1975 Merc 115 trigger issue

[Pjohnston]

I'm assuming the piece of metal I'm pointing at with a metal prong in the picture below is the "trigger plate", I'm going to be calling it that anyhow.

The plate is sitting there loosely. It isn't secured properly onto the button or distributor shaft. So when it catches and spins like it should, it fires and then when it just sits there it doesn't. It is spinning. How do I secure it.

 

[Pjohnston]

Is this normal?

I'm assuming the piece of metal I'm pointing at with a metal prong in the picture below is the "trigger disk", I'm going to be calling it that anyhow.

The disk is sitting there loosely. It isn't secured properly onto the button or distributor shaft. So when it catches and spins like it should, it fires and then when it just sits there it doesn't. It is spinning. How do I secure it.

 

[GA_Boater]

Would you post a larger pic? And what Merc or Mariner are asking about?

 

[Pjohnston]

Would you post a larger pic? And what Merc or Mariner are asking about?

It's a 1975 mercury 115. I'll have to post a picture in the morning.

 

[Pjohnston]

[No message]

 

[GA_Boater]

No, not normal.

The rotor disc must be secure on the shaft. The only way to fix it is to remove the one piece shaft and rotor.

Do not attempt to remove the rotor from the shaft, it costs more than 200 bucks. The disc is about $25.

Boatinfo has the an aftermarket manual with a how-to and it isn't very good. Type III Ignition - http://boatinfo.no/lib/mercury/manuals/mercury_1965-1989_40-115.html#/196

 

[Pjohnston]

Yeah but I can wiggle the disk a out an 1/8th of an inch either way. There is also a lot of room up and down. Its almost like the shaft isnt in far enough. Is that possible?

 

[Pjohnston]

Here is a picture of the whole thing

 

[jimmbo]

It is called the 'Timer Plate'. There is supposed to be a tab on the Timing Plate that engages a Slot on the Rotor Shaft. A spacer is then placed over the shaft on the Plate, then the shaft is pressed into a ball bearing, I would assume the spacer against the bearing is what keeps the the plate in place.

You really need to get a Service Manual. preferably one by Mercury, specific to your engine

 

[Faztbullet]

There is a nut and sleeve under the upper bearing that holds this assy in place..sounds like it has backed off.

 

[MatthewtheDruid]

For that to happen the rotor shaft would have to have slid down, but for that to be possible the nut over the top bearing would need to be loose. To get to that to fix you’d need a flywheel puller, preferably a merc service manual, it’s not as complex as it looks but it’s easy to break stuff, rubber mallet is a must. Something that won’t crack the $200 rotor... like I did... I had 2 so it could have been worse. And the one I broke was going bad anyway. That’s what I tell myself so I can sleep at night. Be very careful whatever you end up doing.