Trouble hot starting

[AMCQ46]

Carl,
It didnt give me any problems last night when I was out, so I have done no more trouble shooting..........and in my head I am confident that it will restart even if I have to wait a few mins for it to cool down, so I am going to wait for it to get worse so it will be easier to diagnose!

my short list is is based on things that are getting hot with the engine:
1) starter stalled or brushes
2) engine earth
?? dont know whats next!

not sure how the starter solenoid can be efected by heat, but will look at that and also the reg/rec when hot to recheck

[Sbikerbud]

Its still on the original auto ccts.

I have ordered another starter power feed cable (£31!!!) and will be checking the charging again tomorrow (hopefully it will be as sunny as they say it will).

The only thing i can think of that hasn't been mentioned is some sort of problem with the starter clutch getting 'tight' when hot.

i have thought of just replacing the solenoid and buying a brush set for the starter...but funds are limited unfortunately. I'd like to replace the reg/rec, stator, starter, solenoid and fit manual ccts but it will have to be done over time....and thats something i don't have as i want to use it for a hol in 7-8 weeks time

[Sbikerbud]

Maybe i need to change the ccts, perhaps i have a problem developing there?

[sirch345]

I've replied in blue writing.

Its still on the original auto ccts.

I have ordered another starter power feed cable (£31!!!) and will be checking the charging again tomorrow (hopefully it will be as sunny as they say it will).
Unless you know for sure that is what's causing the problem it's a bit pointless spending money on something you may not need, especially as you say "funds are limited unfortunately". If you try out my suggestion with the jump lead first you may find that cable is not the problem.

The only thing i can think of that hasn't been mentioned is some sort of problem with the starter clutch getting 'tight' when hot.
One thing at a time. You need to eliminate the easiest repairs first.

i have thought of just replacing the solenoid and buying a brush set for the starter...but funds are limited unfortunately. I'd like to replace the reg/rec, stator, starter, solenoid and fit manual ccts but it will have to be done over time....and thats something i don't have as i want to use it for a hol in 7-8 weeks time
Try out the tests I suggest with the multi-meter and jump lead first. No point in throwing bits at it just for the sake of it. Save your pennies for what is needed to be replaced.

I know you say yours are standard CCT's, which they most likely are, but they could have been modified internally (stopper mod) which you can't see from the outside. If that was carried out incorrectly you could have a problem from the CCT's when the bike is hot. If one or both CCT's are causing to much tension on either of the cam chains then you will get a squeak or chirp as some call it on start up when the engine is hot. If they are completely standard CCT's without any modification you will not be getting start up problems from them.

Chris.

[tony.mon]

The only other (fairly rare, but I've come across it several times now) issue with the starter is the two gears on a common shaft which transfer rotation form the starter motor output shaft to the sprag clutch.
Occasionally these fail. They should be tightly connected on to the common shaft, so that if one turns, the other turns as well.
But occasionally the shaft can spin inside one of the gears, meaning that although the starter motor output turns; the sprag clutch doesn't turn. Normally a horrible screeching noise occurs at the same time.

Doesn't sound like your problem, but it seems a goo idea to mention it, while you're troubleshooting your problem.
Secondly the sprag clutch rollers can wear, go out of round, and fail to operate the sprag clutch properly. Then the starter motor spins but doesn't turn the engine over compression properly.

A new set of sprag rollers isn't expensive, IIRC.

But I agree with Sirch; use the diagnostic suggestions he's made and you should be able to isolate the issue without just buying a new everything.

[Sbikerbud]

I ordered a cable because the end of mine looks a bit grubby where it connects to the terminal (starter end), i've cleaned and lubed it but you never know.

I started it from cold yesterday with no trouble, then today from cold....no joy for the first two presses of the button, so now its started doing it from cold too. I couldn't try the jump lead you suggested as they are in the boot of the missus car and she has gone out for the evening.

Anyway...i got my dads multimeter and wired it up to the battery terminals and got the following readings....
1) ignition off = 12.80 volts
2) ignition on = 12.58 volts
3) starter pressed and volts dropped to near enough zero (i didn't keep the button pressed for long enough for it to register on the display) on the third press of the button it started, spinning the starter at the normal speed i might add.
4) at idle = 14.58 volts
5) at idle with lights = 13.35 volts
6) at idle with no lights but brake lights and indicators 13.95 volts

So i hopped on and took it for a 20mile ride
7) at 4-5k rpm whilst riding = 14.38 volts
at 4-5k rpm whilst riding with lights = 13.35 volts
9) at 4-5k rpm whilst riding with no lights but indicators and brake lights= 13.95 volts
10) at 4-5k rpm whilst riding with highbeam, indicators and brake lights = 13.25 volts

So i got home still charging steady at the above values for both running and tick over, turned it off, turned it on and it starts just fine with battery volts dipping to just 10.8 while actually turning over on the starter motor.
For my mind this sort of rules out the charging system being at fault

When it happens it doesn't even turn over once it turns maybe a quarter of a revolution of the starter motor.

