Indexing plugs

**David** · 04-21-2022, 07:03 AM

It took a while to find some plugs for my 200XS ROS this year. I ordered 12 hoping to find 2 to index properly in the tricky holes.

Q1 Are the 200XS plugs common with the 300XS? NGK 1ZFR7M
Q2 Where do you buy them?
Q3 Could some smart guy develop a series of thin washers to allow any plug to be used in any hole? I don't know how many thousands of an inch would rotate the plug 90 degrees or if the extra thickness would move the plug too far from the piston.

**mistah_max** · 04-21-2022, 07:43 AM

i cant help you with the plug indexing but i can relate to how hard it is to fing affordable plugs in canada...the champion QL77PP plugs used in my 300x cost upward of 30$ each! ridiculous! as of now, best deal seems to be with JEGS but shipping and brokerage fee will surely sour the deal quite a bit..

**David - WI** · 04-21-2022, 08:15 AM

You can buy indexing kits almost anywhere... Jeg's, Summit; J&P Cycle, etc.

https://wahlracing.com/product/spark...exing-washers/

**Chaz** · 04-21-2022, 09:12 AM

Can't help you with the 200 (although you can go on the NGK site and find out what each letter / number stands for)

I won't buy iridiotium .. or anything champion for that matter. That QL77 .. in a standard NGK is a BR8HS . Don't get the BR8HS-10 as that means it has a 1mm gap. The standards are gapped at .030 and run a lot cleaner than the .040's .

At $1.85 each , I usually buy three or five box's at a time. That of course was pre- FJB

Indexing washers are OK, just as long as you don't pull the plug out so far as to expose the first thread of the cylinder head. Having the sharp edge of a thread can turn it into a mini glow-plug and cause more harm than good.

**racer** · 04-21-2022, 09:31 AM

The Q in a champion is a suppressor plug where as the R in NGK is a resistor and a Z would mean suppressor. IMO on many engines wont make much difference but on a OMC engine they need the suppressor plug.

**25two.stroke** · 04-21-2022, 11:28 AM

Originally Posted by David

It took a while to find some plugs for my 200XS ROS this year. I ordered 12 hoping to find 2 to index properly in the tricky holes.

Q1 Are the 200XS plugs common with the 300XS? NGK 1ZFR7M
Q2 Where do you buy them?
Q3 Could some smart guy develop a series of thin washers to allow any plug to be used in any hole? I don't know how many thousands of an inch would rotate the plug 90 degrees or if the extra thickness would move the plug too far from the piston.

Yes 300xs is the same plug as 200xs
They list from mercury at $34 each.
You can get them on ebay right now for 10 somethin a piece. That is a damn good deal and if I was you id order a dozen before that deal is nla.
https://www.ebay.com/itm/37177434261...sAAOSwqGlaqUBP

Indexing kits as mentioned above are available and people use them all the time on those stupid etecs that MUST have their plugs indexed or they foul. What chaz said is critical though...

**David** · 04-21-2022, 01:10 PM

I paid $14.21 on EBay, not quite as good as quoted above, but half of OEM pricing. Maybe Chaz will approve.

How can I tell if an indexing washer is exposing the first thread of the cyl head? Maybe it’s safer just to buy a lot of plugs.

**25two.stroke** · 04-21-2022, 01:16 PM

Originally Posted by David

I paid $14.21 on EBay, not quite as good as quoted above, but half of OEM pricing. Maybe Chaz will approve.

How can I tell if an indexing washer is exposing the first thread of the cyl head? Maybe it’s safer just to buy a lot of plugs.

Pull a head and look and figure how much spacing you can have on any one plug hole and then never exceed that. Or you can always measure the thread depth with a caliper and then the plug and make sure you aren't spacing it out too much. Most heads you can put some thick spacers in there before you expose a thread.

**David - WI** · 04-21-2022, 05:47 PM

If you use just 1 spacer from any of those kits, you won't have to worry... if none of the shims will do then try that plug in a different hole.

**David** · 04-21-2022, 07:36 PM

Thanks all

**Dave Strong** · 04-22-2022, 11:50 AM

I used plug index washers in modified sled motors, can not recall where I got them. my boats I run surface gap so no issue.

Dave

**seansbaja1982** · 05-04-2022, 07:26 PM

What about BUZ8H plugs. Surface gap, resistor plugs. Same as BU8H but resistors. Pro Marine $7.00 each.

**LakeFever** · 05-05-2022, 06:16 AM

I never noticed any difference from plug indexing. What say you Chaz?

**David - WI** · 05-05-2022, 06:28 AM

Originally Posted by David

I paid $14.21 on EBay, not quite as good as quoted above, but half of OEM pricing. Maybe Chaz will approve.

How can I tell if an indexing washer is exposing the first thread of the cyl head? Maybe it’s safer just to buy a lot of plugs.

.

Counterfeit NGK's were a huge problem years ago... I doubt it's gotten better? The fakes were not reliable and not the proper heat range they were marked for. Bad news in a hi-perf motor.

How to identify fake spark plugs | NGK spark plugs

https://www.ngkntk.com/newsroom/blog/emea/fake-or-not/