Topic: Bike won't start (electrical issue)

[1980cm400t]

I went to ride my bike to work this morning and it wouldn't start (electrical issue).  I commute every day on my bike (1980 cm400t) and this is the first time this has happened.  Some details: all the lights worked with the key in, the starter solenoid emits a single click when the starter button is depressed (the engine makes no attempt to turn over), I bump started it and rode it to work without any other issues, after getting to work the electric start still doesn't work.  I am fairly confident the problem is not the battery, the charging system is not particularly strong (running with the high beam on nonstop drains the battery in a week) but previously when the battery was weak the starter would engage and the engine would crank slowly.  Because I can hear the starter solenoid click when I press the starter button I suspect that is not the issue either.  I am thinking that the graphite brushes are worn out.  Is anyone else familiar with the symptoms of starter brush failure? Also where does one find replacements brushes (if that is the problem)?

[grcamna2]

Try jumping the starter solenoid w/ a large flat blade screwdriver across the the 2
large terminals:the positive from the battery to the starter power cable;if the starter turns over its ok,if not you may have corrosion on some terminals or wires.
I would check all of those connections & the starter button in your right handlebar switch. The starter is a pain to work on...,but that may be your problem.

                                       Let me know how it "turns"out for you.

[1980cm400t]

It starts when i jump it with a screwdriver.  I will check the switch for corrosion but I suspect that the solenoid gave out.  does anyone know where a cheap new solenoid can be purchased?  Bikebandit has them for $81 but that seems a little steep.

[kirkn]

No need to check the handlebar switch - if the solenoid clicks at all, it got what it needed from the switch.

A solenoid is a solenoid, so lots of other stuff should be able to be made to work without too much effort - junkyard, AutoZone, Pep Boys, etc.

I've also read of disassembling similar solenoids on one or two other sites and giving the main internal contacts a bit of cleaning (sandpaper) and being good to go.  Never done it myself, but I think I'd start looking at that solenoid for how to take it apart.

Meanwhile, carry that large screwdriver with you (or however you can jumper those two wires together once you've taken the solenoid out for refurb) and keep commuting!

[lucky]

WRONG thinking.

If the lights or horn work and the solonoid even clicks one time the problem is the battery connections. Clean them with baking soda and water and sand paper.

The battery connections get a grey greasy like coating on them that prevents the starter from being able to draw enough current to start. Every time the seasons change from warm to cold the electrons will not flow as easily as they do in the summertime.

Remember you cannot diagnose ANY electrical problem until you have a solid known source of 12 volts. Remember that.

[kirkn]

While I agree with the idea of corroded battery terminals, I disagree with the diagnosis in this case.

If corrosion at the battery terminals was the issue, the starter wouldn't function via a 'screwdriver-jumper'.  The corrosion wouldn't care if that connection were being made by a good solenoid or by a jumper.

Since the jumper DID work, battery terminal corrosion ain't it.

IMHO.   

[grcamna2]

Do you have a Motorcycle salvage yard not too far from you "1980 CM400T" ?
I live in an area where there aren't any & I have been stuck looking on CL and
Ebay ALL summer.I hope you can find one not too far from where you live & if they
have one ask the attendant if "you can take it right outside to do a quick install
to see if it works";I'm not sure if they will let you,but they may.

[lucky]

While I agree with the idea of corroded battery terminals, I disagree with the diagnosis in this case.

If corrosion at the battery terminals was the issue, the starter wouldn't function via a 'screwdriver-jumper'.  The corrosion wouldn't care if that connection were being made by a good solenoid or by a jumper.

Since the jumper DID work, battery terminal corrosion ain't it.

IMHO.   

I did not diagnose your motorcycle problem.
I only gave you one thing to check.

If the headlight and horn work then the battery terminals should be cleaned to make sure enough current can be drawn by the starter.

When you used jumper cables you were basically using clean wires.
You did not say if the jumper cables were connected directly to the battery posts or if they were clamped on top of the posts with the motorcycle cables on the posts.

To see if the starter is at fault, remove it from the motorcycle and use jumper cables on it directly. You will have your answer.

[kirkn]

You did not say if the jumper cables were connected directly to the battery posts or if they were clamped on top of the posts with the motorcycle cables on the posts.

But we all DID say.  The original advice, which I seconded, and the original poster's reply was that the "jumper" was not "jumper cables" but a screwdriver directly across the solenoid contacts and the engine started right up.  That's why I guessed that battery terminal corrosion wasn't the problem this time.

BUT, you are very correct in suggesting it be checked, because it certainly can be a problem!  Been there, done that. 

Kirk

[grcamna2]

I'm with you Kirkn...I think he might have corroded connections & possibly a
solenoid problem.I would like to physically see the bike; it sure is tough to check
for a problem w/o the physical machine right in front of me.

[1980cm400t]

I found a brand new solenoid from http://www.stuff4bikes.co.uk/ for £ 23.85 or $37.85.  they shipped it to the states in a week.  I will be installing it tomorrow we'll see if it works

[grcamna2]

Did your solenoid come in...how does it work for you ?

[1980cm400t]

Problem solved! the new solenoid works and is almost identical to the old one.  The only change is the rubber mounting sleeve has vertical as opposed to horizontal mounting slots so i just swapped the new solenoid into the old sleeve. 

[grcamna2]

Great ! It's always nice to have a "turn key" situation and ride alot rather than work on it Alot & ride once in a while.