NGK BKR5E vs BPR5ES

[SonofaBoomer]

I have a Kohler Timecutter that typically runs a pair of RC12YCs. I had a Rotary maintenance pack that came with a pair of NGK BKR5Es which are almost a direct replacement that I have been using. Can I use NGK BPR5ES (I have a bunch for the Honda GCV160) which are pretty similar beside the 'P' projected insulator type which is quite a bit larger sticking out of the engine. Heat rating are both '5' (Medium) and thread reach 'E' is .75, 3/4"... Thoughts?

Seat: Flat​	Seat: Flat​
Thread Size: 14mm​	Thread Size: 14mm​
Heat Range: 5​	Heat Range: 5​
Resistor Type: Yes​	Resistor Type: Yes​
Hex Size (in): 5/8 Inch​	Hex Size (in): 13/16 Inch​
Washer Included: Yes​	Washer Included: Yes​
Preset Gap (in): 0.036 Inch​	Preset Gap (in): 0.036 Inch​
Thread Reach (in): 0.750 Inch​	Thread Reach (in): 0.750 Inch​
Ground Configuration: Standard​	Ground Configuration: Standard​
Ground Electrode Core Material: Nickel​	Ground Electrode Core Material: Nickel​
Number Of Ground Electrodes: 1​	Number Of Ground Electrodes: 1​
Center Electrode Core Material: Copper​	Center Electrode Core Material: Copper​
Center Electrode Tip Material: Nickel​	Center Electrode Tip Material: Nickel​
Ground Electrode Tip Design: Standard​	Ground Electrode Tip Design: Standard​
Approximate Resistor Value (Ohm): 5000 Ohm​	Approximate Resistor Value (Ohm): 5000 Ohm​
Insulator Height (mm): 50.5mm​	Insulator Height (mm): 55mm​
Electrical Terminal Type: Non-Removable Nut​	Electrical Terminal Type: Removable Nut​
Center Electrode Design: Standard​	Center Electrode Design: Standard​
Service Number: BKR5E​	Service Number: BPR5ES​

 

[FowVay]

This is an application issue. The spark plugs are the same with the exception that one (BKR5E) is physically shorter and uses a smaller wrench to install/remove. The BPR5ES provides the same performance but will likely be used in applications that are not access restricted. The insulator height listed in your published data shows that the BKR5E is sized to ISO standards while the BPR5ES is sized to JIS standards. Otherwise, the plugs are the same.

 

[ARCOgraphite]

That is actually a very hot plug in the automotive world, if this is a 4-stroke application, I would prefer the k20 pru-11 denso hot U ground. A vastly superior Ni + Cu core plug vs a V power. Well at least they used to be in the 90's, lol.

I will say O.E. style blue script NGK are better than USA V-power.
I don't like projected tip plugs in A/C ODPE. But if that's what Kohler installs so be it.

 

[SonofaBoomer]

Some more detail:

The Kohler KT725 manual states this:

Engine is equipped with following spark plugs:
Gap - 0.76 mm (0.030 in.)
Thread Size - 14 mm
Reach - 19.1 mm (3/4 in.)
Hex Size - 15.9 mm (5/8 in.)

The Timecutter manual calls for Champion XC12YCs, which were expensive and hard to source back when I needed them last time so I opted for the Champion RC12YCs which were cheaper and easier to find, basically the same. Last maintenance I did, I used a Rotary maintenance kit for the Kohler engine which came with NGK BKR5Es. I assume they all are pretty comparable. I guess as long as the plug meets the above specs it should be fine. I was always partial to NGKs.

 

[ARCOgraphite]

Some more detail:

The Kohler KT725 manual states this:

Engine is equipped with following spark plugs:
Gap - 0.76 mm (0.030 in.)
Thread Size - 14 mm
Reach - 19.1 mm (3/4 in.)
Hex Size - 15.9 mm (5/8 in.)

The Timecutter manual calls for Champion XC12YCs, which were expensive and hard to source back when I needed them last time so I opted for the Champion RC12YCs which were cheaper and easier to find, basically the same. Last maintenance I did, I used a Rotary maintenance kit for the Kohler engine which came with NGK BKR5Es. I assume they all are pretty comparable. I guess as long as the plug meets the above specs it should be fine. I was always partial to NGKs.

How do they read when you pull them? Shouldn't
to need to change them too often. Should make 500 hours easy which I guestimate might be a year commercially.

Doing automobile tunups in the 90's Anytime I pulled a 5 heat range it was too hot, roasted white tips and glazed shell and that on WC engine. Likely the ODPE mower engine runs richer and not at stoich under load so would read better. Happy mowing.

 

[SonofaBoomer]

How do they read when you pull them? Shouldn't
to need to change them too often. Should make 500 hours easy which I guestimate might be a year commercially.

Doing automobile tunups in the 90's Anytime I pulled a 5 heat range it was too hot, roasted white tips and glazed shell and that on WC engine. Likely the ODPE mower engine runs richer and not at stoich under load so would read better. Happy mowing.

They had some carbon on them, one cylinder was worse than the other. Maybe 5's are too cool and they aren't burning the carbon off? Anyways I was able to pick up a 4 pack of the BKR5Es for cheap so I just used those again.