Weird starting problem

tom3c75

tom3c75

Hero member
Location
Cape Town South Africa
Been having a weird starting problem on my 3C over the last two weeks.
The problem has manifested in the following stages.

Initially, from cold, the engine began to turn over very sluggishly when the starter button was pressed. 
Seemed just like a low battery.  If I switched off the engine immediately after it eventually took, and then restarted it, it fired up directly with no sign whatsoever of a tired battery. 
No issues when the engine was warm.   

I charged the battery, but the symptoms remained.  So, I removed and opened the starter motor, expecting to find a mess inside.    However, apart from one brush that was stuck in its holder, the starter was in remarkably good condition.  The brushes were not unduly worn.  I freed up and lubricated the sticking brush and put it all back together again.  Symptoms remained.

Then, later, and again when cold, the bike would not even turn over at first start.   
Switching on the lights while trying to start it resulted in the lights dying completely.
However, switched on immediately afterwards, by themselves, the lights, horn, etc worked perfectly. 
Then, if I turned off the ignition and tried to start the bike again, it took without any problem whatsoever!

I then checked and tightened the earth cable and the connections at the fuse box.  This seemed to help, as I managed to start it first time from cold on a few occasions.

Then the bike would not start when warm.    After switching the ignition off and then on again a few times, the bike would start normally.  Bike bump starts without any problem.

Finally, when in the warm non-start mode, after I had turned off the ignition switch, and the on again, but not yet pressed the starter button, the bike fired up by itself!    I tried the kill switch, but it made no difference, engine just kept running.    A bit of a rattling noise was evident.

Did some searches on the forum, and figured I needed to check the starter clutch.   
Removed the starter clutch gear, again expecting carnage inside. 
I have not split the starter clutch, but everything was intact and seems in good condition. 
The rollers are perfect, springs are all in one piece and the plungers seem OK.  The clutch plate is not broken.      There does not seem to be a problem in this area.

So, next step is to open up the starter relay.   
I have opened the right hand handlebar switch, but can?t see anything amiss, but I?ll anyway clean it out.   

Not sure if a faulty ignition switch, which seems OK, would produce the above symptoms?
May have to remove the starter again and have it checked by a sparky.

Any ideas would be appreciated.
 
Burnt contacts in the starter relay I recon, the old tin box Bosch ones can be mended or any generic high current relay can be substituted.


    Keith
 
I have found heavy corrosion from time to time on the heavy duty cables between starter and relay and relay and battery.
Only evident when you cut back the insulation.
Check your leads to see if they are contributing to the problem.
 
i had the autostart thingy taht you describe. White knuckles when the starter began to smoke. Tried everything that sprung to mind, desperate to prevent the bike -and house- to burn down. Eventually it stopped by itself.  faulty starter relay.
 
Ensure you have a good Cable from Battery to Solenoid and from Solenoid to Starter. As far as the Solenoid goes: OutBoard Marine Solenoids do the same job and are build much better. Old Evenrude, Johnson and Mercury Solenoids work and cost practically nothing.

Ensure your Battery Ground Strap to Frame is in good shape.

If that don't work, providing the Brushes look good and wired correctly, and you're still smoking or have a weak or nil starter response, the Stator Winding are either shot or the Field Coils are probably shorting to the Starter Casing. You can check this by using an Ohm meter.

I always wire the Starter SX,  through primary low volt Solenoid Coil to the Neutral Sx Ground.  This prevents you from engaging the starter in Gear or when your running which if you inadvertently hit the starter SX, can engage the starter clutch, with a weak Back Plate, and spin the starter ashes. In other words, you have to be in Neutral to start the engine. You don't want your ride running off the side stand when you hit the Starter SX  - I don't care for the Clutch Depress Starter Safety SX method.
 
For the starter motor to self-start when you switch on the ignition, the relay would have to already be engaged before you turned the ignition switch, or immediately engage when the ignition comes on. In the first case, the contacts in the relay could have stuck in the "on" position from the last time you pressed the starter button. In the second case, the relay switching circuit would have to have self-energised for some reason like the starter button being stuck on.

