Go Back   Horizons Unlimited - The HUBB > Technical, Bike forums > Other Bikes Tech
Other Bikes Tech For Technical Questions on bikes not listed in the other forums.
Photo by Daniel Rintz, Himba children, Namibia

The only impossible journey
is the one
you never begin

Photo by Daniel Rintz,
Himba children, Namibia



Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 21 Oct 2006
simmo's Avatar
Contributing Member
Veteran HUBBer
 
Join Date: Nov 2002
Location: melbourne
Posts: 555
Voltage reg/Rectifier

OK here goes travelling genius's...sss

Now I have an aircooled Italian 900cc twin that is only testing at 12 volts across the battery terminals at 3,000 or there abouts revs. I believe I should expect 14.5 volts if everything is functioning normally.

As the bike was running rough on three quarter to full throttle when I got it and had been sitting for a while, I assumed blocked up carb jets. I can say categorically that this is not the case anymore! My italianised hands now understand the Mikuni CV carb with oil line heaters very well.

The bike still runs poorly, breaking down (poping, backfiring, running on one cylinder etc) when the throttle is openned wide. I suppose I am trying to find out how to determine wether its the Reg Rec thats clapped out, the coils under load or the stator/alternator itself. Fuses all look good, and I have fiddled with the conectors.

Tips on how I might go about resucitating the Crapati welcomed.....and all you schwinhundt lovers, the G/S has been parked. The new one handles and has brakes but clearly reliablilty is yet to improve....



alec
__________________
Close to Antarctica and a long way from reality
Reply With Quote
  #2  
Old 21 Oct 2006
beddhist's Avatar
Contributing Member
Veteran HUBBer
 
Join Date: Sep 2003
Location: Whangarei, NZ
Posts: 2,214
Have you checked the connectors?

With everything still connected measure the voltage into the RR unit. Voltage should increase as revs go up from idle. Set the V meter to AC for this. There will be three wires (assuming it does have a three-phase alternator...) and you should have the same voltage the three ways. You can also disconnect these wires and measure resistance, should be about equal the three ways and no connection to ground. Any other measurement and it's the alternator winding. If this checks out OK try another RR.
__________________
Cheers,
Peter.

Europe to NZ 2006-10
Reply With Quote
  #3  
Old 21 Oct 2006
mollydog's Avatar
R.I.P.
Veteran HUBBer
 
Join Date: Aug 2003
Location: california
Posts: 3,822
A simple question first.....How's the battery?
So many times guys over look this simple element!

Is this a Ducati?

I would get hold of a service manual so you can go through all the
electrical trouble shooting steps.

There are always several resistance tests you can do to find the fault,
sometimes they show where it lies and sometimes not.....I've seen
bad stators that show resistance within spec....so who knows.


The batt may test at 12.5 volts but could have a bad cell and causing
problems.

But your system should be putting out about 14 volts as you've pointed out.
So who knows. But a good battery is very important so that the other
components can operate at spec.

Also look for any corrosion, clean all connections, tighten all connections,
look for frayed or abraided wiring looms, split sections, bad kinks, missing
or unplugged or bodged plugs or wires.

Good luck!

Patrick
__________________
Patrick passed Dec 2018. RIP Patrick!
Reply With Quote
  #4  
Old 21 Oct 2006
Dodger's Avatar
Large Golden Member
Veteran HUBBer
 
Join Date: Aug 2005
Location: BC, Canada
Posts: 1,085
You haven't said what make and model bike you have so any help can only be very generalised .
If the bike has a manual ignition advance system ,you should check this for correct operation as it may not be advancing enough [ or even at all ] at higher revs.
Bad spark plugs can also cause a high end misfire on one cylinder .
But ,as you have pointed out .the alternator may not be charging so put a known good battery on the bike and ride it a short distance to find out if that's the cause of your misfire and then check alternator as suggested .
Weak or stiff carb diaphragms can also be the culprit but you 've already checked them .
__________________
Blessed are the cracked, for they let in the light. - Spike Milligan
"When you come to a fork in the road ,take it ! When you come to a spoon in the road ,take that also ."
Reply With Quote
  #5  
Old 22 Oct 2006
simmo's Avatar
Contributing Member
Veteran HUBBer
 
Join Date: Nov 2002
Location: melbourne
Posts: 555
Thanks guys, Beddhist thats the clue I was seeking, I'll have a go and let you know.

