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What's a good spark plug to run? B9ES ?

Posted: Fri Apr 14, 2017 8:26 pm
by pepsi
What's a good spark plug to run? NGK B9ES ? BR9ES? Maybe a little hotter? B8ES?

Re: What's a good spark plug to run? B9ES ?

Posted: Fri Apr 14, 2017 9:27 pm
by the KR kid
Had B9ES in mine; it's also the listed plug in the parts book.

Re: What's a good spark plug to run? B9ES ?

Posted: Fri Apr 14, 2017 10:22 pm
by pepsi
had the bike quit, installed new B9ES plugs and all is good again. turn up the sound!

https://youtu.be/jdl2iBiM3_0

Re: What's a good spark plug to run? B9ES ?

Posted: Sun Apr 16, 2017 2:52 am
by James P
If you want to use a plug with the same heat range, you might like to try B9EG, B9EV or B9EGV. These all have thinner electrodes, so are more resistant to fouling. Because the electrodes are thinner, they have to be made from more durable material than the copper electrodes of ES plugs, which means the EG/EV/EGV plugs tend to last longer. Of course, they are a bit more expensive!

The EG plug has a 1.5mm diameter electrode and is usually about one-and-a-half times the price of an ES plug. The EGV has an electrode of 1mm diameter and usually costs about twice the price of an ES plug. The EV variant also has a 1mm electrode, but I believe it is no longer made (you can probably find suppliers with NOS plugs though) - price may be a little less than EGV.

All these plugs are also available with resistors (BR9EG etc.), which should be chosen if you are using plain (non-resistor) plug caps.

Regards,
James

Re: What's a good spark plug to run? B9ES ?

Posted: Sun Apr 16, 2017 2:42 pm
by pepsi
James P wrote: Sun Apr 16, 2017 2:52 am If you want to use a plug with the same heat range, you might like to try B9EG, B9EV or B9EGV. These all have thinner electrodes, so are more resistant to fouling. Because the electrodes are thinner, they have to be made from more durable material than the copper electrodes of ES plugs, which means the EG/EV/EGV plugs tend to last longer. Of course, they are a bit more expensive!

The EG plug has a 1.5mm diameter electrode and is usually about one-and-a-half times the price of an ES plug. The EGV has an electrode of 1mm diameter and usually costs about twice the price of an ES plug. The EV variant also has a 1mm electrode, but I believe it is no longer made (you can probably find suppliers with NOS plugs though) - price may be a little less than EGV.

All these plugs are also available with resistors (BR9EG etc.), which should be chosen if you are using plain (non-resistor) plug caps.

Regards,
James

Thanks , I might have a high float level problem causing some fouling issues. I left the petcock on prime and had fuel leaking out the overflow(s). It runs real strong on top but gets all monkeyed up down low. However it does not seem to have problems sitting and idling?

Re: What's a good spark plug to run? B9ES ?

Posted: Tue Apr 25, 2017 9:18 pm
by pepsi
James P wrote: Sun Apr 16, 2017 2:52 am If you want to use a plug with the same heat range, you might like to try B9EG, B9EV or B9EGV. These all have thinner electrodes, so are more resistant to fouling. Because the electrodes are thinner, they have to be made from more durable material than the copper electrodes of ES plugs, which means the EG/EV/EGV plugs tend to last longer. Of course, they are a bit more expensive!

The EG plug has a 1.5mm diameter electrode and is usually about one-and-a-half times the price of an ES plug. The EGV has an electrode of 1mm diameter and usually costs about twice the price of an ES plug. The EV variant also has a 1mm electrode, but I believe it is no longer made (you can probably find suppliers with NOS plugs though) - price may be a little less than EGV.

All these plugs are also available with resistors (BR9EG etc.), which should be chosen if you are using plain (non-resistor) plug caps.

Regards,
James
Why should I use resistor plugs with non resistor caps? Would having no resistors anywhere make the bike run funny?

Re: What's a good spark plug to run? B9ES ?

Posted: Wed Apr 26, 2017 11:16 am
by James P
pepsi wrote: Tue Apr 25, 2017 9:18 pm Why should I use resistor plugs with non resistor caps? Would having no resistors anywhere make the bike run funny?
It shouldn't really matter, as long as you have a resistor somewhere in the circuit. The function of the resistor is to stop your ignition system affecting radio and television receivers in the area you are riding (or at least drastically reduce the effects) - it shouldn't necessarily affect the running of the bike.

Personally, I usually use plain spark plugs with resistor caps. You should get exactly the same effect using resistor plugs with plain caps. I'm not sure what the result will be if you use a resistor cap AND a resistor plug - it may vary depending on your set-up. Some bikes use this arrangement as standard, so you could find it makes no difference.
The most popular resistor size is 5k ohms, but plugs and caps are also available with 2k ohm and 10k ohm resistors.

Of course a greater value of resistance will reduce the energy dissipated in the spark (less current), but I have no idea how much resistance an ignition system will tolerate before performance is affected - I presume it will depend on various parameters (e.g. ignition voltage, plug gap, combustion pressure, type of fuel etc.).

Regards,
James

Re: What's a good spark plug to run? B9ES ?

Posted: Wed Apr 26, 2017 1:56 pm
by pepsi
The reason why I asked is because the PO changed out the plug wires and I do not know if they are resistor or non resistor types.