a spark plug thread - "best" spark plug for a triple?

[beauchemin]

I vote for NGK.  I've used B8ES or B8EV in all my Laverdas.

 

[Terry Dymond]

Ditto, I use B8ES in each of my cylinders :

 

[Paul LeClair]

my current 82 1200 build in progress is stock flat top pistons, A11 cams, and Red's ignition. I haven't decided on coils and wires and caps yet.

next time I go to the dyno with one of the Laverda triples I think I am going to take a variety of spark plug models and brands with me and do some back to back runs to see what the differences actually are.

thanks for all the feedback!

Paul LeClair

 

[Paul Marx]

Depends what fuel and or additives you're using as well I should think.
Paul

 

[lemonjelly]

I thought the ND coils are fine with Reds ignition.

 

[mauricejota7604]

My Nonna 3C cold fouled a plug tonight the bitch, where do you get those B8ETs with the three prong electrodes, I have constant issues with B8ES cold fouling and its pissing me to tears. >

 

[Rusty Spokes]

My Nonna 3C cold fouled a plug tonight the bitch, where do you get those B8ETs with the three prong electrodes, I have constant issues with B8ES cold fouling and its pissing me to tears. >

Got the NGK B8et spark plugs on closeout here in the USA from sparkplugs.com ...NGK discontinued the multiground 8s without the built in resistor. They now offer BR8et..(NGK
#6612) you can find them on Amazon UK, the Bay UK or http://www.sparkplugs.co.uk/

Rockauto here in the USA has them for $5 each. Rockauto Uk has BR8et for 3 pounds each UK.

Rockauto UK has the meteor metal Iridium NGK "8" #5044 for 2.25 pounds each UK.

The NGK BR8eg (#3130) is a good plug with better anti-fouling characteristics about 2.2 pounds each UK in packs of four..or 4 pounds each UK..get three four packs and you have spark plug inventory for years.

Watch the shipping charges and minimum quantities allowed on Rockauto..some stuff is local UK and some is USA..shipping charges could be more than the spark plugs are worth.



http://www.rockauto.co.uk/catalog/raframecatalog.php?carcode=904110&parttype=7054&

I would not worry about the built in resistor..if the spark plugs are fouling and continue with new plugs..could be a HT coil output too low..mixture too rich..timing too retarded at idle..choke plungers not seating well on one or more carbs (I've had new plungers that would not seal well..the rubber tips/seals were dried out on the shelf)

I would use the NGK BR8eg #3130 spark plugs and see how they work out

 

[Yogi]

Rusty,

Is US$ 1.25 each a good price for B8ET?

Yogi

 

[Rusty Spokes]

Rusty,

Is US$ 1.25 each a good price for B8ET?

Yogi

Excellent price..grab them up!!..NGK does not make the multi ground 8s with no resistor (B8ET) and offers the BR8ET now (the R for resistor). The B8ET would be old stock and being sold close out. That's about the price I paid for my Laverda spark plug inventory a while back.

 

[Paul LeClair]

I thought the ND coils are fine with Reds ignition.

after sorting out my boxes of Laverda parts, I have various coils and wires "in stock" so to speak, including used TEC coils, and brand new Dyna green 3 ohm coils, along with a selection of wires and plug caps. I also have three full sets of the stock ND coils/wires/caps including the low mileage set that came with the 82 1200 TS project, nice to have options.... 8) I assume the stock coils would be fine with Red's ignition as long as they are in good condition, but I really don't know one way or the other.

Paul LeClair

 

[Vince]

I used to fit expensive plugs to my throughly warn out hunk of junk XT500 hoping they would help the absolutely painful attempts to start it,funnily enough there no substitute for an engine rebuild.

 

[redax5]

after sorting out my boxes of Laverda parts, I have various coils and wires "in stock" so to speak, including used TEC coils, and brand new Dyna green 3 ohm coils, along with a selection of wires and plug caps. I also have three full sets of the stock ND coils/wires/caps including the low mileage set that came with the 82 1200 TS project, nice to have options.... 8) I assume the stock coils would be fine with Red's ignition as long as they are in good condition, but I really don't know one way or the other.

Paul LeClair

stock ND coils will work fine with our ignition system
way the system is set up it will handle any coil from 2-5 ohms so the stock ND coils at 3 ohms are perfect

 

[Rusty Spokes]

I remember the Ducati that Cook Nelson/Phil Schilling campaigned back in the 70s.... they had some issues with spark plugs, mixture and HP output. Gordon Jennings went out to the local K-Mart and bought some off the shelf Chevy HT coils and installed them on the bike. That one simple change made all the problems in the engine disappear. The original Ducati coils tested fine..but better sparks made all the difference.  No cold running issues, plugs fouling or lost revs on the back straight WFO. Since then I am believer in using the best HT coils you can fit..particularity of an older vintage like our Laverdas.

I like the Dyna coils..great sparks. If your Laverda seems to be sensitive to spark plugs..look at your HT coils.

Gordon was inspired to write up some HT coil testing in "Cycle" magazine with some testing on the output of Honda, Suzuki and other popular Motorcycle/Auto stock HT coils. The conclusion was that motorcycle HT coils are as a group are pretty miserable.

