While there are many methods and gauges that will work, here are the parts that I used to install oil pressure and water temperature gauges on a YM1700.
Water Temperature Gauge: Sunpro CP8207. Requires metric adapter (16mm x 1.5mm), which is included in Sunpro kit CP7574.
Oil Pressure Gauge: Used Sunpro oil pressure gauge. Requires 1/8-28 (BSP) to 1/8-27 (NPT) adapter, which was included with the gauge kit. This adapter is also included with Sunpro kit CP7573.
If you decide to install a "T" fitting for the oil pressure gauge, you will need a 1/8" NPT "T" fitting, 1"x1/8 NPT close nipple, and a new Oil Pressure Switch with 1/8" NPT threads. I used a Sorenson OPS7, 3-9 psi, available at Advance Auto.
I chose to install the gauges under the dash primarily because it was easy. While most of these parts were available at Advance Auto, I did have to order the metric adapters online at
www.sunpro.com. However, I have since seen the metric adapters at various auto parts stores.
Will post pictures tonight.