Honda Spree and Elite 50 Forums

is there a difference between BPR4HS and BPR4HSA? i thought maybe i would use the 4 heat range since its cold to try and finish my tune soon as i get my pipe back. and will that affect the performance when i switch back to the BPR6HSA for warm weather in the spring?

odinxxix wrote:is there a difference between BPR4HS and BPR4HSA?

read here for insight into spark plugs
http://www.ngk.com/charglossary.asp?kw=Heat+range

i recommend that you keep the standard 6 regardless of
ambient temperatures.any problems you may encounter with your scoot in the frigid winter wont be associated with the heat range of the spark plug.
and from that point of view it doesn't matter what heat range is in it because the heat range does not come into play until the scooter is ...up to speed
i take it the scoot has no heat at night...?

actually scooter runs fine,dont ride at night now that its cold, i was just thinking of the hotter plug for the cold weather. i have the 6 in now. runs fine. just a thought.

Greetings:

A hotter plug may become necessary if the ambient temperatures are so cold that the engine runs cooler than Honda-san intended. If that happens, carbon doesn't burn off as well and can accumulate around the insulator and foul the plug out more quickly. The flip side of a too-hot plug for the circumstances is that it can get so hot as to become a glow-plug, igniting mixture in the absence of spark. BPR6 should be OK for all but the most extreme cold temperatures.

The only difference between the BPR4HS and BPR4HSA plugs is one of them will have a small washer on the plug,
the other will not. Thats what the A means on it.
I switched to the number 4 plug from the number 6 on my aero when temperatures were hovering around
5 degrees Celcius/ or 40 degress F. I got my scooter to start at -4 with that plug, about 25 degrees F...
Swap if it gets too cool, leave the 6 if air temps arent a big deal.