New guy with a few questions

[willy1094]

Hello,
I just purchased a pontoon with a yamaha c40 outboard. I would like to add a tachometer and have read that there should be leads coming from the control box that I can just plug into. I purchased a downloadable copy of the yamaha service manual hoping the electrical diagram would help but it is not real clear (at least not to me). My motor is a 1993. Can anyone help me out with this?

My second question is about the oil/fuel mix. The service manual says 100:1 but they guy I bought it off of said that the marina he purchased it from told him to run 40:1. I've read on here that some are concerned with running too thin on oil even when it is recommended to run thin. Any input on this? My last question or concern is that the manual I got I purchased based on the part number lit-18616-00-45 but when I got it the model number shows CV40E. Does the "V" mean that this manual is not a match to my outboard? From what I'm finding online I'm ok but want to make sure.

Thanks in advance for any help!

[99yam40]

On my Xpess with a C40TLRX there was a set of wires coming out of the controls with a red, yellow,green, and black.
Yellow is key on power
Green is signal to tach
Black is ground (neg)

I run 50/1

[robert graham]

100:1 oil ratio will lubricate the motor while it's running, but 50:1 will lubricate the motor AND provide some oil film corrosion protection for crank, bearings,etc. when motor is turned off. I use 50:1 and believe it's pretty well accepted by most folks. The Pennzoil 100% Synthetic Outboard Oil at 50:1 is good and seems to reduce smoke and carbon. Good Luck!

[willy1094]

Thanks a lot!