Best Spark Plug to use in WR450F '2011

Electrical Spark Plugs

29 replies to this topic
  • dg400sm

Posted July 18, 2014 - 04:46 PM

#21

i guess yamaha got it wrong then when they wrote the service manual. my drz400 service manual also tells you about which heat range to choose depending on conditions

i think you will find the wr is a high compression engine not a low compression,hence the reason it recommends 95 octane



  • GuyGraham

Posted July 19, 2014 - 12:37 AM

#22

Nothing particularly high comp about the 12.2:1 of the WR

Runs on std pump petrol here in UK - does not need the 98RON of super unleaded.



  • GuyGraham

Posted July 19, 2014 - 12:42 AM

#23


If the motor is not burning all its fuel quickly enough, you put in a hotter plug to assist this

 

 

Have to disagree with you there

 

Plug heat range needs to be hot enough for plug to burn off deposits so it doesn't foul, but not so hot it causes (as you say) detonation

It has nothing to do with burning all the fuel - your jetting is too rich if all the fuel isn't burning.

 

Plug heat range has nothing to do with temp of the metal

It is purely about how hot the plug runs

On NGK, the higher the nmber, the faster the plug loses heat and therefore runs cooler



  • Krannie McKranface

Posted July 19, 2014 - 05:51 AM

#24

Have to disagree with you there

 

Plug heat range needs to be hot enough for plug to burn off deposits so it doesn't foul, but not so hot it causes (as you say) detonation

It has nothing to do with burning all the fuel - your jetting is too rich if all the fuel isn't burning.

 

Plug heat range has nothing to do with temp of the metal

It is purely about how hot the plug runs

On NGK, the higher the nmber, the faster the plug loses heat and therefore runs cooler

 

Well, you can find descriptions on different plug websites for both of our explanations, so I have no clue.



  • stevethe

Posted July 19, 2014 - 09:06 AM

#25

Nothing particularly high comp about the 12.2:1 of the WR
Runs on std pump petrol here in UK - does not need the 98RON of super unleaded.


Not running preimium fuel ?? You running her easy or what.

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  • GuyGraham

Posted July 20, 2014 - 09:13 AM

#26

Not running preimium fuel ?? You running her easy or what.

 

I don't think you really understand about octane mate

Running a higher octane fuel than is needed to prevent pinking/detonation, is actually gonna give you less power. The octane rating is about how resistant the feul is to knock, & nothing about how much power it produces

The higher the octane the slower the petrol burns, so running super unleaded in the WR is gonna result in less power, coz by the time it has all burnt, the piston is on the way down the bore.

 

It has nothing to do with 'running her easy'

The WR does not detonate with 95RON unleaded at full throttle and revs so there is no need for the 98RON of super unleaded.



  • stevethe

Posted July 20, 2014 - 02:11 PM

#27

I don't think you really understand about octane mate

Running a higher octane fuel than is needed to prevent pinking/detonation, is actually gonna give you less power. The octane rating is about how resistant the feul is to knock, & nothing about how much power it produces

The higher the octane the slower the petrol burns, so running super unleaded in the WR is gonna result in less power, coz by the time it has all burnt, the piston is on the way down the bore.

 

It has nothing to do with 'running her easy'

The WR does not detonate with 95RON unleaded at full throttle and revs so there is no need for the 98RON of super unleaded.

 

Well I will definitely be sticking with premium pump fuel 12.2 to 1 is nothing to sniff at. That would be considered premium pump fuel any day of the week. Were in So cal. and these bikes are run hard and hot. 



  • Krannie McKranface

Posted July 20, 2014 - 03:37 PM

#28

Premium fuel in my experience makes the bike run quieter and cooler.

Otherwise, the increase in octane is meaningless, unless you run a 13:5 piston.



  • William1

Posted July 21, 2014 - 11:54 AM

#29

Buy the stock CR8E or CR9E (not enough of a variation to loose sleep over). Replace it once a year. A mistake I have seen is people buy the fine wire plugs and then never touch them. They carbon up like stockers. The steel shell rusts. The ground electrode still wears.



  • vlxjim

Posted July 22, 2014 - 02:58 PM

#30

The use of premium fuel is for both the high comp and also even more so the timing advance. If you have cut the gray wire or you have the new FI WR's with the comp ECU, premium fuel is a must. Most people think that the higher the octane the more explosive the fuel is, this is not true. Higher octane fuel is more refined so that it ignites at a higher temp. This allows more compression and more advance in the timing. Both of which cause the temps in the cylinder to rise to the point of pre ignition. You want to compress the fuel and let the spark plug fire at the set timing point. When running lower octane fuel your compressing the fuel and letting the fuel ignite before the plug fires. This is also how a diesel works, but a diesel is built to work like that.

 

It runs quieter do to it not pinging from pre ignition.


Edited by vlxjim, July 22, 2014 - 05:37 PM.






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