tachometer

[kwoolard]

I want to install a dash mount tachometer on my 1974, 2 stroke, 40HP, Johnson that was not originally equipped with one. Is there a tach with leads that attach to the terminal board that will read the AC current, or one that attaches to the coil or spark plugs? What type of tach should I be looking for?

 

[dkondelik]

Re: tachometer

Hi Kwoolard,<br /><br />Might try Tiny Tach.<br /><br /> http://www.tinytach.com <br /><br />attaches to 1 spark plug lead. No "pole" to set.<br />Not too fancy but not a bad $$$<br /><br />I'm sure it is not the only one But I've not found another inductive pickup panel mount tach.<br /><br />GoodLuck<br />HAVEFUN!

 

[kwoolard]

Re: tachometer

Tiny Tach seems like a reasonable solution. Since my motor is a 2 stroke, I am going to need the model that reads 2 sparks/rev. TT226NR-1C*<br />Model for twin cylinder engines with a spark firing every 180 degrees of the engine crankshaft. Am I right??<br /><br />Also, is it not possible to hook up a regular dash mount needle tach to this outboard wired up through the coils??<br /><br />Is inductive the only type of tach that is a possible solution??

 

[dkondelik]

Re: tachometer

Hi Again Kwoolard,<br /><br />Sorry, not familiar with your particular motor. Many if not most of even these older boat motors only fire once per cylinder per rev. You might want to confirm this before you select you tach.<br /><br />I would guess that your 40 Hp OMC has two sets of points, one for each cylinder. and thus, fires only once per cylinder per rev. Additionally,I would GUESS that you will find 2 coils under the flywheel. Again, one for each cylinder.<br /><br />Others an this site are VERY familiar with your motor. I'm sure someone can confirm thisin short order.<br /><br />I believe the functional premis for the Tiny Tach is inductive coupling. you don't want to tie the pickup to any hard point(don't tie it to any contact on any coil). You just wrap the pickup lead around ONE of the plug wires.<br /><br />Goos Luck<br />HAVE FUN

 

[rickdb1boat]

Re: tachometer

kwoolard <br />Don't see any reason you can't install a regular tach, as long as your motor has a charging system. Any Tach(ie:Teleflex) will work as long as you can set it to 6 poles. Check out the site below. Is your motor a tiller or remote??<br /><br /> web page

 

[dkondelik]

Re: tachometer

Rickdb1boat,<br /><br />I like your solution. Can you help me to understand one thing? I am confused by the 6-pole thing. I was under the impression that this refered to # of contacts on a distributor. An thus, the suggestion of the Tiny Tach. Obviously ia am with comfusion on this.<br /><br />Thanx<br />(Sorry, maybe this should be a new thread but since we're on the subject,...)

 

[rickdb1boat]

Re: tachometer

kwoolard <br />The setting 6 poles refers to the number of poles on the alternator, not the distributor. Yours would actually have a "10" pole alternator, which means you would set yours for "5" pole on the tach, Not "6" as I thought.

 

[kwoolard]

Re: tachometer

Rickdb1boat,<br /><br />My motor is equipped with a charging system. However it is on the magneto, not an alternator.<br />unless you are considering the magneto an alternator. That being the case will the Teleflex tach still work??<br /><br />I have researched the Tflex tachs and from the wiring diagram it looks as if its leads attach to the terminal posts. The same posts that the rectifier and the charging system attach to. I would assume that the tach would work?????

 

[rickdb1boat]

Re: tachometer

Yes, it will work. and yes, it would attach to the terminal that the rectifier is or to the Gray wire. Do you have a remote control on your boat or is it tiller??<br /><br />EDIT: Only if you have an alternator system, not magneto. Sorry, brain freeze...

 

[V156]

Re: tachometer

If your looking for a good tach at a good prices, go to www.surplusunlimited.com and check it out.<br /><br />Dutch