Here is a reprint..enjoy.

http://www.eurospares.com/graphics/engine/TheGreatIgnitionCoilTest.pdf

 

[Paul LeClair]

when I built the 1971 SFC 750 8000 series, I replaced the Bosch coil with a 40,000 volt automotive coil with its decals stripped off. The current owner of the SFC, who owns other SFC's, tells me that the bike I built is the quickest easiest starting SFC he has ever encountered.......  http://www.pertronix.com/prod/ig/flame/coils/40000_volt.aspx The high voltage automotive coil made a huge and noticeable difference to the bike over the original Bosch coil.

Paul LeClair

 

[AndyW]

Hey Paul,
Couldn't find any info on the website: are they 40mm diameter coils or the larger ones you find in cars? I have a few 70s Triumphs  which would benefit from the Flame coils even if they wouldn't fit into the Laverdas.

AndyW

 

[Paul LeClair]

Hi Andy

that was a few years ago, I ordered the coils in from a local auto speed shop, in black bodies, they were either 40,000 or 45,000 volt output, and they were exactly the same body diameter as the original Laverda 750 Bosch coils. I just peeled the stickers off the black bodies, mounted the coils in the original location on the original clamp mounts, only real tell tale for a rivet counter would be that the coil top was black rather than the brown of the Bosch original. Wolfgang even sells the appropriate Bosch coil stickers if you really were determined to disguise the modification...

Paul LeClair

 

[Paul LeClair]

now I am wondering about "ballast resistors" in the coil wiring. My rudimentary understanding is that a ballast resistor typically reduces the 12 volt feed by 3 volts, down to 9 volts.

So, if you buy a "12 volt" coil intended to run with a ballast resistor, meaning it is actually intended to run on 9 volts, then you have to keep the ballast resistor in place, otherwise you will cook the 9 volt coil with the full 12 volts....

Similarly, if you buy a true 12 volt coil intended to run without a ballast resistor, and hook it up in a bike that has a ballast resistor in the coil power feed, the 12 volt coil will seriously underperform as it would only actually be getting 9 volts.

none of these bloody coils seem to be marked, other than some indicate primary resistance like 3 ohms, etc. How the heck do you fins out or figure out whether a coil is actually 9 volt and needs to run with a ballast resistor, or 12 volt and needs to run without a ballast resistor? The whole ballast resistor issue was a "Mickey Mouse" knee jerk "solution to starting a vehicle when the electric starter draw is high and not enough voltage was left over to also fire a coil, so "they" reduced the voltage a coil need to work down to 9 volts....

the original Laverda ND coils I am sure were marginal from day one, they may well still work, but clearly there are higher output voltage alternatives available to us, and clearly there are benefits to firing the plugs with the highest possible voltage and increasing the plug gap.

I am using a Pertronix "E Core" 60,000 volt coil with a Pertronix ignition module in my 1972 Triumph Spitfire car build, I had it in place before the engine threw a rod, and it made a really noticeable improvement to ease of starting, idle, etc. I want something similar for my Laverda triples, yet small enough to be able to be packaged out of sight somewhere on the bike....

For a 120 like my RGS, simple enough to wire three individual auto coils, maybe not so simple to mount and hide them...

For the 180's, I have not as yet seen a dual output automotive coil, anyone know of such a product? I also wonder if using three coils on a 180, with two of the coils wired together to fire together, would work? Subject to mounting location issues, of course.

I also have never seen voltage output figures for the Dyna 3 ohm so called green coils. Anyone know?

it only makes sense to fire the plugs with the highest possible voltage, to a laymen like me anyways, coils are cheap, I would like to use the very highest possible voltage output coils that can be mounted on the bike... Has anyone figured out a great solution? I don't care what brand they are, just the highest possible output voltage that can be fitted on to a Laverda triple bike somehow?

Paul LeClair

 

[Spub]

Correct me if I am wrong (most likely I am), but my impression was that the alternative metals used in sparkplugs were mainly to reduce erosion of the sharp edges of the electrode and core, so that a spark could more readily make the gap....if that is the case, this would have less to do with fouling....On my SFC I also junked the BOSCH coils, and put in an automotive coil like Paul did, in fact I think the generic name is "Flamethrower"and it is generally sold in autoparts stores....may be the same coil Paul used....my experience was the same, bike starts rights up; spark VERY healthy......that being said, I use Dyna coils on just about every other bike, and as Rusty says, these coils also throw out a health spark.....I would be more inclined to make sure I had a very health coil before I worried about the spark plug.....I have had just about everyting spark plug imaginable in all of my bikes at one time or another, and this I can say: I've had failures with just about every type and brand, and successes with every type and brand....

 

[redax5]

Dyna coils are your best option, green coils are a bit bulky but will fit
or use their mini coil series, they state similar output to the green coils anyway

I don't recommend using the ballast resistors at all on any ignition set up, even the original Bosch deal

 

[Rusty Spokes]

I'm sure if the aftermarket HT coils needed a ballast resistor..they would of specified it in the installation instructions. I don't think splitting a HT wire from a single output coil for a 180 will work very well. Dyna makes the dual output coils, illustrated below. Redax is right..the big Dyna coils are bulky but do fit..the mini Dyna coils would be a good choice. They claim about 40,000 volts per output.

Wolfgang sells the Dyna coils..don't know if he has the mini series. Dyna coils are pricey..but if your changing spark plugs often..they are worth it.