Topic: What's the most common cause of a weak starter?

[juntjoo]

My battery has 12v. I don't have a hydrometer yet but could it still be the be the battery? I've charged it plenty. About 24 hours ago it cranked the engine over just fine til it just didn't. Now it's pretty weak.

Should I get a hydrometer to further test the battery or or take out the starter and start with the diagnostics outlined in the book for that? The battery is maybe a couple years old but not in miles on the bike. Perhaps in revolutions of the starter as I've spent a considerable amount of time trying to start the bike since I've had the battery.

Thoughts?

[Stev-o]

The most common casu of a weak starter is a weak battery!

If your battery is a couple years old and not used regularly, it’s prolly past it’s service life.

I don’t know anyone that uses a hydrometer anymore, call your local auto store and ask if they can test it under a load. 

[juntjoo]

The most common casu of a weak starter is a weak battery!

If your battery is a couple years old and not used regularly, it’s prolly past it’s service life.

I don’t know anyone that uses a hydrometer anymore, call your local auto store and ask if they can test it under a load.

Thanks. And having a good measured 12v don't mean nuttin right?

I just don't wanna install a new one and not be able to return it

[Deltarider]

Two rules of thumb that will safe you a trip to a battery tester.
a) Left alone for a couple of hours after being charged, a (still) usable battery will show a voltage of 12,6 V or more. A voltage lower than that indicates the battery is reaching its end.
b) During cranking voltage should not drop below say 10 Volts.

[juntjoo]

Two rules of thumb that will safe you a trip to a battery tester.
a) Left alone for a couple of hours after being charged, a (still) usable battery will show a voltage of 12,6 V or more. A voltage lower than that indicates the battery is reaching its end.
b) During cranking voltage should not drop below say 10 Volts.

Ah okay. So 12 isn't good then. I'll recharge then test again.

[wolf550]

had the same problem with my bike. showed 12.4v would start and run. then the cold set in and the battery will only charve to 12v. only a couple years old  and its the fillable one. switch to sealed and the my bike works great

[Jerry Rxman Griffin aka MuthaF'er]

As Steve-O says, take it in for a load test after a proper charge and as Wolf says, get a sealed AGM battery

[Bodi]

You can jump to a car, just BE SURE! polarity is correct. If it starts super well, battery is bad. No change... could be wiring (usually the negative cable connection to frame and engine), solenoid relay contacts need dressing, or - rarely - a bad starter motor probably worn brushes or carboned up commutator.
Measuring battery voltage when starting tells a lot, but a battery that only has 12V after charging and a 10 minute rest is on life support.

[PeWe]

Make sure that the thick battery ground cable has good contact with frame and engine casing. I grinded frame and case contact points under the cable ear fastened by hanger bolt. Used vaseline to avoid corrosion.

[rotortiller]

If the starter is weak I'd look at the brushes, commutator, windings, and bearings. Now if it's something else causing a strong starter to under perform; look at battery, battery/starter connections and the main ground. If the engine is partially seized or has higher than normal friction all that other good stuff won't matter LOL.

[juntjoo]

If the starter is weak I'd look at the brushes, commutator, windings, and bearings. Now if it's something else causing a strong starter to under perform; look at battery, battery/starter connections and the main ground. If the engine is partially seized or has higher than normal friction all that other good stuff won't matter LOL.

What do you think of this? Does it sound normal?

[rotortiller]

Look at the motorcycle battery voltage while cranking it. The wires on the battery on the floor look to light duty if you expect it to power the starter.

[Stev-o]

Does it sound normal?

No.  And you need to work on your video skills! Pan slowly...

[RAFster122s]

Another item if battery tests good is power wire from battery to starter solenoid to starter could have issues, but not usually fine one day and not the next.

The CX500 I believe shares the same starter or very similar starter design, electrically same...mounting may be slightly different.  A problem many whom have starter issues or less than very strong starters is for them tp put a small ground strap from endbell that holds the brushes of starter to the case of the starter. You will never see any physical signs like hearing or spotting any arcing, but the inability to have a good electrical connection between end bell and starter body causes the starter to exhibit weaker or slower turning starter. Simple fix when cleaning the carbon out of the starter and or installing new brushes.  Cleaning the starter and drop of lube on endbell bushings for shaft is a good maintenance to perform every 2-3 years depending upon how many miles you ride a year.

[juntjoo]

Another item if battery tests good is power wire from battery to starter solenoid to starter could have issues, but not usually fine one day and not the next.

