How many poles?

[SimonStDavids]

I have an old yam built mariner forty, one of the two cylinder variety and I can't seem to find out how many poles it has?

The reason that I ask is that I am starting to put the boat back together now, so I hooked up all my new wiring and my tachometer and started her up.

With the help that I received on a previous thread the kill switch and choke worked and the tachometer seemed to work, but when I reved the engine (in neutral and on muffs) so not much the tachometer would advance and then drop back?

Hence I thought maybe I had it set on wrong number if poles?

[Nos4r2]

If you're holding the revs steady and the revcounter is dropping, there's a problem with your revcounter. If you get the number of poles wrong it'll still work,but it'll read either slow or fast.


It is connected up to the right place in the outboard isn't it?

[SimonStDavids]

I think so, it is connected to the green wire.

I think i might need to test it on the water and see what it does when I can open the throttle

I just thought it didn't look quite right? Could it be the timing? I am sure someone told me when you first apply revs, the timing advances. Could it be this that I am seeing on the counter?

[Nos4r2]

Originally Posted by SimonStDavids

Could it be the timing? I am sure someone told me when you first apply revs, the timing advances. Could it be this that I am seeing on the counter?

The timing does advance, but no, that's not what you're seeing.Your revcounter reading isn't linked to your timing.

[SimonStDavids]

Hmmmm

I have just found this on the net: "Some Mariner/Mercury 30 & 40 HP (2 cylinder) non-USA built engines may require a Module (Mercury P/N 17461A2) when using any of these tachs"

That part number isn't yeilding anything on the net though....

[Nos4r2]

I've never come across one of them-but the tach system is fairly simple-all it does is count the number of pulses from the alternator.

Have you got an electric start or a battery charging system and what make is the tach?

[SimonStDavids]

Well the engine is pretty old but it does have electric start so I think it must have an alternator, the tach is a quiksilver one.

[SimonStDavids]

I think my engine my have a magneto ignition and maybe a lighting coil the more research i do, is this substantially different from an alternator?

[m chappelow]

Originally Posted by SimonStDavids

I think my engine my have a magneto ignition and maybe a lighting coil the more research i do, is this substantially different from an alternator?

There's usually 1 coil for each cylinder plus a lighting or generator coil for charging a battery .
So if its a 2 cylinder there will be 3 in total .

An alternator will produce much more power output than a simple lighting coil .
One advantage with a lighting coil though is it will charge up a completely flat battery unlike most Alternators that need a bit of power or a certain amount in the battery before it will start to charge up proper .

Usually if the engine has an electric starter & its powered by a lighting coil there will be a rectifier to change it from Ac into Dc for charging a battery .

[Nos4r2]

Sorry, meant to reply earlier.

Turbodiesel would be your man here-he'll remember/know what it's got under the flywheel. Got a serial number and model number?

I strongly suspect it's an alternator though- a lighting coil isnt enough to recharge a battery with an electric start. You should have 2 wires coming out from under the flywheel that are connected to a rectifier. One of those should also be connected to the revcounter.

[Poly]

My Faria manual says:

40 HP(serial # 582399 and before) --- 4poles
40 HP (after serial # 582399) --- 12 poles

[SimonStDavids]

Originally Posted by Nos4r2

Sorry, meant to reply earlier.

Turbodiesel would be your man here-he'll remember/know what it's got under the flywheel. Got a serial number and model number?
.

This is the serial number 6E9 L 407462, to be honest Have been struggling for a long time to pin down the engines age, the Mariner searial numbers don't seem to make much sence to me

I think it might be the 40C model without autoblend from around 1983 or 1984 but i stand to be corrected.

As per wires coming out from under the flywheel, the are two sets, one wrapped up in blue and one wrapped in black.

One set has what looks like two green wires in it and the other (from memory) has three, brown, red and black.

[Nos4r2]

ok, the 2 green are your charging wires. If your tacho is wired to one of those, it's correct.

[SimonStDavids]

I am pretty sure it connects to one of these green wires somewhere along the line, I will try and trace it back. Should the tachometer connect before or after the rectifier?

[SimonStDavids]

Been doing some more internet digging and came across this:

"These japanese mariners are made by yamaha. I have a 40EL 6E9- model 2 carb. I had trouble with my tach also I successfully fix this problem. first of all this stator is just a little lighting coil but flywheel has 4 magnets make 4 pulses. set any teleflex tach to 2p setting and place a .33 microfarad capacitor across the signal and ground terminal. I pulled apart a mercury adaptor and this is all it was, a .33uF capacitor. the capacitor stabilizes the pulse signal by filtering out induced noise from ignition system to ground."

Does that make any sence to anyone with more brains than me

It might tie up with the additional part number mentioned on some websites?

[Dirk Diggler]

Originally Posted by SimonStDavids

Hmmmm

I have just found this on the net: "Some Mariner/Mercury 30 & 40 HP (2 cylinder) non-USA built engines may require a Module (Mercury P/N 17461A2) when using any of these tachs"

That part number isn't yeilding anything on the net though....

Here's the module