Help wiring trim/oil harness from older digital multifunction gauge

[wiznut86]

Poles are poles. Two strokes fire twice as often as four strokes. Even though they may use the same number of poles.

Tachometers for both two and four strokes have a switch so that it can be changed from one type of motor to a different type of motor. Even it they both have the same number of poles.

Ever heard the saying "you can't get there from here"?

I have never heard of a differentiation between two and four stroke motors for poles, only that you need to have the right number of poles selected for a gauge????? As I understood it, the number of poles is used to basically calculate when the alternator has made one full revolution... 12 pole alternator... counts to 12... = 1 rotation....

Am I way off here???

[boscoe99]

You may be correct. Try it and see.

[99yam40]

smaller 2 strokes had different poles, so they needed the switches even for the different 2 strokes

[Jason2tpa]

There is a member on the THT forum who has mastered refurbishing yam tach and speed gauges. His website is GaugeSaver.com – LCD Gauge Restoration and Repair. Most people throw away their gauge once the polarizing lens and/or plastic front lens is scratched up. He buys these, replaces bad parts with new parts and resurfaces the plastic front lens. Gauge looks brand new.

[wiznut86]

There is a member on the THT forum who has mastered refurbishing yam tach and speed gauges. His website is GaugeSaver.com – LCD Gauge Restoration and Repair. Most people throw away their gauge once the polarizing lens and/or plastic front lens is scratched up. He buys these, replaces bad parts with new parts and resurfaces the plastic front lens. Gauge looks brand new.

Looks like he does good work. I'll definitely look into that next time. I already bought some adhesive polarizing film to refurbish the tach myself.

[Jason2tpa]

Looks like he does good work. I'll definitely look into that next time. I already bought some adhesive polarizing film to refurbish the tach myself.

I refurbished by tach using this THT thread as a guide:
Repair Faded Yamaha Multifuction Gauge - The Hull Truth - Boating and Fishing Forum

It's very detailed and the author of that thread makes himself available via private msg if you come across problems. Very nice guy.

It's fairly easy to complete. The most difficult part for me was cutting off the stay tabs inside the tach. Just like there are 4 tabs on outside of casing, there is 4 tabs securing down the electronic board. These have to be removed in order to access the LCD. I used a razor blade, but if I had an exacto knife it would have been easier. You'll know what I mean once you're at that step. Removing the adhesive on both sides of the LCD glass is the most time consuming. The author of the above thread stated it took him an hour. I soaked the glass in rubbing alcohol for 10min to loosen adhesive, then used towel soaked in Goof Off to rub off what the alcohol failed to loosen. Then used a razor blade and carefully scraped off adhesive. Took about a 1/2 hour for both sides.

Good luck.

[wiznut86]

I have never heard of a differentiation between two and four stroke motors for poles, only that you need to have the right number of poles selected for a gauge????? As I understood it, the number of poles is used to basically calculate when the alternator has made one full revolution... 12 pole alternator... counts to 12... = 1 rotation....

Am I way off here???

Just to report back and wrap this up for others that might come across this thread. The old gauge does read the RPM's correctly, but the hang up comes in the tilt/trim and warning lights. Yamaha switched how they read tilt from 3 wire to two wire. The old gauge reads tilt off of the old 3 wire system and there's no way I found to go from one to the other. I ended up buying a new modern gauge so that I could get a working tilt/trim gauge. If all you want is RPM, the old style gauge WILL work on current 4 strokes and report the correct numbers. The old gauge and my new gauge give the exact same RPM readings.