sluggish starting on my 750X DCT

[Mike5100 2,061]

I had a 700X DCT for 14000 miles and the starter always churned the engine over brilliantly, but right from the off my 750 has seemed sluggish.  It has never failed to start but I am worried that it might let me down somewhere out in the wild in the depths of this winter.

 

So I have done some measurements this weekend.

Battery voltage after a long ride on Friday was 12.23v.  This seemed low so I put it on my very good battery charger (an accumate pro) which had it back to 'maintain' mode pretty quickly.  Imagine my surprise then this morning (Sunday) when I disconnected the accumate and measured 12.23v again on the battery.  I started the engine and it was sluggish as usual, but immediately afterwards (10 secs of engine idle) the battery voltage was 12.85v.  I left it a few minutes, started the engine again and after 10 secs of engine running it again measured 12.85v.

 

If anyone has any thoughts I would welcome them, as it doesn't seem right to me and I'd like to report it back to Honda with some suggestions.

 

The temperature today was 4 degrees.  I use a lot of heated gear but the heated grips have never switched off during a ride, and furthermore I used all the same gear on my 700X through last winter with no problems.

 

Mike

[Guest Hati]

It seems to me that your battery might be bad. Cold doesn't help, but it should not drop that much overnight. There is no telling how long a battery was sitting on the shelf before it was installed in the bike.

 

What was your charge voltage? It should be somewhere around 14 Volts when the bike is running past idle.

[Guest robson]

try to start the engine with charger on and you'll have your answer.

[Mike5100 2,061]

It seems to me that your battery might be bad. Cold doesn't help, but it should not drop that much overnight. There is no telling how long a battery was sitting on the shelf before it was installed in the bike.

 

What was your charge voltage? It should be somewhere around 14 Volts when the bike is running past idle.

Yes I can check that this afternoon - good idea

Mike

[Mike5100 2,061]

try to start the engine with charger on and you'll have your answer.

Possibly, but I'm charging it through the heated clothing outlet, so if the starter suck too much extra juice in, it could blow the fuse (or maybe damage the charger.  But your idea is sound - I could use jump leads from another battery and see if that makes it churn better.

 

Mike

[Slowboy 20,683]

try to start the engine with charger on and you'll have your answer.

Or most likely blow the charger.... As Joyce Grenfell nearly said, "robson, don't do that"

[trisaki 2,029]

See what battery reads with ign off then turn ign on shouldnt drop below about 12.2 ish if it drops below 12 battery scrap

[Tex 36,817]

It does sound very much like a duff battery. An excellent 'real world' test is to pull out the fuel pump fuse (so the engine can't start) measure the battery voltage (should be over 12.3) then crank the engine for ten seconds. A bad battery will frequently 'collapse' after four or five seconds. A good one should crank for ten without dropping below 12V.

For the record, my 750 cranks most vigorously (even in the coldest weather).

Edit: You can always call the AA and get their guy to test the battery for you. He will give you a 'pass' or 'fail' print out, which you can take to your dealer.

Edited December 7, 2014 by Tex

[embee 7,288]

Here's a useful flow chart for bike electrics, there will obviously be subtle differences between models but treat it as a general guide

http://www.electrosport.com/technical-resources/library/diagnosis/pdf/fault-finding-diagram.pdf

[Guest robson]

Or most likely blow the charger.... As Joyce Grenfell nearly said, "robson, don't do that"

 

been doing this many times with cars chargers and not a single problem. Properly built automatic charger

is resistant to something like that.

[Guest bonekicker]

Another brilliant idea from Mr Tex call the AA man let him sort it for you, just tell them the bike wont start, he will test the voltage and tell you the problem,they were very helpful with me. 

[Mike5100 2,061]

I think Tex's idea might give a better idea of whether it's a duff battery - I have a similar doubt about a caravan battery.  it can give decent voltages but tends to collapse after far too small a drain.  I will see if I can find the fuel pump fuse.

Mike

[Mike5100 2,061]

The odd thing is that I have just checked my email and a week after getting the bike new in January I asked them to check the battery as it seemed to be a sluggish starter.  It's now done 9000 miles since then and it's just the same - but has never failed to start.

