new spark plug - Instant Improvement for Generac GP6700E
- Thread starter NavyVet88
- Start date
Mostly apocryphal. WIth the duty cycle it's practically a non-issue for most things. Guys on vintage bike forums argue about 2 vs 3 vs 5 ohm Dyna coils thinking it stresses the ignition and charging system that much but don't account for the duty cycle.
If your ignition coil is teetering on the edge and modding your plug or putting some expensive Iridium in there fixes it then the coil is on its way out and it's time for replacement. The only time maybe I'd say that's acceptable is if it's some coil mounted on the flywheel like OPE and there is no good option except cheap $20 Amazon coils.
NGK is all i use in all of my power equipment. Never had any issues
Autolite iridium extreme starts in both my flathead Tecumseh snowblowers. The have been in them so long I can't remember how long.
My Ariens 8hp blower has burnt through 10 gallons of gas in the last 2 winters on that same plug with zero issues. And that plug will be in there for next winter.
My Ariens 8hp blower has burnt through 10 gallons of gas in the last 2 winters on that same plug with zero issues. And that plug will be in there for next winter.
Most OPE engines use a magneto which does not produce much voltage when pulled over to start, the precious metal plugs require much less voltage to fire due to their thinner electrode. I noticed this years ago with the snowblower, it not only starts easier but with a regular plug if you let it idle it would start bogging down after a short time and give a nice black puff of exhaust when returned to full throttle.
With the precious metal the idle never bogs and no puff of black smoke. Snowblowers tend to run rich because of the conditions they operate in, the fuel consumption dropped dramatically.
My wife could never get the lawnmower going, I had to go out a do it. I put a B&S platinum in it and she can fire it right up. She could not pull it over with enough gusto to make the magneto generate enough energy to fire the plug. Here are some references and some interesting info on electrode design.
https://www.clubplug.ca/NGK-Iridium...9U8O2JRQdT-SZ9WoS7RyKus18hKxebg_slifNWpzXzF4A
https://www.ngk.com/using-the-ngk-cross-reference
https://www.ngk.com/ngk-ground-electrode-designs
With the precious metal the idle never bogs and no puff of black smoke. Snowblowers tend to run rich because of the conditions they operate in, the fuel consumption dropped dramatically.
My wife could never get the lawnmower going, I had to go out a do it. I put a B&S platinum in it and she can fire it right up. She could not pull it over with enough gusto to make the magneto generate enough energy to fire the plug. Here are some references and some interesting info on electrode design.
https://www.clubplug.ca/NGK-Iridium...9U8O2JRQdT-SZ9WoS7RyKus18hKxebg_slifNWpzXzF4A
https://www.ngk.com/using-the-ngk-cross-reference
https://www.ngk.com/ngk-ground-electrode-designs
I found out that B&S sells a platinum plug for the old flat head engines and I used that for my 10hp Tecumseh snow blower. I don't know if it made any difference but when it's -20C out I want every advantage for that thing to start (0w30 in the crankcase).
I believe it was this one:
https://shop.briggsandstratton.com/...um-spark-plug-diy-packaged-version-of-796112s
I believe it was this one:
https://shop.briggsandstratton.com/...um-spark-plug-diy-packaged-version-of-796112s
That is the one in my lawnmower also, it replaces the very common OPE flat head plug J19LM, RCJ8, CJ8 and RJ19LM.
I once could show you an NGK plug from a Honda open-frame generator that was bad. It would start and run great for about 10 seconds then sputter and slow down and finally stall like it was starving for gas. It wasn't though, it was the **** plug shorting out internally. When I finally figured that out (probably by swapping in a Torch being the only other plug at hand), I threw that plug into the woods as far as I could. Don't assume that any part is going to be infailable because of the brand. And always have a spare plug for any one-cylinder engine.
Thanks for the first hand information!
However, all modern plugs (including iridium) have 5K Ohm resistor. Doesn't that add more resistance? Where some old-school copper/nickel plugs don't have any resistor.
There is no real difference the only radio and possible electronic interference. Resistor good is to use.
I've had two separate issues with NGK spark plugs; I've switched to Champion now. They're not like they were back in the day. I had a hard time diagnosing a generator because I assumed the NGK plug was good. I had another issue with one in a Briggs mower. They were from NAPA so I doubt they were counterfeit.
That's very odd. I use about ~100 plugs a year and have switched all to NGK GP. Every Champion I pull has a crooked electrode (disgraceful). NGK is no trouble and always reliable. I've never found a better plug and the difference in build quality is noticeable.
Don't know what else to say.
I just ordered a few ngk’s for several applications. I went direct to their website and they aren’t charging a King’s ransom for legit product. I’ve got several pieces of equipment to outfit with their stuff and plan to properly. Your post reaffirms this was a good call.
NGK's work fine in my current and previous Generac's. My old 5.3 Tahoe didn't like them, rougher idle than the AC spec'ed plugs in it.
NGK's where the go to plugs in all the snowmobiles I've owned. Iridium's lasted for years in 2 stroke motors which are hard on plugs.
NGK's where the go to plugs in all the snowmobiles I've owned. Iridium's lasted for years in 2 stroke motors which are hard on plugs.
My WEN generator came with a Torch and the manual literally said to replace with NGK as part of the pre startup procedure.
I have NGK bpr6eix iridium spark plugs in 3 generators. They start easy.
Nice, which plug does it take? Where did you buy from?
I just did a bit of a deep dive on some NGK in the last two days (thanks forum) and found out that they seem to be changing their number system. I found approx 35 part numbers that can fit a typical BKR5ES (BCPR5ES) application and was able to whittle that down to some useful information.
Most of the iridium plugs have a standard ground electrode (steel) and I think all the ruthenium were dual (platinum ground). To me the best deal is absolutely the G-Power platinum (standard ground) as all the plugs with platinum ground, regardless of center tip, are double or triple the money. I have no issue paying 50% more for platinum but it would make sense that adding another platinum tip (Laser plug) would cost the same increase, not 100% more of a whole single platinum plug (G-Power).
For waste-spark ignition systems, dual-tips are definitely the way to go but the price increase doesn't add up. If you're OK with a 50k mile plug then a single tip is fine and I don't see the value in iridium or ruthenium over platinum.
My Kohler 20KV standby natural gas generator, with 2 plugs, specs a plain Champion copper plug. It's a 2017 model, got some heavy use from outages over the years. Pulled the plugs in 2025, and they looked brand new. Maybe the natural gas fuel has something to do with it, I really don't know. I checked the gap, it was good, and put them back in. Machine exercises 1X a week, and fires right up. Whenever they do need replacing, I'm going back with the same plug in that Kohler engine. As for my gasoline powered OPE, The Champion Platinum plug truly is the best I've used for ease of starting and longevity.
I read before that non-resistor plugs makes better spark, especially in inferior vintage machines with dynamo-magnet vs electronic ignition. That's why most of the old-school plugs don't have a resistor. Is that true?
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