GSX 250 starter solenoid issue

[ukjules]

Thought I'd go for a burn and tried to start the bike
GSX 250, and got the inevitable click....
How is this happening to me....
Starter solenoid issue:

Battery 12.7v stood so good
Not done this before but have been taking battery on and off to fix my other bike .
pic attached. (tis earthed on chassis via it's body and a wire to loom - for ignition)

After hitting it and checking earth's it will after say 5 mins turn over. I don't think the adjustments had anything to do with it. sometimes it works sometimes it doesn't.

Took starter off bike.
Test 1
- provided power and it clicks ok. (it clicks on bike too)
Test 2
- energised solenoid with MM on posts @ 200ohm settings and displayed 10ohms
q) what result am I looking for ?
Test 3
- on bench non energised - Mm at 200 ohms and probes to earth on solenoid body and ignition wire.
result = 4 ohms
q) what result am I looking for ?

tomorrow :
- I'll make sure earth is sound on bike as from body of Solenoid. I can't see how this is an issue but will check.
- will add power direct to starter just to check. assume this works though as it does when solenoid bursts into life.
- I assume I can bridge solenoid posts to start but not tried that yet.

I had 4 pages of notes from past years to test a solenoid all of them impossible to understand so having to start afresh.

new solenoid from m&p - 9£ (and can add it to my growing order from them ...)

what's think and any more tests I can do ?
and what do my results mean ?

[bwringer]

Solenoids are normally dead reliable. They make the gound connection through the mounting bolts, and most common issue I've seen with these on many bikes is that the plate they're mounted on is rubber mounted, and that plate is not grounded (earthed) correctly. Maybe the ground wire from the frame to the mounting plate broke, or was missed when re-assembling, or there's corrosion or paint under the terminal, the ground wire is getting weak, etc.

If you do need to replace the solenoid, you can find one meant for a lawn tractor at any home store. In the US, they're around $15 - $20.

[ukjules]

you are so right about the plate and earth ... been there ..
I will clean up and check earth but I have been caught out before with what you say and earthed the plate. worth re.checking though - agree as I have disturbed things.

seems logical as I have to disturb things to get battery out of gsx and ig has been fine for years until just now.

was interested in MM results and how different to a working solenoid .
like my
Test 2
- energised solenoid with MM on posts @ 200ohm settings and displayed 10ohms

shouldn't it be 0 ohms ?

anyway will clean connections and earth tomorrow.

GS / GSX not doing well.So out with the RD 250D. I'm running out of.bikes to ride.

[pdqford]

Thought I'd go for a burn and tried to start the bike
GSX 250, and got the inevitable click....
How is this happening to me....
Starter solenoid issue:

Battery 12.7v stood so good

Not sure how you came to th conclusion that the starter solenoid is the issue.
Just because it clicks doesn't mean it is the issue.

Just because the battery stood at 12.7 volts is good.
But what does the battery read while pressing the starter?

Ohms don't tell me a lot on heavy amp draws like the starter circuit.
I'd look for voltage drops, first in the solenoid circuit as bwringer mentioned.
With the MM on the 20 volt dc scale, with the +meter probe on the battery + post
and the - probe on the small wire that activates the solenoid, press the starter button.
The meter will read the voltage dropped on the power side of the solenoid.
you want a very small number, like .02v

Next put the + meter lead on the metal base of the solenoid
and the - meter lead on the NEGATIVE batter post and press the starter button.
The meter will read the voltage drop on the ground side of the solenoid.
You want a very small number, like 0.2v.
If that reading much higher than 0.2v, see bwringer's post above.

Next we need to test the power and grounds of the starter circuit for voltage drops.
Follow the same procedure with the positive MM lead on the positive post on the battery,
and the negative lead on the power post of the starter.
Hit the starter button and the meter will read th voltage drop on the power side of the starter circuit.
You want a number that is less that 0.4v.

Noow move the + lead of the MM to the case of the starter motor and the negative probe to the
negative post of the battery.
Again you want less than 04 volts dropped on ground side of the starter.

Note, use the battery posts, not the battery cable connection as it may be the issue

Let us know your readings

[ukjules]

OK I have done some tests on the solenoid.

(Assume the starter will always run when poweed directly and when posts bridged starter works !

Also this morning I cleaned base of solenoid and made sure plate earthed ok.
Tests done after I did this.