Yes it is a Ducati, a 900 Monster and once running properly will be my regular transport, I am sick of fixing the old BMW. I even have a spare tank to modify for a decent touring range.

It has a good Batt, new spark plugs, filters, belts and oil, new emulsion tubes and lovelly clean carby jets. Caps, fuses and connectors checked. I am just trying to isolate the problem before I waste more money on unnecessary expensive replacement parts.

cheers
__________________
Close to Antarctica and a long way from reality
Reply With Quote
  #6  
Old 23 Oct 2006
Contributing Member
Veteran HUBBer
 
Join Date: Jul 2002
Location: Sydney, NSW, Australia
Posts: 1,362
Your first gess at the rectifier/regulator is a good one - that is the 'normal' failure mode .. much like the airhead rotor on the bm.

One test - does the ret/reg get warm/hot? If cold then it is not doing much work. If hot it is doing too much .. may be not working the right way. I suspect the ret/reg may be passing AC to the battery .. and the battery won't like it .. err if the battery is hot .. it is the ret/reg !!!!!

Certainly a battery voltage that is not over 13 when the motor is running so revs is not good ... fix it before riding anywheres ..

Checking the 'alternator' - Measure the AC output from the alternator .. should go up and down with engine revs .. umm how many volts .. errr that will depend on if it is loaded or not .. ie if the retifier reg is working .. but it should be around the 10 to 20 volts ac level. If my theory is working...
__________________
---
Regards Frank Warner
motorcycles BMW R80 G/S 1981, BMW K11LT 1993, BMW K75 G/S

Last edited by Frank Warner; 23 Oct 2006 at 02:49.
Reply With Quote
  #7  
Old 24 Oct 2006
Registered Users
Veteran HUBBer
 
Join Date: Apr 2003
Location: Cape Town, South Africa
Posts: 303
Battery check:

Check for fluid level and top up with destilled water to max. (the Ducati pobably has a sealed maintenance free batt - skip)

Charge your battery with a good quality charger. While charging the battery voltage should go up to 14.4 volts max. after 12 hours or so depending on state of the battery and type of charger used.

Disconnect the charger. Battery voltage should be some 13.5 volts dropping slowly (you will need a good digital voltmeter, if you have something else throw it away and buy a good one, they ain't expensive).

After the battery has been standing for at least a couple of hours (best one day) the voltage should have settled to 12.8 Volts. If it is lower the battery is old. If it's below 12V you should get a new battery. A battery with a bad cell will always drop down clearly below 12V within a day. A typical voltage for this would be 10.5v approx for a battery with a broken plate (cell shortcut, this one will never exceed 12V even if freshly off the charger). You often have a combination of a bad cell and a weak battery which will show a voltage of less than 10V one day after charging.

You can shorten this procedure by visiting a reliable battery shop with your battery. They have testers but they might also want to sell a new battery :-/

Alternator check:

Once charged you put the battery into the bike and start the engine. Your voltage should be above 12.8 volts with the engine idling. Most charging systems will feed some 14+ volts into the battery without revving the engine high (at 2000 to 3000 rpm). The voltage should modulate a bit from idle when reving the engine up and should reach more than 14V fairly quickly.
12 volts at 3000 rpm is IMHO a clear indication of one faulty coil in the alternator. Note that measuring the resistance of the three coils will give correct readings in most cases and even against ground the coils will not "leak" if tested with a resistance meter / diode tester.
Besides testing the voltage output of the three phases of the alternator, which is often tricky without making new cable connectors or stripping insulation off the bike's wiring, only applying high voltage to the coils will reveal an earth leakage of one of the coils past the insulation against ground. A good automotive electrics shop will be able to perform this test and they will also be able to rewind the coils or give you an address to get the problem fixed.
Rewinds are usually superior in quality and often also provide higher power output of the generator. A rewind often only costs a fraction of a new replacement part.

In your case:
The battery is permanently low on charge and whilst the battery will for some time provide enough power for the starter it will not have enough voltage for the ignition causing backfire and rough engine run. Sooner or later the battery will also fail prematurely.

Regulator / rectifier:

Within 20 years of working on motorcycles (the last 12 professionally) I never had a regulator / rectifier malfunctioning except an old selen plate model on a Black Bomber and a similar piece of shite on an also otherwise very sorry Duc 350 twin. The modern 3 phase rectifier / regulator units usually don't break.

