SparkPlug Heat Range

[GuzziYang]

Hi Guys,

 

I know that stock V11 Sport use NGK BPR6ES plugs and I got a bunch of BPR5EVX which is Platinum but the heat range is different. NGK sourch say the higher the number the cooler the plug while other says the reverse. I tend to trust the factory specs but just want to confirm with you guys. If I go with factory heat range then BPR5 is one range hotter then BPR6 and it'll run hotter but is there any concern I should worry about? Never felt my bike was overheating in any kind of weather. My bike is pretty stock 02 V11 LeMans with K&N filter in stock airbox and 2-1 mid-pipe, free flowing exhaust, stock ECU and I'm in Southern California weather.

 

I got like 3 box of BPR5 plugs and like to use it up if it makes minimal difference to bikes running.

[luhbo]

I actually have the Iridium ones built in, they also have the '5' as heat range. Although I see no remarkable difference in engine behaviour I see that those 5ers are too cold for European use. The islolator always looks crusty and tends to get sooty. Never experienced this with the BPR6 cheapos.

Hubert

[moscowphil]

BPR5 is a hotter plug than BPR6 - i.e. the tip of the plug will get hotter if you use BPR5. As it's only 1 grade hotter it might be OK but then again it might not - a hotter plug can cause pre-ignition, which can seriously damage your engine, so personally I wouldn't chance it. For a definitive explanation have a look at http://www.ngksparkplugs.com/tech_support/spark_plugs/p2.asp?mode=nml

[luhbo]

... For a definitive explanation have a look at http://www.ngksparkplugs.com/tech_support/spark_plugs/p2.asp?mode=nml

 

Thanks for that. Could it be that crusty particles are caused by too hot plugs? Why not. I think I will go back to the standard BPR6ES and look for the difference.

Have you tried the plug finder on their page? For the 850LM engine they recommend a BPR7, for the 1100 Breva a BPR8 even. Funny.

 

Hubert

[stormsedge]

I'd suspect detonation (too hot) with particles on the plug. http://www.ngksparkplugs.com/tech_support/spark_plugs/faqs/faqread.asp I usually fall back to the photos to try and decide what is going on.

 

k

[luhbo]

Maybe I just expect too much.

 

 

I wouldn't have seen this as normal, to be honest. This picture requires an engine run well on the lean side I'd say.

 

Hubert

[macguzzi]

bpr6 are very cheap from motor factors dont go to a motorcycle shop

[GuzziYang]

Thanks all for the feedbacks. I did more search and find out that one heat range up is about 7-850 degree hotter plug. I took out the original BPR6 plug and its burning just about right with no oil deposits and touch of white residue on the electrode. I guess I could try the BPR5EVX for few miles and see how the plug is running before deciding. In colder climate a hotter plug might be more suitable and give you more complete burn? The new trend is the Irridum plugs, what benefit compare to Platinum? If we're to change plugs every 6k miles, platinum is already overkill I would think.

[motoguzznix]

Thanks all for the feedbacks. I did more search and find out that one heat range up is about 7-850 degree hotter plug. I took out the original BPR6 plug and its burning just about right with no oil deposits and touch of white residue on the electrode. I guess I could try the BPR5EVX for few miles and see how the plug is running before deciding. In colder climate a hotter plug might be more suitable and give you more complete burn? The new trend is the Irridum plugs, what benefit compare to Platinum? If we're to change plugs every 6k miles, platinum is already overkill I would think.

I wouldn't bother with a hotter plug.

With an open exhaust your engine will run leaner than stock - a hotter plug is not the thing that your engine really wants in that case.

[Skeeve]

The new trend is the Irridum plugs, what benefit compare to Platinum? If we're to change plugs every 6k miles, platinum is already overkill I would think.

 

Advantage of the iridium vs. platinum is even harder more heat resistant electrode, so you can go with an even finer electrode with the same lifespan [or the same size w/ longer lifespan.] The smaller the electrode the easier time of it the spark has in getting started, and less likely to foul since the spark can burn thru any coatings easier.

 

Typically, platinum & iridium plugs have extended change intervals; when plats first hit the market it was 30k vs every 10k for copper plugs, and it's only gone up from there. Some new cars come equipped with iridiums and there is no spark plug change interval: they're done w/ the engine-out belt change at 60k miles [when the Japanese just replace the whole motor, hence the cheap remanned motor prices on late model J-brand cars here in the States! ]