Author Topic: Where to get spark plug caps? (Read 20233 times)

andy8190 · « **on:** July 21, 2009, 01:41:35 PM »

So i want to place my spark plug wires and caps on my 74 cb550 and I know the stock resistance for the caps are 10k but I have looked and I can not find any NGK spark plug caps that are 10k, I can only find 5k. Does anyone know where 10k aftermarkets can be purchased?

TwoTired · « **Reply #1 on:** July 21, 2009, 04:10:16 PM »

Well, doesn't the Honda dealer still sell them?

For education go here:
http://www.ngk-sparkplugs.jp/english/techinfo/resistor-wire/03/index.html

I think the 550 uses two - XD10F (inner cyls) and two- VD10F (Outer Cyls).

Anybody who stocks NGK plug caps should either have them or be able to order them from NGK.

NGK certainly still makes them. I guess that lots of places are just minimizing their stock on shelves.

B.O.X.N.I.F.E. · « **Reply #2 on:** July 21, 2009, 04:37:01 PM »

I've been looking, I don't think NGK has any 10k's left in the US market.

WHALEMAN · « **Reply #3 on:** July 21, 2009, 04:59:09 PM »

I have got them cheapest at www.denniskirk.com Dan

punch455 · « **Reply #4 on:** July 21, 2009, 05:33:36 PM »

Partsnmore.com carries them. Not sure about availability though..

Popwood · « **Reply #5 on:** July 21, 2009, 06:19:52 PM »

Geez, could I be that lucky? Just replaced mine a few weeks ago. Picked them up from my neighborhood cycle shop. Didn't even have to go the Honda dealer.

andy8190 · « **Reply #6 on:** July 21, 2009, 07:13:59 PM »

i went by 2 cycle shops in town today an neither had a 10k resistor, they were all 5k. I am still searching online stores

andy8190 · « **Reply #7 on:** July 21, 2009, 07:17:51 PM »

also just searched dennis kirk and partsnmore and if you get them there you can get 5k but not 10k so ex that site as well

B.O.X.N.I.F.E. · « **Reply #8 on:** July 21, 2009, 08:08:35 PM »

It's looking like OEM is the way we'll have to go. NGK has one 10K left that I found, but it's a short 90 degree boot, will not fit #2 & 3.

andy8190 · « **Reply #9 on:** July 21, 2009, 08:27:26 PM »

yeah i think you are right but I am wondering, any 550 guys out there that have used the 5k resistors and can tell us if they do work?
Any draw backs to using the 5k rather than the 10k for the 550?

If we buy oem through honda is it the old school plug caps or do you think they went aftermarket now?

Gordon · « **Reply #10 on:** July 21, 2009, 09:58:11 PM »

Aren't NGK caps OEM for our bikes?

andy8190 · « **Reply #11 on:** July 21, 2009, 10:38:48 PM »

Yeah NGK are the OEM but the NGK current ones are plastic and the originals are rubber, that is what i meant. I would kind of like to have the plastic type

TwoTired · « **Reply #12 on:** July 21, 2009, 10:40:41 PM »

The original caps were plastic with rubber seals/gaskets on each end.

andy8190 · « **Reply #13 on:** July 21, 2009, 10:44:03 PM »

oh my mistake. I like the look of the newer ones. TwoTired could you tell us what running 5k would do, if any negatives?

Caymen · « **Reply #14 on:** July 21, 2009, 11:27:50 PM »

Correct me if I am wrong because I am trying to learn about motorcycles, but does the 10K resistance vs. the 5K resistance make THAT much of a difference?

Is this something we could feel of is this something that plays on our minds?

Tom

TwoTired · « **Reply #15 on:** July 21, 2009, 11:54:00 PM »

Quote from: andy8190 on July 21, 2009, 10:44:03 PM

oh my mistake. I like the look of the newer ones. TwoTired could you tell us what running 5k would do, if any negatives?

I'm not exactly certain if most would notice a difference.

The resistance comes into play during the spark event, it limits the spark current, reduces the event rise initial overshoot, delaying the rise time of the spark (in very small time increments), and spreads the spark energy over a longer time event, thereby extending the spark duration.

It is possible that the 10K resistance was selected to help reduce coil power consumption, by not allowing the coils to completely discharge before the next spark event. ...in theory. I've not checked the coil discharge time vs dwell interval.

I've not measured any differences and I don't have any 550s that are using 5K caps. The engine ought to run with either. Perhaps fractionally better with 10K and maybe with less draw on the charging system. But, aside from the theory which I believe is sound, I'm just spit-balling, here.

Gordon · « **Reply #16 on:** July 21, 2009, 11:56:36 PM »

Quote from: Caymen on July 21, 2009, 11:27:50 PM

Correct me if I am wrong because I am trying to learn about motorcycles, but does the 10K resistance vs. the 5K resistance make THAT much of a difference?

I seriously doubt it. I've been running 5ohm caps on my 550 for four years now. Perhaps it's having some kind of negative effect, but if it is it's not something I'm aware of. I'm sure there are plenty of others here running the same caps on their 550's without any noticeable issues, too.

andy8190 · « **Reply #17 on:** July 22, 2009, 12:02:52 AM »

can you believe out of the 2 bike shops i went to today, neither had spark plug wire in stock. Thats the kind of hassle i have to deal with around here haha

TwoTired · « **Reply #18 on:** July 22, 2009, 12:07:59 AM »

I'd sure like to know (for sure) why Honda thought the difference was significant enough to make the 550s use 10K caps. Most of their engineering is pretty thorough and not based on whimsy.

Certainly, if I couldn't get 10K caps, I'd use the 5K...at least until I could find the 10K ones.

andy8190 · « **Reply #19 on:** July 22, 2009, 12:18:21 AM »

You think Hondaman might know the answer to that one?

Deltarider · « **Reply #20 on:** July 22, 2009, 12:30:04 AM »

Quote

You think Hondaman might know the answer to that one?

He does have the scope to check for differences if any...

Pinhead · « **Reply #21 on:** July 22, 2009, 02:24:01 AM »

For what it's worth, the '79 CB650 runs 5k resistors.

B.O.X.N.I.F.E. · « **Reply #22 on:** July 22, 2009, 12:22:29 PM »

I'm running the 5K right now on my 550.

The dumbest engineer working for Honda would probably still make me look like a caveman. Unless I can find aftermarket 10k NGK's (they do look cool!) I'm going back to OEM boots.

Gordon · « **Reply #23 on:** July 22, 2009, 12:33:11 PM »

Quote from: boxnife on July 22, 2009, 12:22:29 PM

Unless I can find aftermarket 10k NGK's (they do look cool!) I'm going back to OEM boots.

I thought we already established that NGK plug caps are the OEM caps. $:-\$

andy8190 · « **Reply #24 on:** July 22, 2009, 01:00:22 PM »

i think what he means when he says oem is the caps with the old style plain black look instead of the new all shiny plastic looking ones. thats what i mean when i say oem as well

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Author Topic: Where to get spark plug caps? (Read 20233 times)

WHALEMAN