5th gen tacho and speedo delay

[Adie93]

Hiya people, I seek to have a delay with both my tacho and speedo, anyone have an idea on what could be the cause, here's a few scenarios, say i blip the throttle instead of a crisp rise and fall of the needle it will pause momentarily before coming back down, if I'm trawling along at a steady rate and I pick up the throttle the engine clearly picks up revs as expected however the tacho needle will hang fire for a little while before deciding its going to catch, an example would be 6th gear at 5000rpm to achieve 70mph, i can then roll on the throttle to approx 80mph and the revs will maintain 5000rpm sometimes for a good 5 seconds or so, same goes for speedometer, id describe it as latency if that makes any sense.

Its rather frustrating as i know it should be almost instantaneous, revs and speedo will also occasionally hold a lower or higher speed than road speed/engine revs due to this issue which is a little sketchy, I just dont like it and haven't a clue where to even start looking for a fix, however I'm off work tomorrow so a few pointers would truly be appreciated to get me started I've also a feeling its displaying a higher idle than the engine is actually spinning, again any help would be greatly appreciated,

Thanks!

Adie

[Bren]

Can't help with the rev counter as that goes into electrical territory which I'm crap at but there are some very knowledgeable members on here that help others a lot!

 

I would suggest you check the speed sensor which goes onto the front sprocket nut. This is a plastic piece that often doesn't get fitted back on to the nut properly and rounds out causing speed reading irregularities. 

 

Good luck.

[Adie93]

Hey man, thanks for the quick reply! First thing I checked was the sensor plastic nut and it's snug as a bug in a rug, the problem seems to be that both the tach and speedometer "pause" they never drop to zero like I've seen a few other posts mention, there's just a delay between what the bikes actually doing and what the instruments are doing which I won't allow myself to turn a blind eye too especially when the bikes potentially travelling at 5 to 10 mph over it's indicated speed due to the latency issue 🤣 on other news i managed 200 miles from a tank today!!

[vfrgiving]

For oddball instrument cluster behavior my first try is pull the two connectors at the back and clean with contact cleaner.  The plug interface Honda went with isn't the best.

 

This requires removing the front cowl.

[Grum]

And while you're doing as vfrgiving suggested.

 

Both Tacho and Speedo share the same power source and ground source. So make sure at the mounting screws for both instruments you measure a good ground which goes back to the Green/Black wire, and 12v that goes back to the Brown/Blue wire and to Fuse G 10amp. Check for any corrosion on the PCB copper tracks. Refer partial drawing attached.

[Adie93]

Thanks alot gents! Imma pop out and get some contact cleaner than I'll have the day to pull front coil and investigate! Thanks again,

Adie

[vfrgiving]

Spray the connectors on the blue and gray plugs and the copper tracks in the plug cavities.  I use Deoxit brand contact cleaner, but any electrical contact cleaner is fine.  Just don't scrub those copper tracks with anything.

 

[Grum]

And if all of the above doesn't work check the dreaded Orange Ground block, its the main cause of many strange Ground faults.

[Mohawk]

I'd just say to anyone out there with a 5th Gen to check the fairing below the headlight. There is a small infill panel that pops out to allow the parking bulb to be changed. It also pops out accidentally & then lets rain & spray in that corrodes the tracks on the dash circuit board. Just tape it up if you don't have the infill, its not visible so most people don't know its there ! ☹️

[Mohawk]

52 minutes ago, Grum said:

And if all of the above doesn't work check the dreaded Orange Ground block, its the main cause of many strange Ground faults.

I checked this block on mine & on opening it & removing the bridge pieces it all looked great. When checking the cables entering the block green corrosion was apparent. So I cut all the cables off the block & half a dozen had bad surface corrosion. So I stripped them back, cleaned up the individual strands with abrasive & intertwined & soldered all together then sealed with amalgamating over wrap. All my weird issues went away 👍 If you do this I would advise adding an additional thick ground wire to the bundle & run it direct to the battery negative terminal. 

[JZH]

On 9/17/2023 at 3:12 PM, Mohawk said:

I'd just say to anyone out there with a 5th Gen to check the fairing below the headlight. There is a small infill panel that pops out to allow the parking bulb to be changed. It also pops out accidentally & then lets rain & spray in that corrodes the tracks on the dash circuit board. Just tape it up if you don't have the infill, its not visible so most people don't know its there ! ☹️

 

Aka, the "dropped bike indicator"... 

 

Ciao,

 

JZH

[JZH]

On 9/17/2023 at 3:19 PM, Mohawk said:

I checked this block on mine & on opening it & removing the bridge pieces it all looked great. When checking the cables entering the block green corrosion was apparent. So I cut all the cables off the block & half a dozen had bad surface corrosion. So I stripped them back, cleaned up the individual strands with abrasive & intertwined & soldered all together then sealed with amalgamating over wrap. All my weird issues went away 👍 If you do this I would advise adding an additional thick ground wire to the bundle & run it direct to the battery negative terminal. 

 

I did exactly the same on my yellow bike.  However, having since gone down the "motorsports wiring" rabbit hole, instead of soldering I would bunch them all together and apply a massive brass crimp (maybe a Sealey 16mm2 or 25mm2 ring terminal with the ring part cut off), crimped using a Draper battery terminal crimping tool (the kind you slam with a sledge hammer), followed by adhesive-lined heat shrink with the end pinched off.  The ground wire can be used with that method as well.

 

Ciao,

 

JZH

 

 

[Bren]

I think I read once that those ground wires should be joined together into 2 groups as that's how they are in that orange block?

I've never had to do this, yet, but probably will one day so I'd like to be prepared.