spark plugs

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rocker1

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Hi All

I have a 1976 850 mk3

I have just had fitted a complete wiring harness with Boyer ignition, twin output coil and a powerbox.

My Question is; Has anybody any experiance to share as to the best spark plugs to use with Boyer ignitions? I have heard that Champion work well but I use a Splitfire in my Gold Star and wonder if they are also good for electronic ignition.

Regards Bob.
Lee on Solent UK.
 
Uh boy. A sparkplug thread :roll:

Champions work for me.
 
I don't think the brand makes any difference at all, as long as the engine is well sorted and tuned.
 
Hi,
I prefer Champions.
I had a lot of trouble with NGK breaking down but it may have been due to a rich mixture.
Leaving the choke on too long while warming up does not help.
Mine seems to run sweetly now with champions BUT I always carry a brand new pair of spares with me.
Like someone said, if all is set up well both should work but I would still put new spares in your side panel with a plug spanner.
Cheers Don

PS, ive just got my Norton Calendar from the NOC website & its really nice.
Cheers Don
 
I've had really good luck with NGK BP7ES Iridiums. It has eliminated any fouling issues I was having and provides a good spark. I used to have to swap out plugs frequently, but haven't had to for 2 seasons now. Granted, before I started using them, I was still dialing in my carbs and getting the electrical sorted out.
 
When I 1st got me a running Combat in '99 its Amals were worn or jetted rich and guides leaked enough foul Champion plus over couple of heat ranges. I didn't even know where the points were at that time let alone whats inside an Amal. So looked up cross reference for Bosch Platiinum 4 electrode plugs for no more fouling misfiring till I rebuilt it soup to nuts into Ms Peel who continued to run Bosch Platinum 4's. Cheaper 2 electrode might of been better, don't know, couldn't tell.
 
I have used Champion and NGK. I have been using the NGK BP7EES for quite a while with Boyer and Sparx ignitions and have had no issues to speak of.
 
I have always figured a plug was a plug. I just look for shiny plated threads for best life of the cylinder head threads.

I have seen a consistent gain of about 1/2 horsepower when using plugs with multiple ground electrodes. Don't know why. Jim
 
Boy it takes a darn good dyno to detect .5 hp change out of say 60 or so total.
I'd like to learn more of that in a new thread.

BEST EVER plug I found was the JCWhitney sold surface discharge type that had a sprocket like ring of electrodes facing center electrode with a insulator filling to make it all about flush. I found they solved the rich plug fouling tune in my drag only P!! being used in college campus and surrounds at low speed alot. Boy Howdy did they register on my joint strain gauges and time annoyance of farting crappy running to leave a traffic light... Also allowed better safety to turn the intersections as that required an off idle leap to middle then a blip of tire spin to aim rear around then a bit slower twist to get on out of there w/o just smoking in place. A stumble doing that could cause a sudden hi side from a non leaned attitude so extra distance launch attitude. I may need em in Ms Peel.

http://www.ngkntk.com.br/site_ingles/direct/p12.html
http://www.ngksparkplugs.com/products/s ... urface.asp
http://www.eng-tips.com/viewthread.cfm? ... 82&page=24

spark plugs
 
Most modern dynos are accurate to around 1/10th horse. The problem is ambient conditions can change enough from one run to the next to make at least several tenths difference. Jim
 
the NGK ones noted above are just fine.
Do you know what a spark plug does?
It can't do that if the EI doesn't close or open the coil primary winding.
I find the lack of individual cylinder adjustment with EI to be unacceptable.
It may be my lack of understanding.
We need 200 rpm to wake up the EI I'm told.
At 40F the 50W oil in my MK111 along with the reduced battery capacity is nothing but a starting frustration.
Air fuel mixture, compression, spark at the right time.
My EI is supposed to control spark at the right time, I hurt my foot yesterday if that says anything.
Above 60F all is well.
Do you use the electric leg? Does it ever get below 60F at your location? Are you sure you want that EI?
Rant off.
the NGK ones noted above are just fine.
 
Autolite makes the AP64 in new double platinum it is a bit more money but can be found on sale. Part # APP64 these have plated bodies now so no rust. I have never hurt these tough plugs. They are deemed to harsh by some causing more vibration out of the motor. I call that running better maybe it’s just me. Found at: Wal-Mart, Advance Auto here in the states. With an E.I. and a high quality coil can be gapped at .035. Also are very good for leaner burning mark2 carbs. Caution may cover up your bad tuning. Use NGK’s to find bad tuning I find they sputter if just a bit lean or rich.
If you like mellow go for the old style WRP7 Botch Platinum with the small center wire. It’s a very smooth but tough plug that has the best double plating.
Of course you must do your own testing I get more top end out of the APP64’s than any other. YMMV
 
Well put 78 miles Fri on new AP64's w/ rebore Amal MkI's
All was great performance wise.
Works in this ole combat.
BTW broke 10,000 mile mark on my speedo. :mrgreen:
Marshal
 
I keep switching between the same old NGK and Champion plugs that I have sitting in my parts drawer for the last 20 years when ever I seem to be having starting problem or bike runs badly. Solution always turns out to be a problem with something other than the plugs! So my assumption is, if you have spark and everything else is in good running order, doesn't matter what brand spark plug you use that's been approved by manufacturer. But can a bigger spark really increase performance or once fuel mixture ignites. :roll:
 
"But can a bigger spark really increase performance or once fuel mixture ignites."

No it doesn'/can't. It takes X volts to jump the gap. If it takes, say, 20kv, then that's all it takes and having a system that can deliver a bajillion KV doesn't do a darn thing. OTOH, as the plug gap widens with wear and the required voltage goes up, a system that can deliver more voltage, can still fire the plug when perhaps the oem ignition could not. BUT, this would occur at a point well beyond the recommended plug gap. The other case where a higher voltage system may be helpful is if the compression is increased beyond OEM OR there is an extremely rich fuel/air mixture. Higher compression/excessively rich mixturesrequires more voltage to jump the same gap.

But adding a high performance ignition system to a stock engine in proper tune will do absolutely nothing as far as performance improvement is concerned.
 
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