spark plugs

What would be a good set of performance plugs to use with 134 hp / 10:8 comp, (what gap, .030 or .040)

I'm running NGK DCPR8E (one step colder)in my 80" Evo at 10.5:1 static, gapped at .035...Generally when you raise compression you can narrow the gap.

Why use non oem plugs?

I pulled the plugs, approx 700 miles. ( 3% ) was getting it on. NKG"s DCPR8E looked Darn good, gap was approx .029. After looking at plugs was satisfied. However gonna try autolite just for comparison.

Yeah,only real difference in any standard spark plug is solid cap or screw on...Screw on one's can get loose or corrode....A solid cap standard plug is better IMO....I've fouled a few plugs, but I've never wore one out

The NKG DCPR8E look so good, I wire brushed them lightly to clean them up a bit and put them back in the bike. Is there a certain protective coating I may have harmed ? Whats up with the E3 plugs thats being touted ? I hear accel is the better of the two.

Snake oil IMO. No performance gain in those fancy expensive plugs. A sharp bright blue spark is what you want to ignite the mixture. Doesn't make any difference what type of plug provides that spark.

Autolite are super good plugs.
But do not use irridium plugs.
That is where you get interference.

in metric bikes run NGK.

Thunder-Max & somebody told me not to run irridium.

Also had a dyno man say he had dynoed the same bike with every brand of spark plug made.
He likes the standard Autolite 4164. Which is like a 2.00 spark plug,

He gained nothing with irridium.

But you run what you like.

I run the same plug in my new roadglide and on the old bagger never had any issuie with them on the dyno .also ran the se plugs either one worked never had any retard issues with these I did have it with the original champions.

Champion Plugs are about the bottom of the barrel.

I don't remember the problems in why not to run them. But I do remember it.
And you gain nothing by running the more expensive iridium plugs.

There is talk all over the internet about plugs.
Trying to get the right comments
But I dude that builds bikes and dyno's them is where I got my info.
I ran the iridium plugs for a while. And never got anything from them.

Dude 30 miles up the lake graduated years ago from MMI.
They told him NGK for metric bikes. Autolite for Harleys.



I will stick with my Autolite 4164

http://harleytechtalk.org/htt/index...ml?PHPSESSID=41483fa98bc1dc3d4393cb6d8a804a9f

OK this is what I can tell ya being a Drivability technician .engine builder .the Iridium or platinum tip plugs with the small electrode just last longer and jump the gap easier that's it .so really the only thing you gain is the coil has to do less work .unless you have a multitude discharge ignition system you are not going to gain any more spark in that cylinder that the coil is able to make as far as stored energy is concerned.no as far as plugs go you only have 3 or 4 manufacturer making plugs for all the labels you buy .allied signal builds plugs for many manufacturers.including autolite and Delco .gm is no longer affiliates with ac Delco they are now to separate companys..federal mogul builds champion and other private label plugs.NGK and ntk build plugs and o2 sensors for various private labels also. And different motor company's. If your looking for engine power it's not in the plugs. And ps champion is the factory plug for HD .

I just change the plugs about every 9 or 10 months.
I tried the iridium.
One of them burnt some of the gap off.
Till I was told by T.M
& a guy that builds motors & is a dyno man to just run the standard autolites.
So I didn't go back with the iridium plugs.

If you like em run em .
But why pay the price got iridium when ya can run the standard plugs & save money.