Topic: A couple questions (plugs and leads)

[buffaloejon]

So both of these are listed in the FAQ's, and I hate to keep creating topics, but that's the whole point of the forum is to ask/answer questions. So...

I have Champion RA8HC's right now. That's nothing at all like I've read should be in them. They're used in conjunction with accel coils and leads, so how can I check whether or not they should be resistance plugs? And then what plugs should I use from here on out?

And according to the FAQ, I shouldn't use 3 ohm coils. Has anyone really had problems with 3 ohm coils and the stock points?

[Deltarider]

Has anyone really had problems with 3 ohm coils and the stock points?

You can do that, but the points will burn a bit faster. You can overcome this by having an 1 or 1,5 Ohm ballast resistor in the 12V lead to the coils. Hondaman sells them as a pack.

[buffaloejon]

What do you mean burn a bit faster? As in they'll go bad faster?

[Deltarider]

Yep, pitting goes faster as points have to switch more current. A ballast resistor is a good solution. I remember the days for cars Bosch had standard coils (blue, ca 4,5 Ohms) and socalled supercoils (red, 3 Ohms with a 1 Ohm ballast resistor attached.

[buffaloejon]

Ok, what about the spark plugs? What plugs should I use, and what resistance should the leads be?

The leads and caps together are reading about 6.8 kOhm, so I'm guessing the Champion RA8HC's are the wrong plugs.

[TwoTired]

From coil output to spark gap, you want 5K to 10K series resistance.
It doesn't matter if it is in the spark plug, the spark plug cap, or within the connecting lead from coil to plug.

The number in the spark plug refers to the heat range.  Since you didn't say what bike you have, all I can do is make you aware of the cross between MFGs.  550s normally use a hotter plug than the other SOHC4's.

[buffaloejon]

Ahh sorry, I've got a 76 750K

So which plugs should I use exactly? NGK D8EA or equivalent? I'm pretty much not trying to mess up on something this simple.

[ekpent]

The R code on the champs means they are resistors. Pop in a set of recommended NGK's for starters as you seem to be dealing with a multitude of problems from the dead 1-4 Dyna to that cracked points I think you pictured. The engine will not blow up and at least you will have 4 fresh soldiers in there to do battle as you progress along on the journey.

[buffaloejon]

Ahh thanks a ton, I'll pick up a couple sets tomorrow after work and pop em in.

[TwoTired]

The CB750s use NGK D8EA For summer use.  For winter, D7EA makes cold operation better.

You can use the chart to determine which Champions to use if you prefer those.

I loved the Champions in the 60's for the Chevy small block.  But, was very disappointed with them in the SOHC4 in the 70s.  I haven't tried them in the SOHC4 again, since I'm pretty happy with how the NGKs work/hold up.  I very much doubt that the Champion plugs of today are made with the same process (or even materials) as they used 30 years ago.  Brands don't have to keep the same recipe for a product, and it can change at their whim or desire to increase their profit margin.

I did try Densos, and I had one of the 4 plugs quit on me after a couple K miles.  I don't know exactly why.  (Maybe because my blast cabinet became in-op?)   They aren't as easy for me to get as the NGKs.  So, I'm glad that the NGK plugs work well for me.

Cheers,