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Steve2018

Resistor spark plug or non resistor?

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The manual lists both but says to use the resistor type due to some states having different laws (guessing this is just aimed at the US market) 

 

Would there be any difference in fitting the resistor type over the non resistor as that seems more readily available in the stores 

 

Currently the previous owner had a NGK BPMR6A fitted but the manual says to use a Champion J19LM or a NGK B2LM

 

Its for a Lawnflite 504 ride on with a 8hp briggs and stratton engine

 

Thanks

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2 hours ago, Steve2018 said:

The manual lists both but says to use the resistor type due to some states having different laws (guessing this is just aimed at the US market) 

 

Would there be any difference in fitting the resistor type over the non resistor as that seems more readily available in the stores 

 

Currently the previous owner had a NGK BPMR6A fitted but the manual says to use a Champion J19LM or a NGK B2LM

 

Its for a Lawnflite 504 ride on with a 8hp briggs and stratton engine

 

Thanks

Get the nam, resistor ones are the ones with th ‘r’ in the name, they probably help somehow. I’d say stay away from champion, not taht goodin my experience 

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Spark Plugs with resistors are for reducing or eliminating 'ignition noise' and removing 'Peaks' in current which can have a detrimental affect on running. Should be used where specified.

For example, using Non- resistor Plugs can cause erratic Idle, misfires at higher rpm, overrun (pre-ignition), abnormal combustion and power drop at certain speeds.

It all depends on the application etc. 

Ignition noise affects electronics in the vicinity of the engine i.e transistorised  electronic ignition, phones and other equipment.

Make of Plug is personal choice and personally, I use both NGK and Champion and never (50 years) had any fail, but replace when felt necessary.   

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Posted (edited)

Thanks all I went with the Resistor  type NGK resistor gapped to 0.76mm as it was the easiest one to get hold of

 

Just need to stick my new filter on (the one on now is falling to bits)  new breather tube on (a mouse chewed through the one on the engine) and new oil breather gasket 

Edited by Steve2018

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Spark Plugs with resistors are for reducing or eliminating 'ignition noise' and removing 'Peaks' in current which can have a detrimental affect on running

 

The only reason that resistor plugs are specified in some markets is to comply with that market's electrical interference legislation, not anything to do with the performance of the engine. (Quoting a well-known engine manufacturer)

The thing to avoid is using a resistor plug where there is already a resistor plug cap - then there can, but not always, be erratic performance.

Said engine manufacturer normally supplies HT leads with a plain non-resistor  (unsuppressed) plug connector; hence them specifying a resistor plug for certain markets. 

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On a side note, the Champion plugs worked great in older engines, but do not seem to be as as proficient in newer fuel injected or new design types of engines. I run Champion plugs in my old chainsaws and garden tractors and they run great and burn clean, but I wouldn't put them in my old Volvo 850 or a newer vehicle or engine.

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14 hours ago, Steve2018 said:

Thanks all I went with the Resistor  type NGK resistor gapped to 0.76mm as it was the easiest one to get hold of. 

 

Yep!, if it's recommended, then probably the best way to go. 

I don't know how old your machine/engine is, but B&S quoted the use of both types Res/non Resistor type Plugs, depending on application. This is according to the 1981 version of the workshop Manual.

Modern engine versions in various categories are a different story (Vehicle, Non road, handheld etc), so it's good to see you checked the requirement and asked the question.

 

 

13 hours ago, Wristpin said:

 

The only reason that resistor plugs are specified in some markets is to comply with that market's electrical interference legislation, not anything to do with the performance of the engine. (Quoting a well-known engine manufacturer).

Yep! Legislation has a lot to do with it and interference is another word for Ignition Noise. Many of us can remember the interference on our old 405 line Tellys when an Un-suppressed car went past the house!.    

At the end of the day, manufacturers specify a particular type and we ignore this at our own (possible) cost.

We have to choose who we want to believe, either modern Vehicle engine manufacturers, or Spark Plug manufacturers as to what the (possible) causes of performance issues are from incorrect application-     -NGK-

Kohler Manual also specified Non and Resistor types (as at revision 1992), but also quoted 'RH' for all (then current) models, which may well be as a result of legislation. 

 

   

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3 hours ago, Anglo Traction said:

 Many of us can remember the interference on our old 405 line Tellys when an Un-suppressed car went past the house!.     

 

   

 

:confused:

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Not wishing to be to controversial but my experience shows more capacitor failures with a magneto ignition if used with a resistor plug or a suppressor cap which has the same affect.

Look at http://www.brightsparkmagnetos.com and see the results obtained with a controlled test.

Resistor plugs OK with coil ignition.

Neil

 

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46 minutes ago, Ransomes256 said:

Not wishing to be to controversial but my experience shows more capacitor failures with a magneto ignition if used with a resistor plug or a suppressor cap which has the same affect.

Look at http://www.brightsparkmagnetos.com and see the results obtained with a controlled test.

Resistor plugs OK with coil ignition.

Neil

 

That’s an interesting observation. I’ve always associated condenser failure to be age related rather than resulting from any other influence.These days I rarely work on anything with an exterior ignition coil , slightly more often on machines with exterior “ platform” magnetos and the bulk of the time on flywheel magnetos. I do change a lot of condensers on the latter group but then they are usually 50+ years old.  Not sure.

This lot have been changed in the past 15 months or so.

D2529B99-6D3F-40F3-A368-7502D465ADD4.jpeg

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