OMC Crossflow v4 115hp Turbojet - RPM Tach Issue

[tmfeaster]

I currently have an active thread about my boat/engine (http://forums.iboats.com/showthread.php?t=489522). This thread details issues for repair after an overheat.

Before the overheat my RPM Tach did not work. Since I am near the end of fixing the engine I just replaced the tach with a brand new one because I had already replace the stator and rectifier/regulator (NEW).

I have tripple checked and the wiring is correct but the new RPM Tach doesn't work either. When I opened it out of the box the tach was at 1100rpm but as soon as I installed it and hooked up the battery, it dropped to zero and has been stuck there since.

Any ideas on what I can check next?? The regulator/rectifier I bought had instructions that said it didn't matter which yellow wire went to the stator yellow & yellow/silver wires. Is that true?

Any help is greatly apprecaited. Outside of one muffler gasket this is the only thing left on my boat that doesn't function. Of course, new upholstery is next

 

[tmfeaster]

Re: OMC Crossflow v4 115hp Turbojet - RPM Tach Issue

bump

 

[AlTn]

Re: OMC Crossflow v4 115hp Turbojet - RPM Tach Issue

no direct experience with a tach...from readings here I understand that the tach has <?> a selector for different numbers of poles and the number of poles seems to be half the number of charge coils on the stator?....someone will come along and give a better explanation < or correct this one >...

 

[tmfeaster]

Re: OMC Crossflow v4 115hp Turbojet - RPM Tach Issue

I did notice that switch on the back of it. I will play with that, I thought it was based on the number of cylinders.

 

[boobie]

Re: OMC Crossflow v4 115hp Turbojet - RPM Tach Issue

Set the switch on the back of the tach to position # 6. If it still doesn't work check the gray coming from the reg/rect to the tach.

 

[tmfeaster]

Re: OMC Crossflow v4 115hp Turbojet - RPM Tach Issue

Set the switch on the back of the tach to position # 6. If it still doesn't work check the gray coming from the reg/rect to the tach.

How shal I check the wire? I know it is connected... but obviously something is wrong because I put it in position #6 with no luck.

 

[boobie]

Re: OMC Crossflow v4 115hp Turbojet - RPM Tach Issue

The gray wire starts at the reg/rect and goes all the way to the tach. Do you have a B+ wire going to the tach from the ignition switch to power it up?

 

[tmfeaster]

Re: OMC Crossflow v4 115hp Turbojet - RPM Tach Issue

The gray wire starts at the reg/rect and goes all the way to the tach. Do you have a B+ wire going to the tach from the ignition switch to power it up?

Yes, all wires are intact. I found the problem though. The wires coming from the stator to regulator were rubbed raw by the flywheel. I am replacing it and ensure the wires are clamped down for clearance under the flywheel.