What do these results mean ? when it seems to start the bike this morning ?
oh and i charged the battery overnight too.

the issue is the bike starts . hasn't not started this morn ?
Will it harm the bike , solenoid etc if i use the bike like this as tests fail ?

Test 1: Fail ?
Voltage drop on power side
MM pos probe TO Battery +
MM neg probe TO Ignition wire (Connected to loom)
Ignition off - 12.7v
Press start (Bike starts) intermittant issue it seems
Needs to be a very small voltage 0.2v.
RESULT - 12.7v poss a bit more - but bike starts immediately and voltage remains at 12.7v (This on suspect GSX Solenoid)

Test 2:
Voltage drop on ground side
MM pos probe TO Metal base of Solenoid (as earthed by base)
MM neg probe TO Battery - (Negative)
Ignition off - 0.0 v
Press start (Bike starts) intermittant issue it seems
Needs to be a very small voltage 0.4v.
(If higher check grounds)
Result - 0.12v (This on suspect GSX Solenoid)


Edit - starter tests now done

Test 3: Fail ?
MM pos probe TO Battery +
MM neg probe TO power post of Starter
Ignition off - 12.7v
Press start
Needs to be a very small voltage 0.4v.
Result - 12-13v

Test 4:
MM pos probe TO case of starter motor
MM neg probe TO Battery - (Negative)
Ignition off - 0v
Press start
Needs to be a very small voltage 0.4v.
Result - 0v

[ukjules]

AND
an additional question - what about on my previous resistance tests where the powered on showed 10ohms of resistance when I can see via the interweb it should be 0.2ohms ISH ?
test

- energised solenoid with MM on posts @ 200ohm settings and displayed 10ohms ?


I am not trying to be the ' big deal ' here I genuinely only provide the analysis... but really want to know is that figure a indication of issues ?

trust me info appreciated as once and for all I am making legible notes .

[pdqford]

ok i have done some tests on the solenoid.

Test 1: fail ?
voltage drop on power side
mm pos probe to battery +
mm neg probe to ignition wire (connected to loom)
ignition off - 12.7v

doesn't mean a thing with ignition off.
Must have current flowing through the circuit to measure voltage drop.

Press start (bike starts) intermittant issue it seems
needs to be a very small voltage 0.2v.


result - 12.7v poss a bit more - but bike starts immediately and voltage remains at 12.7v (this on suspect gsx solenoid)

i suspect that is open circuit voltage, as the bike starts immediately.
When the bike starts you let go of the starter button.
This shuts down current flow on the power side of the solenoid control.
No current flow / no voltage drop!!!!!!
What you saw is battery voltage and/or charging voltage.

Test 2:
Voltage drop on ground side
mm pos probe to metal base of solenoid (as earthed by base)
mm neg probe to battery - (negative)
ignition off - 0.0 v

again, doesn't mean a thing without current flowing.

Press start (bike starts) intermittant issue it seems
needs to be a very small voltage 0.4v.
(if higher check grounds)
result - 0.12v (this on suspect gsx solenoid)


edit - starter tests now done

test 3: fail ?
mm pos probe to battery +
mm neg probe to power post of starter
ignition off - 12.7v

again,...........

Press start
needs to be a very small voltage 0.4v.
result - 12-13v

you are dropping all the battery voltage some place between the
battery + post and the starter post. Therefore there is no voltage
left for the starter motor to use

test 4:
Mm pos probe to case of starter motor
mm neg probe to battery - (negative)
ignition off - 0v

again.......

Press start
needs to be a very small voltage 0.4v.
Result - 0v

because all the voltage was dropped on the power side.
Therefor they is no voltage available to be dropped across
the starter itself, and none to be dropped across the starter's ground side.

as for this intermitant thing you mentioned,
check the contacts in your starter button.

[ukjules]

ok I'll have to think on those explanations.

what you are suggesting is my solenoid is working perfectly ? (it seems to be madly)
and of course the tests had different results as it worked .

only when it doesnt fire up can you test the voltage drop and expect results as you showed ? I'll assume so.

just so know what I did to make this happen .

- battery charged overnightsl
- POS battery to solenoid cable was a bit freyed. it could have touched the frame. I have bodged this and will make another battery cable. it has fired up every time since I did these things.
- cleaned earth connections and various wires.

