Jump to content
Sign in to follow this  
xxxfb

Dct stalling problems

Recommended Posts

xxxfb

Hi. My son’s got a dct ( I only had the 700x), was riding to London from Oxford, thus bike at temperature, and slowed down for traffic. The bike then stalled. He started it but it would not reach tick over revs by itself and would not go in to gear. Just  before the stall he noticed that the bike seemed to be holding on to a longer gear for longer than normal. The battery was on the way out ( he knew about that!) and eventually it wouldn’t start at all. The garage says it’s just the battery, it may be, but I don’t know enough to understand why a poor condition battery can cause the dct to drop out.

Can anyone shed light, please.

Thanks

xxxfb

Share this post


Link to post
DCTPaul

had a battery issue the other week...

had stopped in 1 rather than N

when i went to start the bike a few days later...

not enough juice to get the DCT servos switching to get it in to N to start...

 

A few hours on the trickle sorted it.

get a new quality battery Yuasa? not a cheapy...

 

Its all a balance of sensors and brains...

low or bad battery, low or bad sensor output.

 

Edited by DCTPaul
  • Like 1

Share this post


Link to post
EastSussexPete
39 minutes ago, xxxfb said:

The battery was on the way out

  My DCT did the same after i dis-charged the battery by accident.  A couple of my past bikes performed poorly just before the battery gave out.

  • Like 1
  • Thanks 1

Share this post


Link to post
embee

If the battery was known to be weak, and then these symptoms happened, the obvious thing is to fit a new good spec battery. I would suggest also doing a quick superficial check of the charging voltage once it is up and running again with a good battery, at idle and also when revved a bit it should be giving a little over 14V at the battery terminals, in the range 14-14.5V typically. As long as it's not significantly more nor less than this it's probably fixed.

 

Vehicles which rely on a lot of electronics are a little sensitive to voltages far outside what they normally expect to see, it can affect the outputs from various sensors and if these exceed certain tolerances the systems may consider there is a fault and will then do various odd things.

 

As for a new battery, you really need something with a cold cranking capacity comfortably over 200Amps (CCA), the standard original spec battery for the NC is the Yuasa YTZ14S which has a CCA of 230Amps. Cheap batteries of a physical size similar to the YTZ14S may have a CCA as low as 120A and will not perform well.

  • Like 2

Share this post


Link to post
xxxfb

Thank you, these replies are really helpful. Being of the age where Honda had only just brought in the cb750, things like ELECTRONICS (😱) frighten me!
Cheers

  • Like 1

Share this post


Link to post
Steve Blackdog
29 minutes ago, xxxfb said:

Thank you, these replies are really helpful. Being of the age where Honda had only just brought in the cb750, things like ELECTRONICS (😱) frighten me!
Cheers

Aye, you knew where you were with kick starts!

Share this post


Link to post
Foxy
10 minutes ago, Steve Blackdog said:

Aye, you knew where you were with kick starts!

 

Especially if it went straight up your trouser leg and you didn't notice until the next red light😂😂 The bike was ok but my pride was dinted.

Edited by Foxy
Auto correct.
  • Haha 1

Share this post


Link to post
SteveThackery
4 hours ago, xxxfb said:

Thank you, these replies are really helpful. Being of the age where Honda had only just brought in the cb750, things like ELECTRONICS (😱) frighten me!
Cheers

 

Don't let them.  :)

 

Honestly, the basic principles are easy, especially at the level needed to make a good fist of diagnosing faults.

  • Like 3

Share this post


Link to post
Andy m
6 hours ago, Foxy said:

 

Especially if it went straight up your trouser leg and you didn't notice until the next red light😂😂 The bike was ok but my pride was dinted.

 Yep, done that. Tried to button the ankle of the flapping waterproofs on the move, failed, and the rest is embarrassing. 

 

Electronics are amazingly simple once you stop trying to diagnose a computer by resting a screwdriver on the case and listening for thrunging sprocket pre-ignition and such. They work, they don't work because something fundamental like power or earth or a cable connection is missing, they log a fault code. The battery diagnosis makes perfect sense. Even if it's not the prime fault it's the one you need to fix before going further. Try diagnosing a carb fault with a tank half full of water and you'll get the idea. 

 

Andy

  • Like 2
  • Thanks 1

Share this post


Link to post
xxxfb

Absolutely. The battery replacement was sense, it was the “what comes next” that concerned me. 
Cheers

Share this post


Link to post
larryblag
On 12/01/2020 at 00:08, embee said:

If the battery was known to be weak, and then these symptoms happened, the obvious thing is to fit a new good spec battery. I would suggest also doing a quick superficial check of the charging voltage once it is up and running again with a good battery, at idle and also when revved a bit it should be giving a little over 14V at the battery terminals, in the range 14-14.5V typically. As long as it's not significantly more nor less than this it's probably fixed.

 

Vehicles which rely on a lot of electronics are a little sensitive to voltages far outside what they normally expect to see, it can affect the outputs from various sensors and if these exceed certain tolerances the systems may consider there is a fault and will then do various odd things.

 

As for a new battery, you really need something with a cold cranking capacity comfortably over 200Amps (CCA), the standard original spec battery for the NC is the Yuasa YTZ14S which has a CCA of 230Amps. Cheap batteries of a physical size similar to the YTZ14S may have a CCA as low as 120A and will not perform well.

Yes, undervoltage can cause all manner of symptoms with electronics. Especially when environmental conditions (cold) exacerbates a weak battery. 

Share this post


Link to post
larryblag
On 12/01/2020 at 13:47, SteveThackery said:

 

Don't let them.  :)

 

Honestly, the basic principles are easy, especially at the level needed to make a good fist of diagnosing faults.

In the age of the digital I'm still rather impressed at what we accomplished by purely analogue means just a few years ago. Look up "Drop Out Compensation" for video recording and playback equipment and you'll see what I mean. :frantics:

Share this post


Link to post

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×