I am about to replace the spark plugs in my Generac 16 kW generator. I have the gap and torque specifications but the owners manual doesn't mention if I should use anti-seize compound on the threads. Any suggestions ?
Replacing Spark Plugs In Generac, Need Anti-Seize ?
- Thread starter DwightFrye
- Start date
If it's NGK, don't use anti-seize 
The slightest amount. Don't overtorque the plug. Its easy with anti-seize , to overtighten. I do mine by hand, no torque wrench used.
I've been using specific ceramic grease for the job for the last 10 years or so. Never any issues. Always a small dab of the ceramic grease and torqued to spec.
I used anti-seize on my plugs in my '13 10k Generac. No issues. NGK Iridium plugs also.
I always use it, don't get tighten happy on install.
I always use it, don't get tighten happy on install.
Not required. I don't recommend it. Unless you are running Autolites on an I/O marine application
Why are you doing plugs? How many hours on the meter? They are usually good for a decade.
Rule: Don't mess with Iggy unless there is a good reason.
Why are you doing plugs? How many hours on the meter? They are usually good for a decade.
Rule: Don't mess with Iggy unless there is a good reason.
If you put a lubricant on the threads, reduce the torque when tightening the plug
Newer plugs, particularly NGK, have chromium? threads that do not require anti-sieze compound. In fact, NGK strongly advises against using anti-sieze.
The chromium threads not only reduce corrosion so the spark plug will be easier to remove in the future, but also reduce friction when installing the plug. Thus, NGK states if you feel you must use anti-sieze, it is very important to reduce the torque by 20% from the specification, so as to not over-torque. The combination of the chromium threads and anti-sieze reduces the friction too much and will result in over-torqueing, if the standard torque specification is used.
So unless you are one that is prone to severely neglect spark plug change intervals, I would strongly recommend against using anti-sieze on any spark plug that has chromium threads.
The chromium threads not only reduce corrosion so the spark plug will be easier to remove in the future, but also reduce friction when installing the plug. Thus, NGK states if you feel you must use anti-sieze, it is very important to reduce the torque by 20% from the specification, so as to not over-torque. The combination of the chromium threads and anti-sieze reduces the friction too much and will result in over-torqueing, if the standard torque specification is used.
So unless you are one that is prone to severely neglect spark plug change intervals, I would strongly recommend against using anti-sieze on any spark plug that has chromium threads.
^ Nickel plating if the plug threads are silver, no anti-seize needed and need to reduce torque if you use it. Then there's golden zinc chromate plating which beats nothing but long term, will also oxidize so only skip the anti-seize if changed on a regular basis (every "few" years). If the finish is instead black oxide, found on cheaper plugs, use anti-seize but you still have to reduce torque if the manufacturer did not spec torque using it.
I bought a set of Champion RC12YC plugs at my local NAPA store. The threads look silver or chrome. There are no instructions on the packaging that mention anti-seize compound but it sounds like I won't need it.
I do have a good quality digital torque wrench to torque the plugs.
The Service Schedule calls for "clean, check gap, replace spark plugs" every 4 years or 400 hours of operation. I will have been in this house for three years in September. The house & generator is only four years old and I assume the generator was never serviced. I changed the oil & filter and cleaned the air filter about a year and a half ago. I can look at the run time meter on the generator and I'm sure it is nowhere near 400 hours yet but it is approaching the four year mark. It only fires up when the power goes out and the longest it has ever run was close to 24 hours, usually it is more like 6-8 hours at a time.
But I never regret spending a very nominal amount of money on preventive maintenance so I might as well change the plugs prior to this winter.
I do have a good quality digital torque wrench to torque the plugs.
The Service Schedule calls for "clean, check gap, replace spark plugs" every 4 years or 400 hours of operation. I will have been in this house for three years in September. The house & generator is only four years old and I assume the generator was never serviced. I changed the oil & filter and cleaned the air filter about a year and a half ago. I can look at the run time meter on the generator and I'm sure it is nowhere near 400 hours yet but it is approaching the four year mark. It only fires up when the power goes out and the longest it has ever run was close to 24 hours, usually it is more like 6-8 hours at a time.
But I never regret spending a very nominal amount of money on preventive maintenance so I might as well change the plugs prior to this winter.
Spark plugs don't time out. If they are low hours, just pull them out and visually inspect and adjust the gap if needed and replace.
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I would use it. Just because it’s my habit and I was taught to do it on any spark plug in anything. Not very much just a little bit. I use it on all my car plugs, mower plugs, weed eater plug, etc.
I worked for Generac for 10 years and spent some of that time on the engine line, building the engines. We never used anti-seize at the factory, although it probably wouldnt be a bad idea.
Manufacturers often skip steps like this because of cost. Most owners will never know the difference. If warranty or complaints pop up the company will do a cost to benefit analysis and decide if that analysis warrants a change in the process or not.
Just my $0.02
Not to mention time. When you have an engine rolling off the line once every 3 seconds, taking 5 or 10 seconds to put anti seize on a couple spark plugs is time that you dont have.
I know that I personally never put anti seize on any small engine that I replaced plugs in once a year and never had issues with it, so who knows?
I have changed tons of plugs in OPE, outboards, cars, antique tractors, etc. I've never used anti-seize and never had a problem when removing them down the road once they have been tightened correctly. I have worked on machines where someone made a mess with way too much anti-seize though.
