Dogsoldier
Well-Known Member
On the phantom, I started to use a B6hs plug but got to thinking about the CDI. Seems to me I should use a resistor plug like a br6hs to keep from smokin the CDI, plus I use my iPhone as a speedometer. What say you?
Correct spark plug
- Thread starter Dogsoldier
- Start date
NGK-BR6HS is the plug of choice around here, although I use the NGK-BR8HS, (colder plug), myself here in the high heat of the high desert at 4500 ft elevation on both of my Phantoms.
I don't think that resistor or non resistor makes much difference on the CDI, but I can tell ya what the non resistor screws up on ya...lol.
I have a wireless speedometer bike computer I have been running for a few years now and it was telling me I was going 99 MPH as I was sitting at a stop sign...lol...lol.
My previous speedo was wired and didn't have that problem, being an ASE certified mechanic in another life, (before my second retirement...lol), I knew it was because of the plug, that is when I went to resistor plugs only for my bikes.
Using your iPhone may or may not have the same electrical/electronic interference issue as well.
I always run resistor plugs for the same reasons. On the Phantom I always ran an NGK BPMR7A plug (part Number 6703) which is the same plug ran in the Stihl saw the Phantom cylinder was based on. It doesn't have any thread stick-out like the B6HS and similar plugs do, which reduces hot spots and also improves the heat dissipation efficiency of the plug, which means a hotter plug can be run without issue. That helps neutralize the fact that the plug I like has a projected electrode, which generally acts as a slightly hotter plug than the heat range number suggests.
That greatly depends on the coil. Less resistance across the secondary circuit means a faster discharge rate, which can cause the coil to run a bit hot. I've seen more than a few coils get burned up, especially on a 2 stroke, because of that. That is why many engines that don't have resistor plugs from the factory will often have a resistor in the plug cap on the wire, or built in to the discharge from the secondary coil.
I'm guessing that the Phantom 85 may not have either of those features of the resistor in the cap or the secondary coil since only the resistor plug was needed to get an accurate read out from my speedo???
Dogsoldier
Well-Known Member
Thank you ! You guys are awesome!
Your very welcome, your awesome too...lol.
Dogsoldier
Well-Known Member
Resistor it is!
I am pretty sure it doesn't. I know it doesn't have one in the plug cap as I took it apart to check, but I can't 100% say so for the coil in the CDI unit.
View: https://giphy.com/gifs/reactionseditor-yes-awesome-3ohzdIuqJoo8QdKlnW
Anything is better than the Torch plug it comes with.
