Direct Fire Plugs

[bigredder]

I was just wondering if anybody had a parts number for a direct fire plug for my 1985 Honda 250es Big Red. Any help on locating a plug would be greatly appreciated. Thanks.

[250rRoostmaster]

NGK DR8ES-L is what you need...

[bigredder]

That's what I am currently running in it but I just wondered if they made a direct fire plug for it or if they used to.

[briano]

What is a direct fire plug?

[bigredder]

A direct fire plug is a spark plug with no ground electrode. The spark just goes from the middle of the spark plug to the outer rim of the plug. Couldn't find pics on the internet but I'll get some when I get home. They are pretty neat.

[86125m]

Hmmm I don't know these older bikes were not made to run on those types of plugs. Just run a regular NGK plug and you should be alright.

[BOB MARLIN]

Those plugs you describe are used on some of the older 2 stroke engines (mostly boats) to help with fouling. I've never seen one used in a four stroke engine.

[YTZ drew]

The common term for that type of plug is a surface gap plug. They are the coldest heat range available, "off the chart" on the cold end of the spectrum when compared to the coldest conventional plug offered. As previously stated, the original applications are vintage 2-stroke outboards and also some rotary engines. A friend of mine used to run them in his Datsun 240Z road race car. On the track they were ok, but would foul as soon as he tried to let it idle for more than a few minutes. He stopped using them when he switched to pistons that didn't have massive domes (the only reason he ran those plugs in the first place).

I have never seen them in the 12mm size you are seeking, only the common 14mm size as found in most cars.

[muthey]

there was a newer type that was made in the last 15 years that was a ovaled ground that fired in 360* but one of the major manufacturers bought his product out from him and closed shop on it so it was available for a very brief time my father in law showed them to me 4 years ago and when we looked for them online found they were no longer available. You are better off running the ngk plug I stay away from the honda branded plugs as I have observed they have a thinner ground plug on them.

[onformula1]

I would stick with the NGK they make the best plug, ND is a distant second.

If you want to goof around a little clip the ground strap down to the center of the electrode.

(It will open up the spark front)

You probably won't feel any difference & it will not turn into a 250R killer :lol:

[bigredder]

I would stick with the NGK they make the best plug, ND is a distant second.

If you want to goof around a little clip the ground strap down to the center of the electrode.

(It will open up the spark front)

You probably won't feel any difference & it will not turn into a 250R killer :lol:

I could beat any 250r with it... In my dreams! lol :lol: