Predator 3500 Spark Plug

[RhondaHonda]

I picked up a Predator 3500 inverter generator at Harbor Freight and the manual said the spark plug is a Torch F7RTC. I picked up the NGK equivalent but when I went to swap it, the stock plug was a LG F6RTC. What is the difference between a 6 and 7 in the part number? Colder plug?

I put in the NGK and it ran fine after comparing the sizes. Any reason I should go get a different plug?

Changed the oil at a half hour, 1.5 hours and 6.5 hours with Super Tech 10W40 semi-syn. I’ll run this out til 30 hours or so.

 

[Chris142]

You can't compare numbers between different manufacturers.

 

[Propflux01]

Keep the NGK. Even if it is wrong, its better than the torch.

 

[RhondaHonda]

You can't compare numbers between different manufacturers.

I get that, but the NGK equivalent to the F7RTC in the manual is a BPR7ES. The NGK equivalent to the F6RTC that was actually installed is a BPR6ES.

 

[Tman220]

The 7 is a slightly cooler plug, run it as you normally would. The only reason hotter and colder plugs exist is to get them and keep them hot enough to burn off any deposits to prevent fouling, but not so hot that they cause pre-ignition or detonation.
The worst thing that can happen with running a step colder plug is fouling which shouldn't be common on an inverter generator which will throttle the engine to keep a consistent load on the engine. Also today's engines are set up so lean for emissions that fouling should be incredibly uncommon.
Personally I would run the heat range 7 NGK which you already purchased in the unlikely event you have to replace it due to fouling replace it with the slightly hotter 6

 

[Convert]

In the e NGK line, up the higher the number the cooler the plug I.E. BP6ES is Hotter than a BP7ES, BP5ES IS HOTTER THAN BP6ES.

A plug with an R in the sequence is a resister plug. I.E. BPR6ES

I use a BP6ES in my Motorcycle and a BPR4ES in my Kawasaki powered Husqvarna tractor

You can find the NGK numbering system on the NGK. com site.

Tom

CONVERT

 

[spasm3]

I have a predator 4375 generator with the 212cc engine, i believe is the same engine as your 3500. I run the NGK BPR6EIX iridium plug. It starts easily and runs great with this plug. I don't think will probably ever need to replace it.

https://www.amazon.com/NGK-BPR6EIX-Iridium-Spark-Plug/dp/B000UK1Y00/ref=sr_1_2?crid=2F14PSX95VABY&keywords=BPR6eix&qid=1673228697&sprefix=bpr6ei%2Caps%2C118&sr=8-2

 

[RhondaHonda]

Thanks for the info everyone. I’ll stick with the NGK I have in there and hang onto the stock one as a backup. Hopefully this thing doesn’t need to be used but I want it to work if the power is out.

 

[Chris142]

Thanks for the info everyone. I’ll stick with the NGK I have in there and hang onto the stock one as a backup. Hopefully this thing doesn’t need to be used but I want it to work if the power is out.

Buy another ngk for a backup.

 

[Astro_Guy]

I picked up a Predator 3500 inverter generator at Harbor Freight and the manual said the spark plug is a Torch F7RTC. I picked up the NGK equivalent but when I went to swap it, the stock plug was a LG F6RTC. What is the difference between a 6 and 7 in the part number? Colder plug?

I put in the NGK and it ran fine after comparing the sizes. Any reason I should go get a different plug?

Changed the oil at a half hour, 1.5 hours and 6.5 hours with Super Tech 10W40 semi-syn. I’ll run this out til 30 hours or so.

Congratulations on your new generator. See https://bobistheoilguy.com/forums/threads/surprise-found-in-hf-predator-3500-generator.317770/ for my experience with the same machine.

 

[wheelman1991]

My snow blower runs the BPR6ES, and so does my wife's Volvo 240. (Strange but true)