The previous owner mentioned nothing about modding the CCTs and he's had it 7 years (then again he mentioned nothing about starting issues either the git )

[Wicky]

starter motor cable so checked that and it was corroded on the starter motor itself,

If it was corroded like that under the rubber boot then theres a chance that if the fibre seals on the bolt that goes into the starter have perished then the starter could be damaged internally and is slowly croaking.

Mine went like yours and cured by replacing the starter motor with a second-hand one and religiously greasing up under the rubber hood to keep corrosion at bay.

[VTRDark]

I ordered a cable because the end of mine looks a bit grubby where it connects to the terminal (starter end), i've cleaned and lubed it but you never know.

You could have just crimped a new terminal on.

couldn't try the jump lead you suggested as they are in the boot of the missus car and she has gone out for the evening.

I might be wrong but when jump lead was mentioned, I don't think it was meant as literally a jump lead as in the type you carry in your car.
A jump lead is a diagnostic term for a wire with a crocodile clip on either end. It can be used to bypass parts or get a direct feed from a power source etc. Just a long enough bit of wire of similar circumference will do, strip the ends and stick a couple of terminals on or hold it place.


Charging system is all looking fine.

I'm wondering whether it is the starter starter/starter solonod sticking. Next time it does not turn over. Stick the bike in gear, give it a nudge forward, then try and start it.

(:-})

[sirch345]

couldn't try the jump lead you suggested as they are in the boot of the missus car and she has gone out for the evening.

I might be wrong but when jump lead was mentioned, I don't think it was meant as literally a jump lead as in the type you carry in your car.
A jump lead is a diagnostic term for a wire with a crocodile clip on either end. It can be used to bypass parts or get a direct feed from a power source etc. Just a long enough bit of wire of similar circumference will do, strip the ends and stick a couple of terminals on or hold it place.

Carl that was exactly what I was referring to, a car type jump lead. It needs to be heavy duty to carry the amps from the battery.

Sbikerbud, things are looking good with the multi-meter readings. Going by those I'd say you don't have a problem with the rectifier, charging or the battery.

When it happens again if you can try the jump lead from the battery live (+) terminal to the starter motor live connection, if the problem is still there you can rule out the solenoid. If it's gone it's either that cable you're replacing or the solenoid.

If you haven't already, check the connections to make sure they are tight, not just hand tight, on the battery {both live and earth (earth, battery and engine end) connections and on the solenoid.

Chris.

[babysitter]

Had same starting fault with mine had to give 3 or 4 go's on the start button to get it to turn over changed battery / regulator mod to R1 /starter motor & soleniod and leads still the same found the faut was the intermediate gear from the starter motor fitted s/h gear and starts like new hot or cold.
PS have s/h soleniod if you need one

[VTRDark]

Carl that was exactly what I was referring to, a car type jump lead. It needs to be heavy duty to carry the amps from the battery.

Thanks chris, my mistake then. I was thinking of a heavy duty car jump lead and visions of sbikerbud trying to connect huge crocodile clips on a small (well small in comparison) connection. I realize it needs to be a fairly chunky cable that why I said similar circumference. To small a diameter cable will just melt or overheat and too large, would that not loose some power in the excess thickness of cable and slow the current down.

It was just a thought.

(:-})

[Sbikerbud]

Car jump leads are the only thick cable i have lying around........my cookers gas

Babysitter, the intermediate gear thing sounds interesting/plausible. I didn't know there was an intermediate gear but i was heading along the same lines when i suggested the starter clutch may be getting 'tight'. If the solenoid bypass doesn't work i may look into the gear thing.....can you remember how much it cost you and how hard it was to change?

Sirch345, all connections cleaned, vaseline'd (ooer missus) and done up nice n tight with socket

Wicky, changed the starter motor for a second hand CBR6 unit from Ebay, possible i got another duff example but unlikely

[sirch345]

Sirch345, all connections cleaned, vaseline'd (ooer missus) and done up nice n tight with socket

That's good, and all done properly well done.

Chris.

[tony.mon]

To replace the intermediate gears:

You need to remove the starter motor itself, the alternator cover and you then have to remove the alternator rotor and sprag clutch. You'll need an extractor to get the alternator off. I found that a MAN wheel bolt will fit the thread size and do the job for pennies, if you don't have an extractor.

The spindle holding the transfer gear in place just slides into the cases, and can be removed using a magnet.
Then wiggle the gear set out, and insert a new or known good one.

That's the method Haynes recommends, but I'm sure I've managed to replace the intermediate gears without removing the alternator or sprag clutch before.
The intermediate gear can be (just barely) fitted by removing the lower front cylinder cam chain tensioner blade (the rearmost one on the front cylinder), you need a star socket to do this, but Halfords carry 12 pointers which will do at a pinch.
This means removing the front cylinder CCT, so the engine will need to be in the correct position to do this.
If you're not familiar with fitting cct's then removing the rotor and sprag clutch is less likely to go wrong.

My way's quicker, though!

[AMCQ46]

but a failed intermediate gear will have different symptoms, there should be a noise from the starter as it will be spinning, and I assume a noise from the slipping gear.

on mine it is dead quiet, but as the spedo LCD goes blank it is clear that there is current being drawn and the voltage is dropping, then 30 sec later it cranks and fires OK. hence I think the starter is stalled [brushes or bearings]