The following are step by step photos of my installation of the Tiny Tach Commercial tachometer on my Vespa LX 150. These instructions are for informational use only. If you break something, don't blame me.

Here is a gallery of the images in various sizes, in case you want to see the original huge (2.5 MB) image.

Here's the product:

I was going to install the tachometer inside the gloce box, but after removing the front cowl lining, I decided there wasn't a good spot to put it. I also figured that the majority of the time I want to use the tach will be while working on the engine, so having it near the engine area would be a better choice. Working range is only -10F to 140F, so I didn't want it inside the engine bay. I decided to mount the tachometer on the plastic cover beside the battery.

Here is a before photo:

Remove the gas cap, the battery cover, and the 5 phillips screws holding on the plastic shroud.

Don't forget to slide off the fuse box from the battery area. Just pull it straight up. Put the gas cap back on when you're done.

Here's what it looks like underneath the cover. The extra wires on the battery and the small connector sticking out of the right-hand hole in the back wall of the engine bay is the pigtail for the Battery Tender Jr.

Lightly clamp the tachometer in the desired position. Make sure to center it between the two slots where the battery cover go. You can see this better in later photos.

Then drill the two mounting holes. I used a special self-centering countersink drill, but using a drill that is the same size as the holes in the Tiny Tach will do the same thing.

I then marked and drilled holes for the wires. The gray power wire can fit though the drilled hole, but the ground and pickup wire hole has to be slit for installation. Here I'm using a coping saw to slot the appropriate hole. See how they are centered between the slots for the battery cover tabs? Make sure to do the same.

Next, cut off the ribs on the underside that might interfere with the washers and nuts. Also deburr the holes with a chamfering tool like the orange handled tool or a larger drill bit.

Here's a top view of the tach mounted on the shroud.

And one from the bottom.

Test fit!

I crimped some ring terminals on the ends of the power wires and attached them to the battery terminals.

Next, I fed the ground and pickup wire through the grommet and clamped it in with the wiring loom of the scooter. I wrapped the red pickup wire around the sparkplug wire 4 times as instructed. This was easiest to do by removing the cover on the front of the body, behind the floorboard.

I then ran the ground back up into the engine bay and mounted it to a convenient bolt, being sure to scrape away some paint for a good ground.

Then I started putting things back together. I bundled any spare wire and tied it with a zip tie, and screwed the plastic shroud back on. Note that there is a tab that need to go under the rear edge, behind the seat latch. Be sure to get it in place. Don't forget to slide the fuse box back in place in the battery area.

All done! (Yes, I know it is slightly crooked. I'll open up the mounting holes a bit and straighten it up when I replace the fasteners I had laying around with some stainless steel fasteners.)

Start 'er up and make sure what mode to put it in. I left it in the default single mode, as the idle RPM is supposed to be 1600 -1800. Seems I'm a bit high.

If there are any questions or comments, just let me know. I can add more photos or instruction if something isn't clear.
⚠️ Last edited by Steve on Sun, 16 Apr 2006 17:35:40 +0000; edited 1 time