« previous next »
Pages: [1]   Go Down

Author Topic: NGK Plug Wars: D7EA vs. D8EA  (Read 23923 times)

0 Members and 1 Guest are viewing this topic.

Offline gravano

  • Full Member
  • *
  • Posts: 71
NGK Plug Wars: D7EA vs. D8EA
« on: April 19, 2010, 10:50:07 AM »
I have D8EAs installed in my 75 CB550f. They run great once started, but it takes about 40 kicks to start my bike. It's in the 50s right now in Chicago. Will a switch to D7EAs render a marked difference? My timing is set right and the carbs are clean. I need to pull the plugs to get a better read on how it's running, but just curious if people have noticed a big difference between the two plugs -- enough to suggest I don't have other problems to diagnose.

Thanks
Logged

Offline Frankenkit

  • Industrial Strength
  • Really Old Timer ...
  • *******
  • Posts: 6,525
  • 2012 CBR250R, 72 CL350, Member #4600
Re: NGK Plug Wars: D7EA vs. D8EA
« Reply #1 on: April 19, 2010, 10:53:24 AM »
7s burn hotter and will help when its cold out, but you'd want to switch back to 8s when it gets hot out.
Logged
"Moderation in all things - especially moderation. Too much moderation is excessive. The occasional excess is all part of living the moderate life."
2012 CBR250R "Black Betty"
1980 CB650c- (sold) Delilah
1973 CL350- Lola?
Quote from: The_Crippler on July 19, 2010, 07:58:02 PM
Sweet, bubbly, Buddha - Say it ain't so!!!
Stuff for sale

Offline mlinder

  • "Kitten Puncher"
  • Really Old Timer ...
  • *******
  • Posts: 5,013
  • Stop Global Tilting now!
    • Moto Northwest
Re: NGK Plug Wars: D7EA vs. D8EA
« Reply #2 on: April 19, 2010, 11:10:09 AM »
They will not help you start the bike more easily. They will only help it warm up more quickly once started, and remove less heat from the head while moving.
Logged
No.

Offline TwoTired

  • Really Old Timer ...
  • *******
  • Posts: 21,802
Re: NGK Plug Wars: D7EA vs. D8EA
« Reply #3 on: April 19, 2010, 11:16:03 AM »
Why are you running the D8s when the recommended plug is D7?

I hated D8s in my 550's.  They became cold blooded b@stards.

Battery fully charged?
Good points?
Gapped correctly?
Timing correct?
Good plug caps?
HT leads cracked?
New condensers?
Logged
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline Duke McDukiedook

  • Space Force 6 Star General
  • Really Old Timer ...
  • *******
  • Posts: 12,688
  • Wish? Did somebody say wish?
Re: NGK Plug Wars: D7EA vs. D8EA
« Reply #4 on: April 19, 2010, 11:16:16 AM »
You should probably check your valve clearances if you are having that much trouble getting it started.
Logged
"Well, Mr. Carpetbagger. We got somethin' in this territory called the Missouri boat ride."   Josey Wales

"It's Baltimore, gentlemen. The gods will not save you." Ervin Burrell

CB750 K3 crat | (2) 1986 VFR750F

Offline gravano

  • Full Member
  • *
  • Posts: 71
Re: NGK Plug Wars: D7EA vs. D8EA
« Reply #5 on: April 19, 2010, 11:54:20 AM »
The D8EAs were on the bike when I bought it. I didn't realize till recently.

Points and Timing are good. Not sure about the resistor caps; one has quite a bit of give.
The battery is charged, but I may replace soon. The guy I bought it from put in a new one in last year, but I think it may still need a new battery.
Logged

Offline Tretnine

  • Prove it,
  • Hot Shot
  • ***
  • Posts: 577
  • Figuring it out, one expletive at a time.
    • http://www.behindbarsmotorcycle.com/
Re: NGK Plug Wars: D7EA vs. D8EA
« Reply #6 on: April 19, 2010, 12:58:49 PM »
I thought 8s were stock on all 550s. No?
Logged
http://www.behindbarsmotorcycle.com/

2009 Kawasaki Concours, 1978 cb550k, 2006 BMW F650GS

Member of the AMA

Offline TwoTired

  • Really Old Timer ...
  • *******
  • Posts: 21,802
Re: NGK Plug Wars: D7EA vs. D8EA
« Reply #7 on: April 19, 2010, 01:15:04 PM »
Quote from: Tretnine on April 19, 2010, 12:58:49 PM
I thought 8s were stock on all 550s. No?

No.

Owner's manual states D7ES, (NGK superceded the number with D7EA)
Or Denso X22ES.

I think all the other SOHC4s used D8 standard.  Not the 500 or 550, though.
Logged
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline BobbyR

  • Really Old Timer ...
  • *******
  • Posts: 12,364
  • Proud Owner of the Babe Thread & Dirty Old Man
Re: NGK Plug Wars: D7EA vs. D8EA
« Reply #8 on: April 19, 2010, 01:28:01 PM »
On the 750 in the Owners Manual they advise the 7s below 40F. Other than that they recommends 8's.
Logged
Dedicated to Sgt. Howard Bruckner 1950 - 1969. KIA LONG KHANH.

But we were boys, and boys will be boys, and so they will. To us, everything was dangerous, but what of that? Had we not been made to live forever?

Offline Tretnine

  • Prove it,
  • Hot Shot
  • ***
  • Posts: 577
  • Figuring it out, one expletive at a time.
    • http://www.behindbarsmotorcycle.com/
Re: NGK Plug Wars: D7EA vs. D8EA
« Reply #9 on: April 19, 2010, 02:38:50 PM »
Quote from: TwoTired on April 19, 2010, 01:15:04 PM
Quote from: Tretnine on April 19, 2010, 12:58:49 PM
I thought 8s were stock on all 550s. No?

