Iridium Spark Plug Gap For Generator

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I have a Briggs and Stratton 5500W generator with the Briggs 342cc engine. The owner's manual calls for a .030 plug gap for plug. The factory plug is the Champion RC12YC. I purchased an iridium NGK BKR5EIX-11 plug to replace it. Out of the box the gap is .038 for the NGK. Should I reduce the gap to .030 or leave it at the .038? While it currently starts with ~2-4 pulls I'm hoping it will start quicker with the iridium plug. I had spinal cord surgery and living with reduced strength unfortunately. If a simple spark plug change aids in ease of starting I'll be happy. Otherwise I'll be no worse off ;).
 
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Go to .030 as it's a magneto ignition.
You'd do better with the RC12YC or another copper plug. Copper is a better conductor than Iridium.
 
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Don't even aim this low on how to reduce strain on your back. Leave off (or put a hole in) the flywheel cover, so you can insert a deep well socket, to start the engine with an impact driver or wrench instead of by hand-pull. I mean cordless tool of course, since a power outage is a bit incompatible with mains AC powered (or AC mains electric air compressor powered too) tools.

Another option might be to see if the B&S has a compatible battery powered starter, like they'd put on their riding mower engines, though if you have the cordless impact tool and a socket, it's almost as easy and lower cost.

However, yes, use the OE spark gap.
 
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I have a Briggs and Stratton 5500W generator with the Briggs 342cc engine. The owner's manual calls for a .030 plug gap for plug. The factory plug is the Champion RC12YC. I purchased an iridium NGK BKR5EIX-11 plug to replace it. Out of the box the gap is .038 for the NGK. Should I reduce the gap to .030 or leave it at the .038? While it currently starts with ~2-4 pulls I'm hoping it will start quicker with the iridium plug. I had spinal cord surgery and living with reduced strength unfortunately. If a simple spark plug change aids in ease of starting I'll be happy. Otherwise I'll be no worse off ;).
It's not recommended to adjust the gap on Iridium plugs. I've installed at least seven with the factory gap into small engines and have had no issues whatsoever.
 

Whimsey

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OK, a follow up. I put the iridium plug in, gapped at .034, and at the same time I replaced the hard no-flat factory tires/wheels with HF pneumatic tires/wheels. So the generator was angled up while doing the wheel swap. Immediately upon lowering the generator I tried starting it with the new iridium spark plug in it. It took 4-5 pulls to get it going. I was disappointed needless to say. I rolled the generator back into the garage. Today I rolled it out again, it's been sitting level. It started on the first pull. Previously level starts took ~4 pulls, sometimes I got lucky with 2 pulls, rarely though. The following may be my imagination but when the test
20210306_153907.jpg
20210306_154051.jpg
load, 3000 watts kicked on , it didn't seem to bog down/hesitate as much as previously.The factory plug is posted and it doesn't look bad at all for over 100 hours. the gap was still at .030, factory setting. If it continues to start on the first pull I'll be happy, the running smoother and if I get a bit better fuel usage are bonus points.
 
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I have iridium in my harbor freight 4375. Its smooth and starts first pull. Mine clearly runs better with iridium.

I gapped mine at .030.

You have to be careful gapping iridium. Don't use a wheel. I use a feeler gauge. If .028 fits and is loose i roll with that. You dont want to damage the iridium tip or break it. Adjust the gap by bending back from the center.

I crank up my generator every 2 months and run it till its hot.
 

Whimsey

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Dec 22, 2002
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I have iridium in my harbor freight 4375. Its smooth and starts first pull. Mine clearly runs better with iridium.

I gapped mine at .030.

You have to be careful gapping iridium. Don't use a wheel. I use a feeler gauge. If .028 fits and is loose i roll with that. You dont want to damage the iridium tip or break it. Adjust the gap by bending back from the center.

I crank up my generator every 2 months and run it till its hot.
Since the iridium plugs are usually gapped wider than the nickel end plug factory plug I just gently tap the ground electrode on the anvil portion of my bench vise. I went from .038 to .034, close enough to the recommended .030. I do use the wheel feeler gauge but to only check the gap, never to adjust it. I try and run my generator with a 3,000 watt load ~every month for ~45 minutes to an hour. Never had an issue when I really needed to use the generator by doing that. Off season I run my snow blower at the same time for 10 minutes to get it hot. Doing that the snow blower always starts on the first pull when I need it.
 
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I have iridium in my harbor freight 4375. Its smooth and starts first pull. Mine clearly runs better with iridium.

I gapped mine at .030.

You have to be careful gapping iridium. Don't use a wheel. I use a feeler gauge. If .028 fits and is loose i roll with that. You dont want to damage the iridium tip or break it. Adjust the gap by bending back from the center.

I crank up my generator every 2 months and run it till its hot.
you have a 2003 avalanche with just 83K???
 
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Go to .030 as it's a magneto ignition.
You'd do better with the RC12YC or another copper plug. Copper is a better conductor than Iridium.
Almost all “iridium” plugs use a copper core as it would be cost prohibitive to use iridium for the whole thing. Those “copper” plugs use nickel on the center electrode for longevity as copper would quickly wear out. Iridium has less resistance (47.1 nΩ⋅m) than nickel (69.3 nΩ⋅m). The finer point of the iridium plugs are also slightly easier to initiate a spark off of.
 
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