Iridium Spark Plugs

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HandLogger

HandLogger

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As all of our saws use them, I was just getting ready to order some NGK BPMR7As...and then I remembered some positive information I read about iridium type spark plugs.

Does anyone happen to know which iridium plug(s) cross to the BPMR7A?

Other than the price, are there any other cons to running this type of plug in a saw?

Thank you for your time.
 
bwalker
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One report I seen was that copper plugs conduct better than iridium.
They do conduct heat slightly better and have slightly less resistance.
Iridium last longer though, which is why they are used in automotive applications. Really you need iridium or some other metal on the tip and the ground strap to last longer as the steel ground strap erodes away well before the tip. Just an iridium tip is pretty pointless.
For a two stroke the offer no advantage at all other than making your wallet lighter..
 
HansFranz

HansFranz

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I don't think I've ever had to change a saw spark plug. I've tried once or twice when I hoped that was the problem, but it never was.

Seems like if I can get 160k miles (say 3k hours) out of my truck spark plugs, any saw plug ought to outlast the heat death of the Universe.
 
SteveSr

SteveSr

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I don't think I've ever had to change a saw spark plug. I've tried once or twice when I hoped that was the problem, but it never was.

Seems like if I can get 160k miles (say 3k hours) out of my truck spark plugs, any saw plug ought to outlast the heat death of the Universe.
I generally don't change plugs as long as they appear to function. If the tool is tuned properly and used properly spark plugs are self-cleaning.
 
j-jock

j-jock

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From the early 70s, I have been running platinum, and for the last ten years platinum or iridium plugs, in all my vehicles.
Back in the 70s, I had a Husqvarna dirt bike, a 400 cc - 8 speed, that I used to ride competitively, and that thing was brutal on plugs. I solved the problem by installing platinum plugs, and that sold me on using them. (I always carried a spare when riding in the desert, and never needed it).
I noticed, that because of the thinner electrode, that it would continue to fire, when a standard plug would foul.
I have run a lot of high performance vehicles, with and without CD ignition, (390, 428, 396, 427, 454 ci) and these plugs have never let me down. ( I did have one Bosch plug fail, but that was because the resister in the plug failed). For a time span of 50 years, that isn't a bad deal.
 
serdie

serdie

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Iridium plugs are a waste of money in chainsaws and i won't use E3 plugs either.
Iridium plugs are used with a very high voltage coil, not the usual cd or point fired system like on my Husky’s or Macs. They also require a greater gap at that voltage to achieve that spark. I still use champions in my Macs and Ngk in the Husky’s.
 
bwalker
Joined
Jun 3, 2002
Messages
13,867
Location
Montana
From the early 70s, I have been running platinum, and for the last ten years platinum or iridium plugs, in all my vehicles.
Back in the 70s, I had a Husqvarna dirt bike, a 400 cc - 8 speed, that I used to ride competitively, and that thing was brutal on plugs. I solved the problem by installing platinum plugs, and that sold me on using them. (I always carried a spare when riding in the desert, and never needed it).
I noticed, that because of the thinner electrode, that it would continue to fire, when a standard plug would foul.
I have run a lot of high performance vehicles, with and without CD ignition, (390, 428, 396, 427, 454 ci) and these plugs have never let me down. ( I did have one Bosch plug fail, but that was because the resister in the plug failed). For a time span of 50 years, that isn't a bad deal.
Should have solved it by jetting the carb.. poor tuning is what causes plugs to fail..
 
Mad Professor
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Jul 2, 2007
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Iridium plugs are used with a very high voltage coil, not the usual cd or point fired system like on my Husky’s or Macs. They also require a greater gap at that voltage to achieve that spark. I still use champions in my Macs and Ngk in the Husky’s.
Champions are Chi-Com crap
 

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