How many poles?

[Turn4fun]

1973 70 hp evinrude. Want to hook up tach, how many poles is this motor?

 

[Joe Reeves]

Re: How many poles?

The tachometer operates off of the charging system pulses, not the poles. The Evinrude and Johnson charging systems emit six (6) pulses. You need a tachometer that can be set to six (6) pulses, usually via a dial on the back of the tachometer.

 

[bktheking]

Re: How many poles?

Pretty sure 70 and greater were 12 pole, 6 pulse.

 

[Turn4fun]

Re: How many poles?

Thank you. I understand the difference between pulses and poles, and I know some tachs have settings for pulses whereas others have settings for number of poles. There is a tach on my boat that says is for J&E applications and the settings are for number of poles. I got the boat without a motor so I have no idea what was originally on it. It is set on 12 ploe so I guess I'm good to go as is.

 

[carbineone]

Re: How many poles?

I would like to know this for sure too.The problem is I have read and have been told here that the 70HP and under 2 cylinders are 5p..I have read here for hours and did not find a definite answer.Mine is a 1974 50HP Lark 2 cylinder...

 

[R.Johnson]

Re: How many poles?

You can count the winding's on the stator ring. If it has 12 winding's, that is 12 pole's or 6 pulse.

 

[carbineone]

Re: How many poles?

I have 4 yellow windings on each side and then there is one directly in the front of the stator and the rear that are maybe black but look differant than the side yellow ones.Sorry they are blue windings not yellow.No differance I am sure but.....Thanks

 

[Joe Reeves]

Re: How many poles?

The "Black" coils petain to the ignition system. The other coils pertain to the charging system.

 

[carbineone]

Re: How many poles?

Well my 74 50HP sure is not a 4p then?Thought you divided the number by 2 and that told you what to set the tach settting at.I am so confused,some people say the older Evinrudes under 70 HP and a two cylinders are 5p and only 3 cylinders are 6p..I do not for sure only what I read and some say my engine is 5p some 6p..Wish someone would come along with the identical motor I have and let me know how theirs works.Joe I have read several of your past posts on this also and am still confused.Need my tach to read perfect for selecting a possible prop size.....Thanks

 

[carbineone]

Re: How many poles?

Well heres the deal/I am having trouble with my teleflex tach working correctly still on my 1974 50HP lark.I have a 85HP older Evinrude also and I counted the blue widings under the 85 and sure enough there are 6 on each side under the flywheel so its a 12 Pole for sure as even the tach in the boat is marked 12 pole on the back..Now everybody has been telling me that my 50HP is either a 12 pole or a 10 pole and I believe neither is true.I have 8 blue windings total so my tach I believe has to be set to the 4p setting on the back anmd my motor is a 8 pole..I cannot believe there can be this much confusion on a simple subject.If it is as simple as counting the poles then why cannot someone just say so instead of guessing..I may sound like I am getting a little angry but it is more just venting my frustration that no one here or any Evinrude dealers I have called cannot tell me a definite answer nor can the new owners of the Teleflex gauge division..I have been told set it to 6p and it reads low.I was then told 5p and it does not hardly work at all.4p setting so far appears to be the best but cannot verify it without some other outside meusuring tool to see if its reading correct...If the original poster would let me know if he thinks his is accurrate and how many poles he has under his flywheel I would appreciate it..I doubt very much he has a 12 pole on his older motor either being a 70HP,possibly if its a 3 cylinder maybe but even then I doubt it...Thanks

 

[F_R]

Re: How many poles?

There is more to it than simply counting the coils. The number of magnets in the flywheel also enter into the equation. EDIT: There also are single phase and three phase alternators. I don't profess to fully understand how it all comes together to make x-number of pulses.

This from the OMC catalog: Sez your 1974 50hp is a 6 pulse

 

[carbineone]

Re: How many poles?

Thanks,I have also seen charts that say any in my year range under 70HP and a two cylinder are 5 pulse also...The question must just be one that cannot be answered 100% I believe..Maybe they used differant pulses on differant models of the same year.My model number is 50473 and its a Lark model..Thats why this is getting so frustrating...Some are sure my motor is 12 pole,some are sure its 10 pole..I can add that my rectifier has 3 wires coming out of it and some say that means 12 pole system some say it does not neccesarily mean that.

I guess it may not be a answerable question unless a guy found a old enough mechanic to have worked on this exact model and year and has installed a million tachs on them so its burned in his mind so well he has nightmares about it,LOL Thanks

 

[carbineone]

Re: How many poles?

Wanted to add this.I am sure it means nothing but am going to put it up anyway.If I leave the throttle set at one setting and run it on 6p setting it shows 3000RPMs,if I set it at 5p it shows 3400RPMs,if I set it at 4p setting it jumps way up to 4200RPMs.Like I say it probably means nothing other than the setting make it read differant RPMs,LOL Is there a way to read the rpms off a old dwell tach meter for cars?doubtful but thats what I need is something to verify the RPMs for sure versus the gauge...

 

[Joe Reeves]

Re: How many poles?

Just to refresh my memory, I just now went thru the OMC factory service manual and read thru its entirety. There is no mention of the word "pole" pertaining to the charging system or any other component (Cover to cover). I started out in this line of work when all there was, pertaining to the Evinrude and Johnson outboards, was a magneto and a manual shift system..... and as the years went by, it was a simply matter for me to learn the new technology as it came into existence.

There are two tachometer setups if I remember correctly..... one operating off of the ignition system (Tiny Tach comes to mind), and one operating off of the charging system (Any tach that functions with the 6 pulse charging system). These tachs have a dial on the back of them which when set to #6 registers the true engine rpm. Setting it to any other number cause the tachometer to register a false reading as does the "pole" tachometer in the above posts.

All of the Evinrude and Johnson engines (with a few smaller hp exceptions) operate the tachometers with the six (6) pulse setup.

Since nobody here (including me) can come up with the proper pole setting, perhaps a phone call or email to the company manufacturing that pole tachometer could solve the problem.

Personally, if it were me, I'd sell that pole tachometer on eBay or elsewhere and purchase the proper six (6) pulse tachometer and be done with it.