the data is that the NGK Iridium plugs have the most consistent set of runs. I'm not sure we can infer anything from this as I mentioned before, we dont know what the test conditions are. I guess I might be disappointed, but I am expecting an improved drivability for my stock 750 from a set of NGK Iridiums.

Posplayr