Help needed from an electrical Guru. Tacho needle spiking)

**wackyrider** · 30-04-2012, 10:00 AM

Good day guys,
I was out on the R1 (2001 model) on Sunday and i realised that my tacho needle started spiking. I was just riding sitting at around 4000rpm and you can see the needle jumping up to say around 7000-8000rpm. The bike was not revving though (seems like just a signal being sent).

Just later on after I stopped at a meeting point for about 30mins and when I hopped on the bike and turned the key... Nothing, dead. Switched the bike off and on another 2 times and it all came back on. It was a full power out as even the clock reset itself. Left for the ride and the tacho starting spiking again. After about 50kms or so the power (electric) started going and coming (even the dash was switching off and on) and I decided to pull over as the bike wasn;t running well. Took the seat off and checked the terminals, to check for a loose contact and all seemed ok. Decided to play it safe and rode back home, but this time with no issue at all.

Any ideas?

**Yella** · 30-04-2012, 10:14 AM

I would be looking for a bad earth/loose connection first up at
Battery
main earth points on motor/frame
ECU
and checking Reg / rectifier output

let us know how you go

**wackyrider** · 30-04-2012, 10:24 AM

The positive lead has been replaced when I made the new battery box and the positive high tension lead has been replaced with one I got from the wreckers (2nd hand). This comes in from the side of the negative lead and rubs slightly against the negative terminal.

This week I will strip down the bike to check all connections to be safe.

**wackyrider** · 30-04-2012, 10:25 AM

Will do Yella.

I also have a Multimeter on order which will come in handy too.

**Dynomutt** · 30-04-2012, 10:39 AM

From memory the Yamaha uses the tacho needle as a fault indicator, in the manual there should be a code to explain the fault for each needle position. It may well be that the tacho needle is showing a fault in one of the sensors on the bike, the TPS is often the culprit, as this one tends to go out of sync more regularly than others go down. check the fault code in the manual then test the component it is indicating.

**Redmohawk** · 30-04-2012, 08:01 PM

I would imagine a bridge or dongle needs to be attached to put ecu into fault diags, so not likely out of the blue I would imagine.

But a loose connector or your wires shorting etc will sure do all that jules. As already stated look for bad earth and your pos wire etc. A good electrical store (jacar) will have some spray contact/switch cleaner lube pull your connectors apart and check pins give them a spray and push back together firmly.

**wackyrider** · 01-05-2012, 07:56 AM

I will check all the contacts this week.

How do u test the Rec reg?

**Dynomutt** · 01-05-2012, 08:01 AM

On the early R1 as with the earlier YZFs there's no need to bridge like on the FI codes on the Gixxers for example. The tacho needle will spike to say 4000rpm to indicate a fault on a particular component.

3000rpm is TPS
4000rpm is speed sensor
7000rpm is EXUP valve
8000rpm is fuel sensor

These were cribbed from a Yamaha forum a moment ago

**wackyrider** · 01-05-2012, 08:20 AM

I want to check the batteryas well. But the fact that it lost all power then went back to normal again doesn't seem likely that it's a faulty battery to me. More like a loose or bad connection.

It was more the tacho needle jumping that confused me

**wackyrider** · 01-05-2012, 08:22 AM

Originally Posted by Dynomutt

On the early R1 as with the earlier YZFs there's no need to bridge like on the FI codes on the Gixxers for example. The tacho needle will spike to say 4000rpm to indicate a fault on a particular component.

3000rpm is TPS
4000rpm is speed sensor
7000rpm is EXUP valve
8000rpm is fuel sensor

These were cribbed from a Yamaha forum a moment ago

I wouldn't have expected them to have that back in 2001, but wow. Good to know. Only prob is I didn;t take note of what rev it was jumping to. I would expect for this to make sense, that it would have to consistantly jump up to the same place (say 7000rpm if it was the EXUP valve)

**Redmohawk** · 02-05-2012, 06:08 AM

Good info dyno thanks for the heads up, I to am supprized that a bike manufacter has thrown such ideas into a 2001 bike.

**Dynomutt** · 02-05-2012, 07:32 AM

The YZF750 had the same system back in 1995, so it's nothing new really, and I seem to think the earlier versions also had it.

**xa-mont** · 02-05-2012, 03:02 PM

if you need a multimeter i have one at home you can lend.

**wackyrider** · 02-05-2012, 03:50 PM

Cheers Trav. Got to find the time. Also have to look at the Landy now. Have to do the CV joints and possibly steering universal joints too.

**xa-mont** · 02-05-2012, 03:58 PM

well let me know if you need a hand. my arm is pretty much fine with nearly everything now. probably be in Bdale this weekend, but i'm free after work and whatnot.

**wackyrider** · 02-05-2012, 04:19 PM

Cheers. Need to get under the Landy to have a look to check if the universal joints are gone, which is what I'm hoping. Otherwise I'm not sure what is wrong.

I need to replace the CV joints as well though. Never done either so might just buy a manual. Your big jack might come in handy though. If I get the parts, I could get the Landy to your after work.

The bike I just need to take the bodywork off and go over all the connections, then take it for a test ride.

**xa-mont** · 02-05-2012, 04:30 PM

i think there may be a problem there... i'm pretty sure i've taken my big jack to Bdale already. i'm running on minimum tools right now :P
we should be able to do them without a jack though, it's high enough by its self.