Why does the dr have two sparkplugs?

[powerslave73]

Not looking for a smart ass answer either, I'm just curious?

[pacaver]

Due to the size of the bore I believe it's necessary for more complete combustion and lower emissions. A single spark in one spot won't be able to successfully ignite the entire fuel-air mixture. My other bike has a primary plug and a secondary plug and I think it's due to the above reasons.

[mxrob]

Not looking for a smart ass answer either....

Oh sure, take all the fun out of it why don't ya?

[Bob Onit]

Oh sure, take all the fun out of it why don't ya?

Because it has two spark plug holes..

[boatxr]

Not looking for a smart ass answer either, I'm just curious?

i figured it made it that much more of a dead reliable bikes.

what are the chances of both plugs crapping out at once?

you always have another to get you home.

[adams]

i just tell people that it means my bike has two cylinders

[beemerwolf]

when I took my bike to DMV for inspection before licensing, there was a guy training a young lady & he looked over the bike & told her the serial numbers for the frame and engine and then to make twin-cylinder when he saw the engine.

I piped up telling him it was only a single cylinder, opps.....he did not like that, guess I was showing him up in front of this young lady trainee. He looked at the bike again & said---twin-cylinder, mark the form Jennifer!!

I just shut up & waited til they were done!!..their problem, I am just a dumb uneducated motorcycle rider/mechanic of nearly 40 years:p

[dbov21]

That's why they're cops. Now wait until you get get pulled over and they wonder if you have swapped tags/serial numbers with a different bike because of it!!

[bills442]

it's probably for emissions. Lots of cars used to have 2 plugs, they would stagger the spark in the hopes they could burn some of the unburnt gasses; I seriously doubt it adds any power, but might make it a little cleaner at the tailpipe. extra weight and complexity and coils to go bad I imagine, in the interest of EPA again.

[portegee]

This weekend I was doing a little maint on the bike and when I pulled the spark plug wires and the one closest to me was shatterd, the only thing I could think of was the oil from my rocker cover leaking hit a really hot spark plug and bam it was shattered I believe if there was only one spark plug I would have been out of luck wherever it had broken, but I couldn't tell the difference in performance after I put in the new set, and I don't know how long it had been like that. So for me it just helps add to the stone reliabilty of this monster

[mxrob]

This weekend I was doing a little maint on the bike and when I pulled the spark plug wires and the one closest to me was shatterd, the only thing I could think of was the oil from my rocker cover leaking hit a really hot spark plug and bam it was shattered I believe if there was only one spark plug I would have been out of luck wherever it had broken, but I couldn't tell the difference in performance after I put in the new set, and I don't know how long it had been like that. So for me it just helps add to the stone reliabilty of this monster

Yikes! Well, if your bike is indeed "Bone stock with the air box opened up", as your signature states, I guess I can see the ceramic portion of your plugs being so hot that any fluid contact could cause them to shatter. Are you running the stock CR10e'?

[500XC]

The DR has two plugs because Top Fuel Hemis have two plugs!

Truthfully, the twin plug design promotes a more efficient burn than the single plug design in a hemispherical combustion chamber.

More efficient burn, more power!

[canon del cobre raider]

Not looking for a smart ass answer either, I'm just curious?

REALLY THINK THAT THE DR HAS TWO SPARK PLUGS BECAUSE IF THEY PUT ONLY ONE ALL THE COMPRESSION WILL BE LOST TROGUHT THE OTHER HOLE,?

[KnotHead]

Nah... You guys have it all wrong. The DR has such a large piston that a normal ignition wouldn't work.

One plug is positive and the other negative, when it sparks it actually arcs between the two plugs. I've heard that it's so hot you can shut off the gas and the spark alone will heat the air enough to run the motor... but you need the fuel to control temps so the piston won't melt....

Really, it's true!

[portegee]

Yikes! Well, if your bike is indeed "Bone stock with the air box opened up", as your signature states, I guess I can see the ceramic portion of your plugs being so hot that any fluid contact could cause them to shatter. ? Are you running the stock CR10e'?

Actually the ones I had in there where the CR9 either R or E I can't remember, but I did replace them with the CR10E. I have the snorkel removed, but the PO drilled big holes all over the air box so I closed them up with some 200 mph tape and richened up the pilot screw as well other than that the bike is stock, it just dosn't make the header glow anymore

[rodie427]

i like when the header glows, I can light a smoke if i forget matches ?

my guess is that it is for emissions, just like the HEMI's

What does everyone run for sparkplugs ? Stock machine

[mxrob]

i like when the header glows, I can light a smoke if i forget matches ?

my guess is that it is for emissions, just like the HEMI's

What does everyone run for sparkplugs ? Stock machine

96-09 DR650SE... CR10E (stock), CR10EK (dual ground electrode, I'm currently running these) CR10EI (the new Irridium plug that is supposedly available) These are NGK numbers.

[NordieBoy]

What does everyone run for sparkplugs ? Stock machine

CR10EK

[Gregory burnette]

Hey guys I want a smart ass answer or just any answer will do.I just bought a Suzuki from a pawn broker and they said it was a dr 250-500 they wasn’t sure.I got the vin number but it looks to be missing some numbers.can anyone help and figure out what this bike is ? Vin JS  41A3X2100452 that’s the best I can make out 

[plugeye]

28 minutes ago, Gregory burnette said:

Hey guys I want a smart ass answer or just any answer will do.I just bought a Suzuki from a pawn broker and they said it was a dr 250-500 they wasn’t sure.I got the vin number but it looks to be missing some numbers.can anyone help and figure out what this bike is ? Vin JS  41A3X2100452 that’s the best I can make out 

i answered this on your other post