Evinrude E-NATION, for those dedicated to water, power, fishing and fun
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Skipper
Posts: 12
Registered: ‎03-15-2019

Indexing spark plugs?!

I'm a recent new owner of a 2007 90 HP ETEC and as part of spring maintenance I decided to change the plugs. I've done this many times on cars I've owned, so it seemed like an easy first project. Per specs in the service manual I ordered three of the prescribed Champion plugs (at $10 a pop from Amazon). Following the manual's instructions, I marked the ceramic on each plug to match the open side of the ground electrode before screwing the plug into its receptacle. For those who haven't done this before, the manual then has a diagram with a circle drawn around the spark plug's position on the engine. The right half of the circle is shaded and the left half is not. Instructions say to tighten to 15 foot pounds with a torque wrench, and if the line falls within the unshaded half, you're good to go. If not, you're supposed to tighten to 30 foot pounds, and if the line ends up in the unshaded half, you're good. If it remains in the shaded half, "the spark plug cannot be indexed for that cylinder. Try another spark plug and repeat the steps above."

WHAT? That sounds innocent enough at first, but after 3 hours of mixing and matching and retrying (numerous times) my three plugs in the various three receptacles, two ended up borderline into the unshaded area and the third is a "no way, nohow, I'm staying smack in the middle of the shaded area." I thought rotating the plug to start from a different orientation would solve this, but no, I always got the same result.

So do I REALLY have to chuck this $10 sparkplug and keep trying more until one just happens to match up with the right threads?

And what about the other two that are on the borderline? How crucial is this? I've never encountered this sort of nonsense in other machinery.

Thanks if you have any tips or workarounds.

Captain
Posts: 218
Registered: ‎09-07-2018

Re: Indexing spark plugs?!

You have probably seen this, but fwiw...

 

https://www.youtube.com/watch?v=p68apieFgIA

 

I will be interested in hearing from the pros on this, but my understanding is that those plugs that don't line up properly can't be used (if you want maximum performance).  Maybe that's the beauty of Amazon, order twice as many as you need, check which ones work and send the others back Smiley Wink

Captain
Posts: 30
Registered: ‎07-24-2012

Re: Indexing spark plugs?!

I find that there is always a couple that will not index. I always order a couple extra just for that reason. Sometimes I will get them to index in a different engine / cylinder. I change my plugs every year. I am usually able to find reasonable pricing and our deals on plugs. A year ago champion had a rebate that had them around 5 each.
Admiral
Posts: 8,406
Registered: ‎07-14-2011

Re: Indexing spark plugs?!

 

 

With a V4 or a V6 Evinrude E-TEC it is easy to use a plug in the opposite bank if it does not index initially. On an inline 2 or 3-cylinder motor you have to try a different sparkplug. There is no way around it. Often dealers will exchange plugs if needed or several E-TEC owners may swap plugs if need be.

The factory specification is just over 180° for the allowed plug gap location to minimize needing to try a different sparkplug.

 

 

 


"There is never just one thing wrong with a boat";
                    -- Travis McGee, main character in a book series by John D. McDonald 


 



***************

The factory recommends that a properly trained technician service your Johnson or Evinrude outboard motor. Should you elect to perform repairs yourself, use caution, common sense, and observe safety procedures in the vicinity of flammable liquids, around moving parts, near high-temperature components, and working with electrical or ignition systems.

The information offered here is only general in nature and should not be construed as complete factory approved procedures, techniques, or specifications. Always use the proper service manual for your motor, up-to-date service literature, the correct tools, and have an understanding of how to proceed with troubleshooting and repair methods. If you are unsure or uncomfortable with a procedure, a situation, or a technique, enlist the services of a factory trained technician.


Skipper
Posts: 12
Registered: ‎03-15-2019

Re: Indexing spark plugs?!

Thanks for the responses. I've already ordered more spark plugs.Seems like a ridiculously bad design issue.

Unfortunately  I don't think Amazon will take back the plugs I've already marked with a sharpie for the indexing.

Skipper
Posts: 12
Registered: ‎03-15-2019

Re: Indexing spark plugs?!

"The factory specification is just over 180° for the allowed plug gap location to minimize needing to try a different sparkplug."

 

So, just to clarify, Bluewater Bill: Are you saying that it's OK to be on the line or just slightly into the shaded area?

Admiral
Posts: 8,406
Registered: ‎07-14-2011

Re: Indexing spark plugs?!

Yes to being on the line. Look closely at the accepted range of the sparkplug gap positioning.

 

 

 


"There is never just one thing wrong with a boat";
                    -- Travis McGee, main character in a book series by John D. McDonald 


 



***************

The factory recommends that a properly trained technician service your Johnson or Evinrude outboard motor. Should you elect to perform repairs yourself, use caution, common sense, and observe safety procedures in the vicinity of flammable liquids, around moving parts, near high-temperature components, and working with electrical or ignition systems.

The information offered here is only general in nature and should not be construed as complete factory approved procedures, techniques, or specifications. Always use the proper service manual for your motor, up-to-date service literature, the correct tools, and have an understanding of how to proceed with troubleshooting and repair methods. If you are unsure or uncomfortable with a procedure, a situation, or a technique, enlist the services of a factory trained technician.


Captain
Posts: 599
Registered: ‎08-20-2017

Re: Indexing spark plugs?!

To meet emission standards and get the designed fuel efficiency, the open end of the plug electrode should be towards the injector or 90 degrees either side if it. Having the back side if the plug electrode blocking the fuel spray from the injector will result in all the fuel not being burned. Indexing a plug a little outside of the 180 degree range will have no noticable effect on engine performance.
As a dealer tech we just try another plug out of stock if they index too far off.
As for the post about changing plugs every year. It can't hurt but we find that most of our customers get a 300 - 500 hour life out of their spark plugs.
Captain
Posts: 32
Registered: ‎07-13-2018

Re: Indexing spark plugs?!

What happens is...after u torque it the washer comprsses and u don't have that exptra give.

These are your best friends

https://www.amazon.com/Moroso-71910-Spark-Indexing-Washers/dp/B000COS7AO/ref=sr_1_3?hvadid=241935295...

 

 

Admiral
Posts: 8,406
Registered: ‎07-14-2011

Re: Indexing spark plugs?!

 

 

Do not ever use indexing washers in an Evinrude outboard. Plug height positioning is paramount for proper running due to the fuel spray cone coming off the injector and deflector pin.  This is not an automotive engine.

 

 

 


"There is never just one thing wrong with a boat";
                    -- Travis McGee, main character in a book series by John D. McDonald 


 



***************

The factory recommends that a properly trained technician service your Johnson or Evinrude outboard motor. Should you elect to perform repairs yourself, use caution, common sense, and observe safety procedures in the vicinity of flammable liquids, around moving parts, near high-temperature components, and working with electrical or ignition systems.

The information offered here is only general in nature and should not be construed as complete factory approved procedures, techniques, or specifications. Always use the proper service manual for your motor, up-to-date service literature, the correct tools, and have an understanding of how to proceed with troubleshooting and repair methods. If you are unsure or uncomfortable with a procedure, a situation, or a technique, enlist the services of a factory trained technician.