Alternator coil problems are relatively common on older bikes (10 years+) and seem to happen more often on "vibey" bikes as mechanical stress is a contributing factor to break the insulation of the coil. The problem can also occur on fairly new bikes (in my case a KLR 650, 1 year / 15000 km) The symptoms were identical to your bike.
Reply With Quote
  #8  
Old 25 Oct 2006
Contributing Member
Veteran HUBBer
 
Join Date: Jul 2002
Location: Sydney, NSW, Australia
Posts: 1,362
Exclamation Rec/reg failures.

Quote:
Originally Posted by lecap
Regulator / rectifier:

Within 20 years of working on motorcycles (the last 12 professionally) I never had a regulator / rectifier malfunctioning except an old selen plate model on a Black Bomber and a similar piece of shite on an also otherwise very sorry Duc 350 twin. The modern 3 phase rectifier / regulator units usually don't break.
You have never seen a VFR then .. they do the rec/reg all the time!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!! Do a web search ..

And it is fairly common on ducks too....

I've had two fail on a honda 250 twin ... personal experience.

------------------- Techincal - One of the three SCRs in the Rec/reg fail short circuit ... usual cause is a 'hot spot' in the junction ...
__________________
---
Regards Frank Warner
motorcycles BMW R80 G/S 1981, BMW K11LT 1993, BMW K75 G/S
Reply With Quote
  #9  
Old 28 Oct 2006
simmo's Avatar
Contributing Member
Veteran HUBBer
 
Join Date: Nov 2002
Location: melbourne
Posts: 555
An update...well the stator windings in the alternator have checked out OK. The regulator rectifier had failed. A new one has been put in and I am now getting a between 13 and a heady 14 volts at the battery with the bike running. Stopped the Battery is steady at 12.7 volts.

Pleased with the result I then set out for a ride expecting my back firing to have vanished and Ducati ownership to be one of reliability and noise...well umm..should have known better....

I still have the problem..as it is occuring on both cylinders I doubt it is a coil, lead or plug cap. Having two fail at the same time seems unlikely unless the failed reg/rec has damaged them both.

Another check of the plugs revealed carbon deposits which brings me back to poor ignition or an overly rich mixture.

I will have a play with the needle and urrg float settings and see if that makes a significant diferrence and change the leads and caps.

The bike runs fine at idle and when its not under load, all farts and bother on 3/4 to full throttle...screams main jet doesn't it?

cheers and thanks for your help guys its been very helpful even if I haven't solved the problem yet.
__________________
Close to Antarctica and a long way from reality
Reply With Quote
  #10  
Old 29 Oct 2006
simmo's Avatar
Contributing Member
Veteran HUBBer
 
Join Date: Nov 2002
Location: melbourne
Posts: 555
Well, I am going to have to do plug reading lessons...The bikes electrics are fine and the black carbon on the plugs wasn't on the electrodes, they were very clean this time around almost no staining at all, combined with flaming backfires a guru supected the bike was way to lean.

Taping up one of the snorkles on the airbox proved this to be a reasonable assumption as the thing went significantly better.

Next step is to take the tops of the carbs and raise the needles to richen up the mixture and begin to enjoy this thing.

Exactly why this worked so well when you would think carbs would suck what air they needed and the mixing would take place inside them... completely escapes me..

looks like mysterious backfiring and rough running was at least two problems with potentially similar effects..tomorrow we should have the second and last sorted...
__________________
Close to Antarctica and a long way from reality
Reply With Quote
  #11  
Old 1 Dec 2006
Registered Users
HUBB regular
 
Join Date: May 2003
Location: Cardiff
Posts: 31
Talking Italian reliability; an oxymoron?

Now I’m just going for a wild stab in the dark here but there’s no chance that the choke could be stuck on is there?
I just hope that its sorted in time for me to play with it at Christmas
Reply With Quote
  #12  
Old 6 Dec 2006
simmo's Avatar
Contributing Member
Veteran HUBBer
 
Join Date: Nov 2002
Location: melbourne
Posts: 555
Got me to work today smarty pants!
__________________
Close to Antarctica and a long way from reality
Reply With Quote
  #13  
Old 8 Dec 2006
Registered Users
HUBB regular
 
Join Date: May 2003
Location: Cardiff
Posts: 31
When they said that 24 hours of reliability was something only the Japanese could manage they didn't know what they were talking about
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 Registered Users and/or Members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Help! How do I connecting a cigarette lighter socket kit to an XT battery? Iain Yamaha Tech 20 28 Sep 2006 14:37
Voltage converters and travel plugs for people from the UK Iain SOUTH AMERICA 4 22 Sep 2006 08:35
African Twin Voltage regulator Ironbutt Honda Tech 4 2 Sep 2006 11:07
Alternator output on '82 R100RS John Roberts BMW Tech 29 6 May 2006 14:42
voltage converters hughc Equipment Reviews 1 7 May 2002 11:24

 
 

Announcements

Thinking about traveling? Not sure about the whole thing? Watch the HU Achievable Dream Video Trailers and then get ALL the information you need to get inspired and learn how to travel anywhere in the world!