The CX500 I believe shares the same starter or very similar starter design, electrically same...mounting may be slightly different.  A problem many whom have starter issues or less than very strong starters is for them tp put a small ground strap from endbell that holds the brushes of starter to the case of the starter. You will never see any physical signs like hearing or spotting any arcing, but the inability to have a good electrical connection between end bell and starter body causes the starter to exhibit weaker or slower turning starter. Simple fix when cleaning the carbon out of the starter and or installing new brushes.  Cleaning the starter and drop of lube on endbell bushings for shaft is a good maintenance to perform every 2-3 years depending upon how many miles you ride a year.

Thanks. This bike only has 8k miles. Seems unlikely I should have these issues no? I just pulled out the starter and it looks new. I'll give your suggestion a shot though.

Anyone know if I should be able to pull this cable connection off as the book suggests? Seems really stuck on there.

And my battery cables look fine no? I never loosened them.

My truck battery starts my truck just fine and still wasn't able to turn my bike engine over at a normal speed. Check YouTube vid above.

To me I hear something funny in there. Steve-o says no though. Any other opinions?

Thanks!

[juntjoo]

I don't see how these could be bad connections. I never loosened them. Would it still be a good idea to take them off and put a wire brush on a dremel to them?

[juntjoo]

Does it sound normal?

No.  And you need to work on your video skills! Pan slowly...

Oh, you said "no" meaning you in fact agree it doesn't sound normal correct? You hear that little strain underneath the regular sound? What do you think that is? I had been cranking it over a lot recently trying to get it started then suddenly it got real weak.

[RAFster122s]

Definitely not normal. Put set of jumper cables between batteries

And later throw charger on your bike's battery to make sure the charger think it is fully charged too! 

Just never use a running car to jump start a bike. The car could be damaged and the bike usually is as car's electric system can overpower a bike's charging system and fry things.

Something is wrong either in starter circuit or wiring or starter if you can turn or kick start the motor over without those super tight spots that the bike's starter is struggling to try to overcome.
So, see if you can slowly kick it through and see how it feels doing it with your arm. If you don't feel major major resistance doing that, then it is either wiring or starter or other starter system...

If you pull the starter you can bolt it to a board you can stand on to keep it from torquing out of control when you test it to see how it sounds and works when you put battery voltage across it.
Taking it apart and cleaning any carbon and other muck out of the starter is good preventative maintenance and should be done every couple years.
Simplicity riding mowers recommend starters be cleaned yearly.
Don't remove the starter's grease unless you replace it if it is dirty, just don't put more on it than it had or you can cause more issues...

[Don R]

 These are all at least 40 years old, the start relay can be burned, there are posts about taking them apart and cleaning the contacts, Battery cables can be weak, check for hot spots after cranking. Could the carbs be leaking through? Gas in a couple cylinders can make it hard to crank. I'd pull the plugs and spin it.

[RAFster122s]

Well you can jumper the relay/solenoid with a heavy wire momentarily to bypass the relay, right? Or a screwdriver you don't like, it is going to pit and likely leave a scorch mark where you short it...
Yes, wiring can sometimes develop black wire rot inside insulation. Hot spots would indicate rot or break.

[Alan F.]

I'll second trying to crank it with all 4 plugs out and the kill switch off.

[Don R]

 Another thought is, excessive cranking without a cool down period can overheat a low mile and otherwise good starter motor causing open circuits in the windings.   

[HondaMan]

Ben: sorry if I missed this, but...did you test the voltage at the starter side of the Start solenoid while cranking? This is what DonR is getting at. The contacts inside the relay can be burnt a bit, and then after sitting a long time they corrode. The solenoid comes apart so you can clean off the little shorting bar (or some can just be flipped over to the unused side). Lightly snad off the copper bolt head contacts, too. A drop of oil (not WD40) will also help the solenoid plunger move more fully: it could also be suffering restricted movement from gunk built up in its tube.

[juntjoo]

Thank you all  I glanced over all your replies and it's a ton of great info. Have just a couple little hurdles though before I can get back to first hand cranking it, then I'll start with all your suggestions. Now gotta find misplaced rotor bolt and furnish a replacement for the little index pin on the back of the ignition advance unit that keeps sinking in too deep...

[juntjoo]

Just wanted to post this real quick. It might not be necessary by the time I get back. I'll be moving down all of your suggestions after posting this. I'm hand turning over the engine and it's squeaky. Doesn't feel difficult though the noise indicates to me some incorrect friction. It's short if you got a moment, thanks

This is with starter detached. I'm about to check the starter operation on it's own...