Intermittent starting problem

[notme]

Progress bud? Sunday vicarious troubleshooting you see....

[swbarnett]

Progress bud? Sunday vicarious troubleshooting you see....

Progress indeed.

I did some multimeter tests around the starter relay while the bike was in a "starting state" - all good. Later the same day we got back and it wouldn't start so I redid the tests - all dead. I electrically bypassed the starter relay and the starter motor did turn over. My thinking then (from my findings and the useful advise from this thread) was that the problem must be somewhere in the circuit that initates the relay when the starter button is depressed. As the earth continulty test on the relay plug failed I was thinking that the relay was not the problem as this was not done through the relay.

At this point I left things alone and walked away to think - "what are the components of the starter relay initiation circuit". From my limited knowledge I deduced that this boils down to the starter switch, kill switch and the wiring (I can't quite remember my reasoning but I had eliminated the clutch and side stand swith as the culprit).

The starter switch is obviously fine because the headlight goes out as it should. This left the kill switch as the next component to check. I went back to the garage and tried to start the bike - no go. I then rapidly flicked the kill switch on and off several times. Hey presto! Se's alive!

I then proceeded to dismantle the kill switch and found the contacts to be very dirty. A good clean, polish and reassembly later and, so far, fingers crossed, she seems to be starting every time.

[notme]

Good on ya. Some people just give up and throw it to a supposed expert - who would charge you a hefty fee for just cleaning some contacts! I know, because I've done it ;-)

I have slightly modified the advice in steps 2 and 5 of my thread here, based in part on this issue.

One other thing - if the fault reoccurs, DON'T say "oh fark, I didn't fix it after all..." rather say "hmmm maybe I didn't quite clean up that switch 100%" and/or "hmm it may not have been the switch, but at least now I know what it's NOT, and I know more than when I started"

[swbarnett]

To those of you that might be wondering. Yes, I tested the kill switch after re-assembly and it still works.

Cheers guys, your comments were very helpful.

[scumdog]

To those of you that might be wondering. Yes, I tested the kill switch after re-assembly and it still works.

Cheers guys, your comments were very helpful.

The XN85 has an intermitant similar problem, the engine whizzes over but no start, I SUSPECT it is linked to the kill-switch.

Since I've stopped using it I have had no further problems...but I'll bear your experience in mind and have a look into the kill-switch at soem stage.

[notme]

The XN85 has an intermitant similar problem, the engine whizzes over but no start, I SUSPECT it is linked to the kill-switch.

Since I've stopped using it I have had no further problems...but I'll bear your experience in mind and have a look into the kill-switch at soem stage.

Keep an open mind regarding fuel system too though - it's pretty unusual for a bike (except some ATV/dirtybikes and the like) to have the kill switch cut ignition but allow the starter to turn.

Then again, that's a pretty unusual bike!

[swbarnett]

Keep an open mind regarding fuel system too though - it's pretty unusual for a bike (except some ATV/dirtybikes and the like) to have the kill switch cut ignition but allow the starter to turn.

Certainly with my wife's Hornet the engine doesn't turn over with the kill switch engaged.

[BMWST?]

wasnt at all unusual at the time for the kill switch not to disable starter(was it?)

[notme]

Usually on older i.e. simple ignition and magneto type bikes the killswitch will disable spark (often by shorting ign to gnd). Often this type of simple ignition does not have a starter motor, because a starter implies a battery which means a charging system and so on.

Once an electric starter comes into the picture, if you think about the logic - why would you waste battery cranking over the heavy current draw starter? It's a really obvious indication to the user that the killswitch is off it nothing at all happens when you press the start button, and it saves power.

[swbarnett]

wasnt at all unusual at the time for the kill switch not to disable starter(was it?)

The starter motor didn't engage at all. There was no sound whatsoever (apart from maybe a bit of cursing from the temporarily stranded rider).

The problem was that the kill switch disabled the entire starter system (as it's supposed to do when in the correct position) due to dirty contacts.

[Gareth123]

I had the same problem as you did. Bike wouldn't start easily when it was hot and would lose a bit of power as well when it was running. Turned out the regulator/rectifier was breaking down.

Glad you got your problem sorted though.

[swbarnett]

I had the same problem as you did. Bike wouldn't start easily when it was hot and would lose a bit of power as well when it was running. Turned out the regulator/rectifier was breaking down.

Glad you got your problem sorted though.

Thanks. Bike hasn't skipped a beat since I cleaned the contacts.

[imdying]

Some people just give up and throw it to a supposed expert - who would charge you a hefty fee for just cleaning some contacts!

No, not just for cleaning some contacts. You're paying for the expertise in finding which set of contacts to clean in the first place.

[notme]

Sortof....substitute the word "experience" for "expertise" and that statement is true most of the time!

An auto sparky will have seen many problems in the past related to dirty contacts and similar, so for anything intermittent one of the first things he'll usually do is spray contact cleaner through the related switches and connectors. If the fault changes or goes away he knows where to look.

Even better is if he has had 20 bikes that week with the same fault, because that sort of rote learning means he can fix the fault in 2 minutes, still of course charging the minimum one hour labour

[imdying]

No, he is not going to find that fault and fix it in 2 minutes. You're over exaggerating the reality because without that over exaggeration the point doesn't stand up to scruitiny. Yes there are unscrupuolous vendors who will grossly over charge for 5 minute jobs, but in my motor industry time I've found them to be the exception... here in NZ the opposite is far more likely to apply (i.e. they go yep I know what that is when faced with a small common problem, and then drop tools and fix it for nothing). It is of course customary to turn up the next day with a dozen piss for them

I have no problem with people charging honest money for honest work, that's how they stay in business for the next time I need them... wanna see what I think reeks, check out the thread about my seat cowl.