Mike

[Mike5100 2,061]

Sorry to have wasted your time guys but I have discovered that the erratic voltage readings have been caused by a connection problem.  It's worth knowing this for another reason.  I have tended to mix Keis and Warmnsafe heated garments, and their plugs and cables look compatible, but they aren't.  The centre pin doesn't seem to make reliable contact if you mix the connectors.
When I was getting 12.23v I found if I rotated the male (Keis) plug in the Warmnsafe female socket, it would suddenly jump and stay at 12.85v.  And I am getting a solid 14.3v when the engine is running (even on tickover)
My starter still sounds sluggish though  
Mike

[JONO49 201]

Try putting a jump lead from the negative terminal to a good earthing point on the engine, to see if it's an earth connection fault? the readings you got from the battery are spot on....Anywhere above 12.68volts is healthy when cranking the starter put a multii-meter on the battery, it should not drop more than 1.5 volts! anymore and it might suggest an earth connection problem on the starter,(or brushes worn on the starter)  If you can access it also check the positive terminal at the starter for corrosion? (it's not unheard of on newish bikes) your charging voltage is bang on

[Mike5100 2,061]

Good thinking John.  Will try that tomorrow

Mike

[TheEnglishman 401]

try to start the engine with charger on and you'll have your answer.

 

 

err - a 'charger' is in no way going to supply the current a starter motor requires.

 

 

 

back to the OP - take the battery out and run a tester against it. Like other posters, it sounds like the battery is bad.  Or just connect your car battery across the bike battery and see how it starts. 

[Tex 36,817]

I was getting 12.23v I found if I rotated the male (Keis) plug in the Warmnsafe female socket, it would suddenly jump and stay at 12.85v.  And I am getting a solid 14.3v when the engine is running (even on tickover)[/size][/font][/background]My starter still sounds sluggish though  [/size]Mike[/size]

Right, 12.85 and 14.3 are good numbers. If the fault has, as you say, been there 'from new' I feel it's more likely to be a connection issue than a 'unit' (battery/starter) one.

Go through ALL the connections on the starter circuit using the 'volt drop' method.

Switch your meter to 'DC Volts' scale. Place one probe on (say) the battery terminal and the other on the wire bolted to it. Get an assistant to crank the engine. A perfect reading is 0.00 volts. A reading of 0.1 is unacceptable. There are videos of how to use this method on You Tube. Or, this tells you how in greater detail than I have time for

http://www.aa1car.com/library/voltage_drop_testing.htm

I suspect it will turn out to be a poor connection on the earth side of the circuit. Likely the battery - (Neg) to frame one. Good luck.

[JONO49 201]

err - a 'charger' is in no way going to supply the current a starter motor requires.

 

 

 

back to the OP - take the battery out and run a tester against it. Like other posters, it sounds like the battery is bad.  Or just connect your car battery across the bike battery and see how it starts. 

 

The Battery figures are spot on! Connecting a car battery will only assist the bike battery and not show the fault, unless the extra current makes the bad connection heat up a bit, there's no way of telling????

[embee 7,288]

Just flicked through the thread and can't find if you say anywhere what battery is fitted.

 

My 700 has a Yuasa YTZ12S, I imagine the 750 is probably the same item. The YTZ range have pretty high "cold cranking" current (CCA) capabilities, the 12S is 210A, the 14S is 230A from memory. These values are substantially higher than earlier YTX range equivalent batteries for example. Do you have a Yuasa YTZ12S or YTZ14S fitted?

[Marte 127]

My bike is getting a bit lazy to start up in these below cero cold mornings. So I've been asking here and there about a battery replacement and been offered the Okyami lithium batteries. Has anybody had lithium batteries mounted on the bike? They are supposed to be better.

[JONO49 201]

Stick to lead acid or Gel batteries, Have you checked the Elecrolyte level? top up with de-Ionised water then give the Battery a charge!

[Marte 127]

YTZ12S batteries are sealed, no way to check levels I think.

Why do you like them better than lithium ones?

[Tex 36,817]

Hi Marte, we use lithium batteries on our race bikes, because of the light weight. A 'big' battery weighs a fraction of it's 'wet' equivalent. They only need to provide sufficient power to run the ignition for four laps of the TT course, though.

Weight is much less of an issue on a road bike, so I would look at an AGM (absorbed glass mat) or gel battery. Well proven, reliable, affordable and capable of almost unlimited re-charge cycles (unlike lithium, which need specialist chargers and may not cope with being charged by alternator).

Good luck.

[Marte 127]

Thanks, Tex. I will probably end buying the Yuasa YTZ12S, which is AGM.