Wiring a replacement tacho BF50

Hi I have a Honda BF50 4 stroke that has Faria Instruments wired, including a faulty Faria Euro Tacho. I have just purchased a new Honda Tacho and was wondering if I can use the existing wiring going into the Faria to Connect my new Honda one. The Honda gauge has 4 wires a red?white and a yellow/black fitted with male bullet ends, also two black ones fitted with female bullet ends. The Honda tach has HP-0243-001 on the face.
The Faria has terminals for Battery, signal and earth. Am I right in thinking that I wire the Red/white from the Honda tacho to the Battery wire on the Faria and the Yellow/Black to the existing signal wire on the Faria and the two black wires from the Honda tach to the ground wire from the Faria? Or is it more complicated than that? My Honda is around the late 90s early 2000 vintage I think, and is remote driven not tiller if that makes any difference.
Cheers
Treny

Hi mate. You should be able to plug the new gauge directly into the existing wiring harness from your motor by matching the colours. Black is ground, black/yellow is ignition power, grey is the sender wire, red/white is the power for the back light. Don't worry about the back light wires if you don't need back lights. The bullets should plug straight in and the colours should match up on the wiring harness at the helm. If you get any weird tach readings like a drop off as you approach 3000rpm then you may need to install a 1k resister between the sender and ground at the back of the gauge, only install it if you get funny readings otherwise no need.

There should be 5 wires on your honda gauge. The R/W (12v) and B (ground) wires together are the little globe for backlight. The other wires are for your actual tach. The Y/B is switched 12v power (from the ignition switch), the B is ground and the G (grey) is the sender wire, it connects to your regulator/rectifier under the cowling (which is actually just a direct link to one side of the charge coil). You never mentioned the grey wire in your post, it should be there. Sorry if I've just doubled up on myself here but I wanted to clarify.

skronkman said:

There should be 5 wires on your honda gauge. The R/W (12v) and B (ground) wires together are the little globe for backlight. The other wires are for your actual tach. The Y/B is switched 12v power (from the ignition switch), the B is ground and the G (grey) is the sender wire, it connects to your regulator/rectifier under the cowling (which is actually just a direct link to one side of the charge coil). You never mentioned the grey wire in your post, it should be there. Sorry if I've just doubled up on myself here but I wanted to clarify.

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Thanks Mate!
I appreciate this info, my new tach should arrive in the next couple of days so will follow these instructions.
Cheers
Treny
(what a great forum)

You may need one of these rings for your new gauge to fit properly in the existing tachometer hole. The new gauge is a little smaller in diameter.

[h=5]Tachometer Bezel Kit[/h][h=5]
06380-ZV5-000AH[/h]
May be needed to install the smaller diameter original equipment tachometer in the standard 3 3⁄8 inch hole. Kit contains two black anodized aluminum bezel rings, needed for front and rear of mounting panel.

Mike

hondadude said:

You may need one of these rings for your new gauge to fit properly in the existing tachometer hole. The new gauge is a little smaller in diameter.

Tachometer Bezel Kit


06380-ZV5-000AH


May be needed to install the smaller diameter original equipment tachometer in the standard 3 3⁄8 inch hole. Kit contains two black anodized aluminum bezel rings, needed for front and rear of mounting panel.

Mike

Click to expand...

Thanks Mike I am having trouble locating this part in Australia I see they are available in the States at a reasonable price but the Postage added is quite a expensive. Any suggestions where I can get the part with reasonable postage?

Sorry, I am not familiar with anyone that ships to Australia. Maybe you will get lucky and the existing hole is very tight on the existing gauge and the new one will fit ok....but probably not.

You can probably get by with one on the front...I don't think I have ever put one in the front and one in the back.

Just thinking out loud.....the dimensions are 80mm inside diameter, 90mm outside and 3 mm thick. I am not sure where else something like this would be used...possibly as a shim or spacer in a truck transmission or axle.

Maybe a large o ring would work? A ring from a ring toss game? https://www.google.com/search?q=rin...ei=5LPCVMXpGISjNrC0hIgK&ved=0CAcQ_AUoAg&dpr=1

Sorry...just trying to think out of the box....they are colorful, though!

Mike

Try calling Honda marine in Dandenong South, Victoria. (03) 9709 8444. They often don't have the stock on hand but usually can get it in within 2 days. I think frieght is about $12. Or perhaps you could fashion your own out of 3 ply or an old bucket lid (like the ones on building sites or commercial margarine/mayonnaise comes in). Good luck. You're not in the south eastern suburbs of melbourne by any chance?

Hi hi guys and thanks for the help! I have the tachometer fitted manufactured a spacer myself. Tacho is working but reading way too high idle is showing almost 2000 rpm and at cruising it is maxed out at 7000rpm it is definitely not doing that. Any suggestions what is wrong? There are no settings on the tacho to change.

hondadude said:

Sorry, I am not familiar with anyone that ships to Australia. Maybe you will get lucky and the existing hole is very tight on the existing gauge and the new one will fit ok....but probably not.

You can probably get by with one on the front...I don't think I have ever put one in the front and one in the back.

Just thinking out loud.....the dimensions are 80mm inside diameter, 90mm outside and 3 mm thick. I am not sure where else something like this would be used...possibly as a shim or spacer in a truck transmission or axle.

Maybe a large o ring would work? A ring from a ring toss game? https://www.google.com/search?q=rin...ei=5LPCVMXpGISjNrC0hIgK&ved=0CAcQ_AUoAg&dpr=1

Sorry...just trying to think out of the box....they are colorful, though!

Mike

Click to expand...

Test to make sure your charging circuit is working correctly, look at the voltage on your battery before you start the engine, should be about 12.8v. Then start your motor and rev it up around 2500rpm and watch the voltage on the battery it should be rising up and getting to over 14v eventually. This means it's working correctly, else you may have a problem there and your tach signal comes from the regulator rectifier and charge coil. So a problem here can cause your tach problem.
Also try the resistor trick, on the back of the gauge you put a 1k resistor between the grey signal wire and the black ground wire. You can just poke the resistors leads into the bullet connections for testing this and if it fixes your issue then you can look at something more permanent. Honda do make an actual resistor assembly for this purpose but it's about $50 and a resistor on its own will set you back about 5 cents.

Treny,
did you ever sort this out - I have same issue reads 1.5 times high -- something about the motor having 6 poles and the tach set for 4 . I have a 2003/2004 bf40 so almost identical motor
i bouht the Honda traitor package but no joy there
I'm thinking of pulling the thing out and seeing if there is any switch inside it ?? If nothing then my plan was to make a new face on paper with all numbers 1.5 times what's on the current face, cause in a cheap skate
thdpriblem there is how to get the Bugger out ?
cheers grant
sydney aust

Look for a switch on the back of the tach? be sure the engine is off and switch the setting and try again. Use a non magnetic tip screwdriver just in case, with faria guages you push in and turn the switch and make sure it fully locks into position before you try it out. You may need to remove the bracket on the back of the tach to access the switch?