Installing Tach

I have a 2002 Yamaha T50 four stroke. I wish to put a tach on it but have a problem. It has two coil packs and either give me 1/2 my rpms. I can find no common link to pick up total rpms. Supposedly there is a wire within the console for this but I can't find it. Any one know how I can install this correctly? Thanks

Re: Installing Tach

Is it the digital or analogue?<br /><br />I have a old version of the owners manuall for my yam 90 2-stroke. It describes how to change the setting of the Tach.<br /><br />I recently bought a new (used) set of instruments. They came from a F50, 2002. I follow the direction and it worked so I guess it will work for you as well.<br /><br />On the back of the tach there is a setting device.<br />On the digital one there is cap that has to be romeved to get to a set of switches. The left one isn't used. The right one swithes between 6 and 12 pole. (up is 6 pole, down is 12 pole, 80-90 hp and V4/V6 engines are 12 pole)<br /><br />On the analoue there is cap hiding a dial selector. Set the dial to 12, 6 or 4 pole (12 poles are 80-90 hp and V4/V6 engines, 6 pole are 40-70 hp, 4 pole is 40Q-55B)<br /><br />Hope this helps...

Re: Installing Tach

It is an after market analog and I have swithced it to 4 cyl. Still only 1//2 reading of rpm's due to picking up from only one coil pack.

Re: Installing Tach

OK, I don't know exactly how and were the Original tach is pickingup its signal. What I understand it gets the signal from the control box and the control box have like a 10-connection harness going back to the engine.<br /><br />The original tach connects to the yellow, black, and green from the control box. Black is earth/minus, yellow is +12v controlled by the starting key, the green I don't no know so I guess its for Tach input.<br /><br />You do have the original controlbox?

Re: Installing Tach

sounds like an automotive style tach and will never work on your engine. you need to insure your using an a/c type tach that is ment to be altenator driven. the yamaha digital works well. it also contains the visual indicate for the alarm system as well as a trim gauge if ya have trim. the tach should be set on the 12 pole or 6 pulse setting for the 02 F and T 50 HP.

Re: Installing Tach

OK, thanks guys. It is an automotive tach. I do have the original control box so I might be able to find the wires you mention. I would like to find a used set of gauges but they are hard to find and new ones are very pricey. I do have trim gauge so perhaps if I follow this wire I will find more. Thanks a million.