660 Tenere Tacho Weirdness

[evanonearth]

Calling all ten rider...

Has anyone ever had any problems with the tacho on their ten?

Mine has gone a bit bonkers (2011 model 660z).

I've been doing some serious fettling for this years Sahara jaunt, one of which was to change the front cog from 15T to 14T, and what a difference that has made!

I'm not sure if it's a weird coincidence but during the first ride I had on it after fitting the 14T I noticed that the tacho needle started to go a bit weird.
It was working fine for a the first few miles but after a brief stop the needle started to go to zero then jump around, generally just going a bit mental. The bike however was running fine and revving fine. There were no warning lights and the speedo seems to be working fine.

When you switch the ignition on the needle sweep is only going to 4K then back to zero. When its running it's idling around the 1K mark but is only going up to 4K when you rev it, even though the engine is actually revving well beyond that, it's all a bit weird and I was wondering if the good people on here have ever seen the same thing.

I know the fuel gauge is generally a bit crap on the ten but mine seems particularly bad and I'm wondering if I've got a bad display unit.

Cheers,
Evan

[minkyhead]

it may well be a faulty wire to the tcho ...but in the past ive had two rectifier failurs ..honda blackbird mk 1 and two on both occasions

one of the early symptoms was elecrical failure ..and losing the tacho and speedo due to drain whilst on the move ...id check out the rectifier and charging system as a percaution ..it may well not be the case .. but as i say thats what happened when the rectifier started to break down

the guage on mine falls pretty quick when the last bar starts flashing i still have eight litres to go in the tank

[evanonearth]

Cheers minky,

I'll check that out, the battery has been draining but I was putting that down to not having had a good charge since it came out of hibernation.

Maybe there is a bigger electrical problem that's giving this rather odd symptom.

It's going in for new knobblies at the end of the month, so I'll get it checked properly then.

Thanks again for the steer,
Evan

[Andysr6]

Hi, I ran a 14T sprocket for about a year with no issues except the chain wore out quicker than I would have expected.
A friends Thundercat did something very similar and it turned out to be a fault warning of poor battery supply, he tightend the battery terminals which cured the problem. Andy

[Phil]

maybe an error code?

my fazer does it. If the needle sweeps round to 4k..it means an exup valve problem, if it sweeps to 6K it means something else and so on.

Just before my REG packed up on my Ten it did something similiar....but i mean just before....like, 10 mins before the bike died the needle started going a tad mental. hmy:

[MORT 666]

Go to xt660com. :whistle:

[enduro374]

Go to xt660com. :whistle:

+ 1.

[Tim Cullis]

I'm with minkyhead, my Tenere started behaving like that before the rectifier wires burnt out. The Tenere is well known for having a poor connection between the wires and the rectifier and it starts arcing. Mine was so badly damaged it needed a new wiring loom.

It started happening when I was offroad on the Rekkam Plateau near Figuig, then started behaving itself again. Then started happening again 500 miles or so further on near Midelt, then OK again. Then finally failed as I rode it off the ferry into Spain, again another 500 miles or so further on.

The solution (before this starts happening) is to take the rectifier connection to bits, fill it with silicon and make sure everything is well connected when you reassemble.

[evanonearth]

Thanks for the steer and great tip Tim, I'll strip down the connector and do that this weekend.
I'm off to Morocco on in in May for its first proper adventure, with the rest of the fudoo.org gang, and I don't fancy having the same experience you did, new loom sounds expensive!

While I'm chatting with you (as it were) can I just say a quick thanks for your great Morocco knowledge page on UKGSR, it's been an invaluable resource for our last two trips.

You da man!

[picos mestizo]

I've had a couple of Italian built bikes with Yam 660 engines with the same problem. I think the instruments are Italian & it's the Tacho head that goes faulty internally & I seem to remember it's a sealed electronic unit.
It'll lead you a right dance looking for it as it seems like an intermittent loose wire but in fact is a faulty component in the head.
Hope this helps. Good luck.

Sorry- just realised yours is a 660z which I believe is built in Japan, so I guess the above doesn't apply.