Sparkplug question for mowers

[JTsyo]

Are the Honda spark plugs BPR5ES and BPR6ES interchangeable?

BPR5ES
BPR6ES

One is in my mower now and the other I bought from Home Depot. I noticed that the one in the mower had a flat where the plug is while the other is countersunk.

 

[shabby]

The numbers designate that one is colder and the other hotter, if they're different shapes the letter designation should be different.

 

[Zenmervolt]

In terms of fittiment, the plugs are identical (i.e. the BPR6ES will fit properly in any engine that uses the BPR5ES and vice versa).

BPRxES is an NGK part number (which makes sense, Honda contracts out their "factory" plugs to NGK). The BPR5ES will run hotter than the BPR6ES. Running a BPR6ES in an engine designed for a BPR5ES may cause premature fouling, and running a BPR5ES in an engine designed for a BPR6ES may cause detonation. For more information about decoding NGK plugs, you can follow the link at the end of this post.

In practice, a lawn mower engine is not a hugely sensitive piece of machinery and there are large tolerances built into the design. Either plug should work acceptably.

Decoding NGK plug numbers: http://www.kaila.net/tl125/tl125ngkcode.html

ZV

 

[JTsyo]

Originally posted by: Zenmervolt
In terms of fittiment, the plugs are identical (i.e. the BPR6ES will fit properly in any engine that uses the BPR5ES and vice versa).

BPRxES is an NGK part number (which makes sense, Honda contracts out their "factory" plugs to NGK). The BPR5ES will run hotter than the BPR6ES. Running a BPR6ES in an engine designed for a BPR5ES may cause premature fouling, and running a BPR5ES in an engine designed for a BPR6ES may cause detonation. For more information about decoding NGK plugs, you can follow the link at the end of this post.

In practice, a lawn mower engine is not a hugely sensitive piece of machinery and there are large tolerances built into the design. Either plug should work acceptably.

Decoding NGK plug numbers: http://www.kaila.net/tl125/tl125ngkcode.html

ZV

Alright thanks. Guess I'll open the package instead of returning it.

 

[slag]

yeah, just use them. It wont hurt anything

They are both projector tip resistor plugs and like Zvolt said, will work fine.