You've confirmed that the starter button and wiring is OK, so it was most likely the relay misbehaving. The relay contacts are just lumps of copper, and can overheat and partially weld themselves if they get too hot from repeated attempts to start. I'd guess that's what's going on in your case. ZBut I'd suggest that the sticking relay is an effect of your starting problems, not the cause.

Sounds to me like your starter motor is faulty, despite the fact that it looks OK inside. It's evidently drawing a lot of current because it's killing the lights and (possibly) cooking your relay. Any starter motor that's pulling heaps of current but not doing much cranking is not well. Sounds like it has an internal short circuit. A few months ago, my Jota had exactly the same poor starting symptoms as those you describe. Turned out to be shorted-out stator coil windings in the starter motor. They're not easy to re-wind so I ended up buying another starter motor.

Cam

 
My normal starting from cold procedure involves caffeine and nicotine, but not necessarily in that order.

James

Concur with sus starter relay, but in the process you have checked/cleaned/fixed many things that may or probably will need looking at at some stage in your adventure.

j
 
To check if it's a solenoid problem simply SHORT the Hi-Amperage Terminals on the Solenoid with a BIG Screw Driver or Pliers and see what the Starter Does.

A short in the Starter can damage the Hi-Amp Secondary Contacts in the Solenoid - It's just a Hi-Amp Rely. Sometimes, the Low Amp Primary Winding in the Solenoid Rely is weak or the Hi-Amp Contact is pitted; noted by a clicking sound, but this has nothing to do with a Starter that SMOKES.

It could be possible the Starter Star Cluster Gear is Worn out and dragging - Never seen this happen on a Laverda Nippon or Bosch starter drive.
 
FFS have a holiday both of you please. Go away.

Tom, Cams reply#5 is pretty much what I would say, but add that any auto electrician can check and hopefully recon the starter motor, I had the same problem and they skimmed the commutator and replaced the earth side brushes and it's been working 100% since.
 
Thanks for the suggestions guys.
The plan is to check the relay. 
However, it makes sense that if it is damaged, that I should find the cause.   
Seems I need to pull the starter again and I will have it checked by a professional.

Guess I can't really complain:  this is the first starting problem I've had on the bike in 38 years!

Tom
 
Sounds odd but the really old Auto Electrician who sorted mine years ago powered up the stater motor off the bike and held the gear sprocket,whatever it is,against a softwood post and routed some timber off.His version I expect of loading it to see if it had some guts.I said he was old school.
 
Tom, you can save yourself a fair bit of time by using starter jump-cables direct battery/starter and small bypass cables (I have a pair with alligator clip each end) to bypass switch wiring. Use this to isolate where the problem lies.
However it is never amiss to just go through and refurbish the whole system on such an old bike anyway.
 
Hi Tom these starter problems are a pain, and may be windings within the starter seems strange how it kills the lights, on my 120 Jota when the starter got caught by the starter clutch as the litttle bolts had come out (on the later clutches) and all but destroyed the armature by over spinning it would kill all the power within the electrical circuit, my problem was a bit more extreme than yours though.
 
Hi Tom

I would start by doing a thorough test on the battery a load test would be a good one. It could be that a cell is collapsing when cranking and when cold is the time that there is the most load on the battery internally. Understand what you are saying and that once started then OK but to me it sounds like a battery type issue.

Sometimes it is the simplest of things which are overlooked.

If the battery is OK then you need to do some voltage drop tests when cranking, you can a meter across the battery to start and see what voltage is when cranking. If you under around 10 volts... then you have a current draw issue.

Brett

 
tom3c75 said:
The plan is to check the relay.
Click to expand...
reckon ya should replace it.  old relays ain't worth the risk.
a few months ago, the contacts welded shut on Clyde's relay. ya gotta be quick to get the battery leads undone before it smokes itself!!  
got me a good used relay off an early K series BMW.  just bolts in, same shape,  Bosch  0332 002 161

,,
tom3c75 said:
,, I tried the kill switch, but it made no difference, engine just kept running.    A bit of a rattling noise was evident.
Click to expand...
reckon the 'rattling' was the starter clutch catching up with the engine at a slow idle,  before the relay contacts let go again??
that's what Clyde was doing when the contacts welded shut big time!

Mark
 
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