f355spider
$50 Site Donor 2025
OP, are you obtaining your plugs from a reputable source? eBay and Amazon are notorious for cheap fakes from China. Make sure you are getting the real NGK product.
Copper vs Iridium spark plugs?
- Thread starter Fabulous50s
- Start date
Its only three spark plugs. Not a place to try to save money.
- Joined
- Mar 19, 2022
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- 712
To answer all the questions. These were installed from the factory. The snowmobile is 13 years old, used very little before I bought it last year. So yes they are genuine NGK.
This is a snowmobile.... I ain't paying $60 for sparkplug. Its not a car, the kids ride it and we go on some rides to other towns. It's SLOW!!! The thing tops out at 55mph.
This is a snowmobile.... I ain't paying $60 for sparkplug. Its not a car, the kids ride it and we go on some rides to other towns. It's SLOW!!! The thing tops out at 55mph.
WHAT?
Just a note. Don't use them in a waste spark ignition. On a "V" engine, one side won't last more than six months.
They're not $60
Rock Auto has the NGK 5477 and the Denso 5377 for $6 each. So about $20 for all three.
The NGK 5477 is the KR8AI
The Denso 5377 is the IX27B
Summit Racing has the Autolite for $6.99 each.
If it's got coil on plug (3 coils- no hi tension leads) you have to run the IR type.
Get a new set, but it sounds like you do have a fueling problem. E10 gasoline and all that sitting, surprised it runs at all. You say it's slow, Must not be running right. That is safer for the kids I suppose, but the engine is being hurt.
I hope you didn't put in an octane booster with MMT - that will kill plugs fast.
Get a new set, but it sounds like you do have a fueling problem. E10 gasoline and all that sitting, surprised it runs at all. You say it's slow, Must not be running right. That is safer for the kids I suppose, but the engine is being hurt.
I hope you didn't put in an octane booster with MMT - that will kill plugs fast.
I interpreted the comment to mean less electrode to quench the flame kernal less/provide better expansion of the initial 'bang' if you will. Supposedly a benefit of fine wires. Excellent point on waste sparks.
I've never had any issues with NGK Iridium plugs in any of my vehicles or powersports equipment and some of them have lived at 120HP per cylinder. I use the 6s, 7s, 8s and 9 series plugs.
But if you want to try a non protruding copper plug then the BR7 series or BR8 would work, if you want the electrode to protrude then add a "P" to the part number (BPR8).
But if you want to try a non protruding copper plug then the BR7 series or BR8 would work, if you want the electrode to protrude then add a "P" to the part number (BPR8).
Kestas
Staff member
The advantage of precious metal tipped plugs over regular plugs is longevity because the tips preclude erosion. Both will give a spark. Regular plugs will have more erosion, but precious metal tipped plugs can have the tips blown off with extended use.
I believe all plugs are copper core.
I believe all plugs are copper core.
So true. With my Briggs and Stratton 5500W conventional generator I finally replaced the factory Champion plug, a standard nickle end plug, with a NGK Iridium plug. With only changing the factory Champion plug I went from taking ~7-9 pulls with the recoil to starting it on 2 pulls with the NGK Iridium plug. This generator has a 342cc engine attached to a large generator head, a lot to turn with a recoil starter. The factory plug looks perfect, almost new, but the iridium plug is a huge improvement with starting.
I've heard claims about a couple of decades ago that there would be no particular benefit to platinum or iridium plugs other than longevity. I used to change the plugs for an inline-4, where it was ridiculously easy to access the plugs. When NGK or ND (now Denso) were $1.50 each, it made sense to just change them every 15-20K miles even though the manufacturer might have recommended 30K miles. However, a lot of manufacturers went to platinum plugs for longevity. The nickel electrodes will still erode, but the platinum or iridium can last. I remember checking factory ND platinum plug at about 70K miles and the gap on each plug was still within specs without ever adjusting the plug, and where adjusting the gap isn't recommended because of the possibility of damaging the tip.
There's also a lot of junk out there. The OEM platinum or iridium plugs are far different than many aftermarket plugs that might have one tip at the ground electrode, but a standard nickel-alloy center electrode. NGK and Denso have the best quality too with a fairly large piece of platinum and not just a fine tip. I remember the worst offender was Bosch platinums with that fine platinum wire in the center electrode. A shop I used to use gave up on them when they tended to erode. I think the OEM style iridium plugs mostly use a platinum puck on the ground electrode, but a think iridium wire for the center electrode. I have heard of some newer designs that use iridium on the ground electrode, where the ground electrode is further away. But this one looks like a platinum puck on the ground.
There might be some classic car plugs that don't have a copper core, but I'm thinking by now there must be modern replacements.
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What? Who said anything about E10? Octane booster? This is a T660 long, wide track. A snowmobile known for being slow....
Yes it's a coil on plug setup.
I put elcheapo Champion $2.50 plugs in in yesterday and it runs and starts fantastic now.
No, quenching is not a problem.
If you want electricity to "jump" from one electrode to another, you want at least one contact to be as small as possible. And, if possible, ground to a point. That's why lightning directors on old farm houses, barns, antenna towers and tall building are ground to a point at the tip.
Yes, understood the main benefit of fine wires is the small and sharp contact area, but there are schools of thought on small electrodes allowing less obstructed flame growth. Quick pull from the web, AAP & NAPA, but is it true????
"As the spark ignites the air/fuel mixture, the colder side electrode tends to “quench” the flame. To combat quenching, some spark plug manufacturers cut a “U” or “V” shaped channel into the “spark receiving” surface of the side electrode. The larger channeled area reduces,,"
".. newer precious metal spark plugs have a center electrode diameter of less than 1.0mm. This smaller diameter center electrode provides more area for flame kernel expansion, further reducing the quenching effect."
Not that I'm a plug nerd or engineer, but back in the dark ages when I was thinking of investing in fine wires for an airplane I was flying, I did get an earful or two on benefits from one of the local hangar rats who actually had some expertise....
Kinda sorta.
The center electrode has little to no effect on spark propagation. The side electrode does. The side electrode presents a wall the spark has to navigate around. This is why spark plug indexing and electrode less spark plugs were popular in the racing world. Racers would also file the top of the side electrode into a "v" to make the spark contact area smaller.
I have not seen a "u" or "v" cut into the side electrode but have seen it done on the center electrode. This is a gimmick from manufacturers to give the center electrode two possible exit paths, ensuring you always have a good electrical path. Really? To me it reduces the wear area of the center electrode. Trust me, the electrical discharge is going to make contact on the least resistive part of the electrodes.
Didn't Denso do a U groove ground electrode back in the day??? Although, IIRC someone, and it may have been the Engineer hangar rat mentioned above, said that the U shaped metal stock solved some manufacturing problem and the marketing folks ran with it. If so, kudos to Marketing!
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NGK V Powers are still available. Gimmick, for sure.
I don’t think you were meaning to say what you’re saying
