anyone know who this is giving plug advise

[don_vanecek]

I recently changed plugs but noted when I got home the auto store gave me D7's instead of D8's search the web for the difference and found this posted, can't tell by who, by the way , my bike sure starts better with the D7's.

home.tiscali.nl/saniris/motor/Sparkplugs.htm

Anyone know who this is??? wonder if they have any other tidbits??? 

[fret not]

7s are the next hotter heat range of NGK plugs.  Yes, a cold engine will start better with the hotter plugs, but don't try to run it hard for any length of time or you can damage the engine.  Best to use what the factory specified.

[kwells]

7s are really fine. We have water cooled engines so they are far more tolerant to the slight increase in heat produced by a plug. D8eas should be ok though. I'd investigate a little bit to see why they aren't working so good. Possibly the plug wires need to be cut back some or new caps are in order.

[The Prophet of Doom]

I have to say that IRIDIUM plugs are the shit - Massive improvement on starting and idling.
They are more expensive, but highly recommended by me.

[vadasz1]

I have to say that IRIDIUM plugs are the shit - Massive improvement on starting and idling.
They are more expensive, but highly recommended by me.

+1


I have Iridiums in mine and it is THE BOMB when starting and for a nice smooth idle.

[Jimustanguitar]

What brand/model iridium plugs are you guys using? (Sorry if it's already in the parts and upgrades section)

[Rikugun]

Interesting tidbit in the article Don referenced as it relates to Iridium plugs. The author warns about using the 5k resistor type (ie DR8EIX) in US models as they allready have a 5k resistor in the cap - maybe the Canadian models too? European models use non-resistor caps. A resistor is required in one or the other to suppress radio interference. I assume he's warning about doubling up on the resistors which works some ignion components overtime and may shorten their life. This is also true of utilizing resistor type wires as the US models are not equipped as such originally.

Regarding the heat range, I was taught one heat range either way would not make a huge difference. Running one range hotter for instance won't result in a holed piston. Anyway, heat range numbers relate to the plugs ability to retain sufficient heat to burn off excess carbon and so should make zero difference to cold starting ease.

Don, I'm surprised you didn't recognize the article? It comes from this website:http://home.tiscali.nl/saniris/motor/motor.htm and the article is "sparkplugs"
Lots of interesting stuff to anyone not familiar with the site. Really interesting is the article "1985-87 RoV" which is a collection of early ROV newsletters. Lots of fascinating reading. Don and NightVision get shoutouts for supplying the back issues Don had saved.

Of particular interest to me is the sidecar Vision and mods as it relates to it's specific needs. It's this bike that inspired me to consider flipping the forks around to a leading axle design. The notion was not received warmly here but it's still on the back burner.  :)

[The Prophet of Doom]

I use the  DR8EIX and Tiger's spark leads and caps

[Rick G]

When I worked in a greasy hole in the wall in Salem OR. we routinely removed the resistors from plug caps and substituted a 1/8 inch of uncoated  brass brazing rod. Those damed resistors  screw up the ignition on old bikes. They are there for radio suppression  and I don't have a radio on my bike !! lol

[QBS]

I've heard  that resistors have the benefit of providing a fatter spark after the reistance has been overcome.  T or F?

[Rikugun]

I'm not sure I'd use the term "fatter" but the added resistance requires a higher voltage to overcome so the spark may be a slightly higher voltage. That comes with a price though. Not only was it not part of the original design parameters, but now those coils and wires are 30 years old.  ???

Rick, you may not have a radio on your bike but the neighbor might in his home and curse you when you come and go. I wonder what effect it would have on GPS units?

[Rick G]

The  theory is,that on older bikes the resistance is so great that it inhibits the the spark and you get a weaker spark, if they are in there. In practical terms , they started easier with out the resistors .  I could never find that the ignition interfered with any radio , with or with out the resistors.. Just don't try to use carbon impregnated plug wire, on an old bike. Copper core multi strand , is far better,

[motoracer8]

 Ristance is a voltage riser, ie the voltage has to overcome the ristance to flow= higher voltage.
If you have 5K ohm plug caps an additional 5k ohms is probbably not going to matter as long as the plug wires and the coils can handle the extra load.

You might want to check the plug caps to see if they are 5k ohms, as they age the ristance can increase.

New NGK plug caps are cheep, and alittle 7mm wire is cheep insurance for a 30 year old motorcycle

A good ignition system cures alot of carburettor probblems.

  Ken G