2006 honda bf90a, tach/hour issues

K

krc

Member
Hi -
I have been seeing random tach errors on my port engine. It will be at 3500 cruising then jump up to 6k, back down, then just wildly fluctuates. Engine is not changing rpm based on what I can hear. It has been going on for a year, but not too annoying as most of the time it works fine. Now the hour meter on the starboard tachometer is not showing any hours. No digits whatsoever.

Any ideas? I guess I need to pull the tachs off and check the connections. Or is the "no digits" on the hour meter indicative of a general meter failure?

Thanks
 
I'll mention that I had problems with the Honda tachometer on Journey On. It would read a very low rpm, then a high on, without the engine sounding any different. I'd hit it a couple of times and then it'd settle down.So, I finally pulled it out. It was a Faria gauge. Ordered a new one and installed it. Identical fit which now says "Faria" instead of "Honda". With a new clock.

Boris
 
Start off with cleaning all connections with spray on contact cleaner, plug in and out at the plugs, and burnish an ring terminals. You may want to apply a very small amount of conductive grease to contacts when re-assembled.

If that doesn't correct the issue, then change out the gauges.

Check for 12 volts when the ignition is on (include cleaning ignitions wire connectors).
 
Removed terminals, cleaned as best I could, checked that with ignition "on" I was getting voltage to the unit (12v or so) - same as on the port tach. Still no display for the hour meter. I guess time to replace. Thinking same unit best otherwise it wouldn't match to the port tach.

Anyone have a part number? I am thinking the BF90 was using this:
37250-ZW5-010ZA

Or better alternative part#?
Thx
 
I have twin 50s and have noticed a similar issue with my starboard tach. The tach would display excessive RPMs when running the throttles about the same. No difference in sound of motors.
I tested this while running the 50s at idle. After they warmed up a bit, the port displayed just a hair under 1K. The starboard displayed 2 to 2.5K. Using a multi-meter set to Hz, I checked between common and signal on the tachometer wire landing posts. Both tachs were at around 23-24Hz (if I remembering correct). The idling sound test also told me that the tach display was not true. I just wanted to confirm that there was no "racing" of the starboard. I have not looked into getting a new tach yet. After they continued to run & warm, they both settled in at just under 1K rpm.
 
That's the correct Honda part number. It's a Faria tach with a Honda label. The equivalent Faria tach is: Faria Model 32840; black, 7000 rpm, hour meter.

I'd get whatever is cheaper, they're the same tach.

Boris
 
I see the same thing on my 199x BF90a's Tach. I tap the glass a couple of times and it comes back down to where it should be. The engine noise never changes so i accept it as a mechanical issue due to the vibration of running etc. I also trust my ear more than the tach anyway.
 
Replaced the starboard tach and hour meter is working fine now. I had checked all the connections, etc.. and the old one was still "blank". So I think the culprit was indeed the tach unit itself.

Thanks everyone.
 
Back
Top