No.

Owner's manual states D7ES, (NGK superceded the number with D7EA)
Or Denso X22ES.

I think all the other SOHC4s used D8 standard.  Not the 500 or 550, though.
[/quote

This is news. I'm running a couple of 78 550s and it looks like I need to move to hotter plugs on both.
Logged
http://www.behindbarsmotorcycle.com/

2009 Kawasaki Concours, 1978 cb550k, 2006 BMW F650GS

Member of the AMA

Offline gravano

  • Full Member
  • *
  • Posts: 71
Re: NGK Plug Wars: D7EA vs. D8EA
« Reply #10 on: April 19, 2010, 04:26:29 PM »
Well if it wouldn't affect the starting of the bike maybe I'll leave them in if they don't look too gunked up. This'll leave the resistor caps and battery as prime suspects for the 40-kick start problem. 
Logged

Offline mlinder

  • "Kitten Puncher"
  • Really Old Timer ...
  • *******
  • Posts: 5,013
  • Stop Global Tilting now!
    • Moto Northwest
Re: NGK Plug Wars: D7EA vs. D8EA
« Reply #11 on: April 19, 2010, 04:40:55 PM »
No, carbs, timing, valves and compression are the most likely suspects.
Logged
No.

Offline Duke McDukiedook

  • Space Force 6 Star General
  • Really Old Timer ...
  • *******
  • Posts: 12,688
  • Wish? Did somebody say wish?
Re: NGK Plug Wars: D7EA vs. D8EA
« Reply #12 on: April 19, 2010, 06:03:43 PM »
Quote from: mlinder on April 19, 2010, 04:40:55 PM
No, carbs, timing, valves and compression are the most likely suspects.

+1000.  :)
Logged
"Well, Mr. Carpetbagger. We got somethin' in this territory called the Missouri boat ride."   Josey Wales

"It's Baltimore, gentlemen. The gods will not save you." Ervin Burrell

CB750 K3 crat | (2) 1986 VFR750F

Offline Frostyboy

  • Retired: Never was an
  • Expert
  • ****
  • Posts: 1,227
  • Circa 1951
Re: NGK Plug Wars: D7EA vs. D8EA
« Reply #13 on: April 19, 2010, 07:00:02 PM »
Quote from: Dukiedook on April 19, 2010, 11:16:16 AM
You should probably check your valve clearances if you are having that much trouble getting it started.

Quote from: Dukiedook on April 19, 2010, 06:03:43 PM
Quote from: mlinder on April 19, 2010, 04:40:55 PM
No, carbs, timing, valves and compression are the most likely suspects.

+1000.  :)

+ yet 1 more  ;)
Remove the tank and try and start it cold whilst looking for stray H/T leakage from the plug wires. Do it in the dark so you can see the sparks. Mine was jumping to ground in a couple of places.
« Last Edit: April 19, 2010, 07:04:22 PM by Frostyboy »
Logged
Last year I joined a support group for procrastinators.
We haven't met yet.
[CB550F1]

Offline Gcolgett

  • Full Member
  • *
  • Posts: 35
Re: NGK Plug Wars: D7EA vs. D8EA
« Reply #14 on: April 19, 2010, 07:11:38 PM »
Has anyone else used Champion R6G plugs? I went to Mexico and at times ran at 105+MPH and the CB550F never had a problem using them. Now they are hard to find since they are no longer made. They were a hotter plug than stock. George Colgett :)
Logged

Offline TwoTired

  • Really Old Timer ...
  • *******
  • Posts: 21,802
Re: NGK Plug Wars: D7EA vs. D8EA
« Reply #15 on: April 19, 2010, 08:53:38 PM »
In hot weather and running hard, you actually want a colder plug to help get heat out of the chamber. FYI

I always used Champion plugs in my Chevy engines to make better power.

I was surprised when they didn't work as well in the Honda 550, and certainly didn't make the good power for as long as the NGKs did.  I haven't run Champions in the bike since the early 80s, based on that experience.
Logged
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline gravano

  • Full Member
  • *
  • Posts: 71
Re: NGK Plug Wars: D7EA vs. D8EA
« Reply #16 on: April 20, 2010, 07:35:09 AM »
Quote from: mlinder on April 19, 2010, 04:40:55 PM
No, carbs, timing, valves and compression are the most likely suspects.

Thanks everyone for the plug info. My bike kicks over a lot easier (10 kicks instead of say 40) with the choke fully open and the throttle open a little bit. I'm hoping this doesn't point to valve adjustment; I have big hands and lack that knack for precision that others seem to have. But does the diagnosis point that way?
Logged

Offline Duke McDukiedook

  • Space Force 6 Star General
  • Really Old Timer ...
  • *******
  • Posts: 12,688
  • Wish? Did somebody say wish?
Re: NGK Plug Wars: D7EA vs. D8EA
« Reply #17 on: April 20, 2010, 07:52:35 AM »
Yes.
Logged
"Well, Mr. Carpetbagger. We got somethin' in this territory called the Missouri boat ride."   Josey Wales

"It's Baltimore, gentlemen. The gods will not save you." Ervin Burrell

CB750 K3 crat | (2) 1986 VFR750F

Offline gravano

  • Full Member
  • *
  • Posts: 71
Re: NGK Plug Wars: D7EA vs. D8EA
« Reply #18 on: April 20, 2010, 07:53:18 AM »
Dar!
Logged

Offline Big Bob

  • Hot Shot
  • ***
  • Posts: 291
Re: NGK Plug Wars: D7EA vs. D8EA
« Reply #19 on: April 20, 2010, 08:23:10 AM »
Where in Chicago are you?
Logged
Pages: [1]   Go Up
« previous next »