I have not checked the starter switch or cleaned .
the starter switch when pressed 'always' at very least made solenoid click.

today testing out and about.on bike - zero start issues !

so almost dead yesterday and today after what I did no issues.

it's that freyed POS battery wire isn't it ? the one that is so hard to put back and bends terribly to fit ?
could that cause what I noticed ?

[uk gs nut]

Those solenoids can be stripped and the heavy contacts inside cleaned. De solder the thin trigger wire remove the nuts from the studs then remove the screws. Watch out there is springs inside. When cleaned re assemble and solder wire back on. Check and clean the start button in right switchgear, there are brass contacts in there. A lawn tractor solenoid from a large garden centre will be easy fitted also.

[Rich82GS750TZ]

Seems like a lot of work for a $15 item at the local Tractor Supply.

[ukjules]

clearly you (rich) are not a mender of things . I like to mend rather than throw away. understand why something doesn't work.

but anyway I simply want to know why my bike would not start and the solenoid just clicked.
the reason if you read seems to not be the solenoid but connections. to confirm.

I can buy a solenoid for 9£. it seems it would not help my issue. it looks like what I thought I disturbed something constantly having to remove the battery.

I so would if time try and mend my solenoid if I ever needed to ! even if it took me 5 evenings .

[rphillips]

Seems to me this has got too complicated. The solenoid works by 12v from starter button, through the little wire to an electromagnet. That electromagnet slams a plate, sometimes washer, up against the bottom of those 2 big lugs. If you hear the solenoid click, the electromagnet has slammed the plate up to those lugs, that is what makes the click, the plate hitting the lugs. Sometimes the plate or washer gets burnt or corroded and when it hits the lugs it does not make a connection, no start, may hit the start button a few times and hear the click, till one time the plate slams up and does make connection and eng. starts. Your picture shows your solenoid is put together with screws, most have brads or rivets that make them way more aggravating to work on. Carefully take the thing apart, being careful to remember how it goes back together, and clean the plate or washer and bottom of both lugs, sometimes can just flip the plate or washer over to have a new surface to contact lugs. Are different shapes and designs, but all work basically the same. I ain't guaranteeing anything but have fixed several this way. If you get in there and find something you can't fix, like he said, any parts or lawn mower shop will have one that will work. ,plus you gain the knowledge of how these things work for next time needed.... Good luck.

[Rich82GS750TZ]

No, I mend aplenty. But I also have a good idea of what my time is worth. Carry on.

[ukjules]

ok ok guys - if you read there is nothing wrong with the stator after dojng some tidying of wires etc it seems

the analysis I posted backs this up.

it seems to be ok after I
- charged battery overnight
- cleaned ground connections which are not ideal with the plate the solenoid sits on
- noticed the POS battery wire to solenoid post was freyed due to having to take the battery out so many times. if you have a gsx you will know what I mean.
(I have ordered battery cable crimpers for new wire)

the above has resulted in never having a start problem today.

all notes taken !

time to ride the bike .... and await the other issue (gs550 stator return)
thanks for help as always

[pdqford]

Just to pick up on what rphillips posted (and good description of what happens inside the solenoid) if you want to measure the condition of the contacts between the plate/washer and the bottom of the two solenoid lugs, with your MM on the 20v dc scale, place your probes on those two solenoid lugs and hit the starter button. In effect, that will allow an alternate route across the two lugs. The high impedance of the MM will not let current through the meter, but the meter will display the voltage that can't pass through the washer/lugs connection because of resistance in the connection. You don't want more than a one or two tenths of a volt dropped across those two lugs.

And your mention of the condition of your battery cable brings up the point of why I don't trust measuring ohm resistance on the high current battery cable. When the MM is in ohm scale it puts out a fraction of an amp from the battery inside the meter. If even one strand of wire in that battery cable is good, it can allow enough current through that strand so that your MM thinks there is little to no resistance in the cable.
Now remove the MM from the cable and reconnect the battery cable from the battery to the solenoid. Hit the starter button and let the battery send 50+ amps through the cable. If there is only a few strands of wire in that battery cable that are intact, they will not be able to handle that load (as opposed to the load the ohm meter places on those few strands). Those few strands will heat up like a toaster wire creating massive resistance to the point not enough current can pass through to crank the starter. If you have your MM connected between the battery + post and the starter relay + post, your MM will display the voltage being dropped that the cable couldn't handle.

Agree that the cost of firing the parts cannon is insignificant, but I find it educational to learn how it should work, and why it doesn't work. Then pull the trigger and see how well you did.