Have YOU ever wondered who has ridden around the world? We did too - and now here's the list of Circumnavigators!
Check it out now
, and add your information if we didn't find you.

Next HU Eventscalendar

HU Event and other updates on the HUBB Forum "Traveller's Advisories" thread.
ALL Dates subject to change.

2024:

Add yourself to the Updates List for each event!

Questions about an event? Ask here

HUBBUK: info

See all event details

 
World's most listened to Adventure Motorbike Show!
Check the RAW segments; Grant, your HU host is on every month!
Episodes below to listen to while you, err, pretend to do something or other...

2020 Edition of Chris Scott's Adventure Motorcycling Handbook.

2020 Edition of Chris Scott's Adventure Motorcycling Handbook.

"Ultimate global guide for red-blooded bikers planning overseas exploration. Covers choice & preparation of best bike, shipping overseas, baggage design, riding techniques, travel health, visas, documentation, safety and useful addresses." Recommended. (Grant)



Ripcord Rescue Travel Insurance.

Ripcord Rescue Travel Insurance™ combines into a single integrated program the best evacuation and rescue with the premier travel insurance coverages designed for adventurers.

Led by special operations veterans, Stanford Medicine affiliated physicians, paramedics and other travel experts, Ripcord is perfect for adventure seekers, climbers, skiers, sports enthusiasts, hunters, international travelers, humanitarian efforts, expeditions and more.

Ripcord travel protection is now available for ALL nationalities, and travel is covered on motorcycles of all sizes!


 

What others say about HU...

"This site is the BIBLE for international bike travelers." Greg, Australia

"Thank you! The web site, The travels, The insight, The inspiration, Everything, just thanks." Colin, UK

"My friend and I are planning a trip from Singapore to England... We found (the HU) site invaluable as an aid to planning and have based a lot of our purchases (bikes, riding gear, etc.) on what we have learned from this site." Phil, Australia

"I for one always had an adventurous spirit, but you and Susan lit the fire for my trip and I'll be forever grateful for what you two do to inspire others to just do it." Brent, USA

"Your website is a mecca of valuable information and the (video) series is informative, entertaining, and inspiring!" Jennifer, Canada

"Your worldwide organisation and events are the Go To places to for all serious touring and aspiring touring bikers." Trevor, South Africa

"This is the answer to all my questions." Haydn, Australia

"Keep going the excellent work you are doing for Horizons Unlimited - I love it!" Thomas, Germany

Lots more comments here!



Five books by Graham Field!

Diaries of a compulsive traveller
by Graham Field
Book, eBook, Audiobook

"A compelling, honest, inspiring and entertaining writing style with a built-in feel-good factor" Get them NOW from the authors' website and Amazon.com, Amazon.ca, Amazon.co.uk.



Back Road Map Books and Backroad GPS Maps for all of Canada - a must have!

New to Horizons Unlimited?

New to motorcycle travelling? New to the HU site? Confused? Too many options? It's really very simple - just 4 easy steps!

Horizons Unlimited was founded in 1997 by Grant and Susan Johnson following their journey around the world on a BMW R80G/S.

Susan and Grant Johnson Read more about Grant & Susan's story

Membership - help keep us going!

Horizons Unlimited is not a big multi-national company, just two people who love motorcycle travel and have grown what started as a hobby in 1997 into a full time job (usually 8-10 hours per day and 7 days a week) and a labour of love. To keep it going and a roof over our heads, we run events all over the world with the help of volunteers; we sell inspirational and informative DVDs; we have a few selected advertisers; and we make a small amount from memberships.

You don't have to be a Member to come to an HU meeting, access the website, or ask questions on the HUBB. What you get for your membership contribution is our sincere gratitude, good karma and knowing that you're helping to keep the motorcycle travel dream alive. Contributing Members and Gold Members do get additional features on the HUBB. Here's a list of all the Member benefits on the HUBB.




All times are GMT +1. The time now is 08:17.