Yamaha engine mount bolt layout

[dcobbett]

I’d like to layout and drill the holes in the boat's transom to mount a 2003, 130TXRB Yamaha, but the dimensions in the Yamaha Service manual I have show a two-tenths of an inch difference in the center to center spacing for the horizontal top and bottom sets of holes, and I can’t figure out what set of dimensions apply to my engine. The drawing and dimensional chart in the manual shows the dimensions as 12.8" and 9.8" for a saltwater series motor (which mine is not), and 13.0" and 10.0" for a counter rotating motor (which mine is not).

I did a search on a few sites and found a thread that said the standard Yamaha bolt pattern was 12.8" for the top holes and 9.8" for the bottom ones.

Doesn't make sense to me that Yamaha would have different dimensions for saltwater series vs standard motors, let alone left vs. right hand motors, but, just in case, does anyone know what dimensions I should use?

[Fishjack]

I removed my Johnson 225 and replace it with my current Yamaha 250 and the holes matched fine.. I found this online for what it is worth -

"It is believed that the hole arrangement currently in use by most engine manufacturers follows these dimensions:

The top pair of holes are spaced 12 and 7/8-inch on center; each hole is 6 and 7/16-inch from the engine bracket centerline.
The bottom pair of holes are spaced 9 and 7/8-inch on center; each hole is 4 and 15/16-inch from the engine bracket centerline.
The spacing between the top and bottom pair of holes is 8-inches on center.
The centerline of the top holes is 2-inches below the top of the engine bracket. The holes in the transom should be 1 and 7/8-inch below the top of the transom. In no case should they be closer than 1 and 3/4-inch to the top of the transom. Holes located 1-7/8-inch below the top of the transom will produce a slight gap between the transom and the engine mounting bracket. This gap can be filled with an appropriate spacer or shim to help bear the engine's weight onto the transom.
When locating holes on the transom, do not assume the top of the transom is a straight or true edge. Determine the transom vertical centerline by measuring equal distances from the hull's chines. Align the engine mounting holes to the true vertical centerline of the transom, not to the top edge of the transom."

Hope that helps a little..
Jack

[Fr. Frank]

The bolt holes for all major OB motors 88 hp & higher, post 1987 is a BIA standard. Most of the mfg were using the standard before that, except Mercury/Mariner and Nissan/Tohatsu on their 90 - 140 hp models. But even those two got on board after 1987.

BTW, the standard adopted was the EverRude V6 pattern used from the late 70's on.

You can probably borrow a metal drilling template from a local dealer to drill the holes, makes it much easier.

[dcobbett]

FishJack,

Thanks. That's the post I found. The information is pretty straight forward, and it's probably correct for the motor I have.