Thanks for the tips...

I have a feeling I probably just ordered the first part I don't need...

What exactly is the function of that small black 3/4 inch square relay mounted behind the battery on the left side?

Is that where the 5 pin relay sold by RPM goes and will it plug right in to the 4 wire connector??

I feel I lost power to the tach first and it was followed by an intermittent power loss to the ignition and or fuel system during the next 6 or 7 minutes and then it died after that. I will test a few more electrical systems to see exactly what is now working and what is not.. So lucky that didn't happen on a major bridge or tunnel here in Vancouver..

gyrfalcon,

Nice words from Pat, but I am just an electronics tech, not really a bike tech. I do agree with Pat; grounding can be elusive or unreliable on any bike. You want shiny metal secured to shiny metal, at every electrical connection. Dull metal is corroded metal (so, a high resistance, a poor connection). Clean the connections to shiny-new with a small wire brush. Don't be shy about running a new dedicated ground wire connection (lug) on top of any grounding terminal.
Put gentle pressure on switches like the kill switch, and maybe the ignition key, to check their reliability. To get the bike running in the shop, install a temporary jumper wire across any normally-closed switches, and temporarily disconnect any normally-open switches.
I would suspect that a wire to your tach or engine has chafed, and now touches bare wire to the frame somewhere. Release the ties that secure such wiring to the frame, and check the insulation for wear. You can get brush-on insulation for wiring from the better auto-parts stores, or Amazon. Separate any suspected wiring, brush on the new insulation, let dry, and re-secure the wiring to the frame with Ty-Wraps that are not too close to the old locations.
Electrical problems typically can take days to locate, and minutes to fix.
Keep us posted.

A sudden interruption would indicate a short or ground fault or a failed relay.
 Not the case from your description...you had  a gradual loss of power.

A slow decline in power indicates a partial interruption from the electrical transfer typically from a loose connector or dirty switch.
 Look for arching on your connectors.

Check the power circuit to the ignition box. From the fuse block it runs through the run/stop switch on the handle bar.
 I speak from experience. I had a high RPM intermittent studder I traced to my run/stop switch.
I ran a temporary jumper from the + terminal of my battery to the 12v + wire directly into my ignition box....the studder went away... so the problem resided in the power feed to my ignition box...then I worked backwards to find where the interruption was occurring.......a dirty run/stop switch.

Avoid buying electrical parts until the culprit is found. Don't ask me how I know this...

As always...While you're at it, check your Red plug connector: https://fjowners.com/index.php?topic=19557.0

Speaking of Red, stay tuned, we have a bloke on our forum called Red and he is an expert in electrical issues, so he may have have some good insight for you...

Electrical gremlins are frustrating to try to find, but typically easy to fix.

Cheers
Pat

 Hello everyone,

Re 1989 FJ1200

I was out on a trip today and as i stopped at a light i noticed my tach was reading zero.. as I started driving
the tach was rising slightly but below normal. Over the next few blocks it started running worse and worse
and I pulled off to a side street as the bike died. After calling a bike towing outfit i was back home a few hours later.. I started reading that this could be caused by the 30 amp relay so I ordered one from RPM. He mentioned this was a universal relay and not a Yamaha one. I am still trying to find out if the small black relay behind the battery on the left side is this relay or if that could have caused all this. Or if a universal pin relay would plug into the connector with 4 wires on my bike.. So far reading through the manual I don't even know for sure where this 5 pin relay is located as the one behind the battery has 4 wires.. When I turn the key on I can hear some noise in that relay and the green neutral light is not working.
I have a recent new battery and all the fuses in the case behind the battery tested ok. Any tips on what may have caused these sudden problems today would be greatly appreciated!
.
Thanks!

What you need is a '72 Harley 2-stroke golf cart.  Like the one I need to sell.  Needs an inverted fork conversion.

You can't find a 170/60-17 Michelin Pilot Road 5?

Quote from: jvb_ca on May 02, 2026, 10:51:59 AMI'm in need of new tires for the FJ. Been way to long...ugh... I did the YZF600R rear wheel conversion years ago and always ran Michelin Roads 170's on this wheel as that's what fit on rim and gave enough clearance to chain. Worked great, handled nice but I am now having a hard time finding comparable 170's now. Can anyone confirm a 180/55 will fit on this 5in wide wheel and give chain clearance? I thought I read somewhere/sometime on here that someone actually did this? And it squeaked in there?
Cheers....Jake

On my 85, I run Avon tires with 170 at the back and it is already tight.

Sorry to hear you won't be making it this year.  Hopefully everything gets sorted out on your end.

Haven't ordered the shirts yet.  Will do so on May 8th. 

Its all in the geometry...

Some tire sizes are listed the same but vary between manufacturers. I run Continental and it clears the chain. The Dunlop in the same size rubbed the chain. Others might have similar experiences.