Slow start - no hot start

[John d]

I suspect I'm in need of a new or rebuilt starter motor.

The bike starts a fair bit slower when cold. When hot, on a really hot day, like yesterday, it wouldn't start after gassing up. This has happened before this year under the same conditions so I ended up buying a brand new Yuasa battery. It did start yesterday after a few minutes by holding the throttle full open and it just managed a start. The battery is not the problem and has a resting voltage of 13.06. Bike is a 2008 with 94,500 miles.

I want to check the current draw while starting with a 200/1000 amp clamp on meter I had bought new years ago, but never used.

Question. Where would I use the clamp on meter without taking too much apart? It's stinkin' hot and humid in the garage, but I want to get going on it.

[ionbeam]

...I want to check the current draw while starting with a 200/1000 amp clamp on meter...Where would I use the clamp on meter without taking too much apart? It's stinkin' hot and humid in the garage...

Either the red or black battery cable will probably be the easiest and best location. If your amp meter has a 'Peak Hold' button, now would be the time to press it. It will lock the highest reading so that you can easily see what the value was after cranking. If not, you will need to watch the reading which will flicker and try to see if it exceeds 80 amps.

[FJRoss]

I ASSume it is a DC clamp-on meter? (The AC ones are more common and cheaper than AC/DC)

Good luck with diagnosis and fix. Are you going to clean up yours and replace o-ring seal + brushes or buy new/refurbished one?

[John d]

I ASSume it is a DC clamp-on meter? (The AC ones are more common and cheaper than AC/DC)

Good luck with diagnosis and fix. Are you going to clean up yours and replace o-ring seal + brushes or buy new/refurbished one?

Apparently it's AC only but has DC volts. I got readings of 12 16 and 33 amps. Not sure what that means now with the AC amp tester.

[philharmonic]

Easy for me to say, but looks like you need a starter motor. My 03 got the same way at about 75,000 miles, Would start OK when cold, but not real fast. But barely turn over when hot, and it got so bad it would pull enough amps that it would draw the battery down below 10.5 volts and the mileage and clock would reset. I sold the bike with the understanding that the starter was slow, and bought an 07. There is a thread on one of these FJR forums right now about a guy who claims to change the starter in 45 minutes or so. Good luck, Phil

[ionbeam]

I ASSume it is a DC clamp-on meter? ...

Apparently it's AC only but has DC volts. I got readings of 12 16 and 33 amps. Not sure what that means now with the AC amp tester.

AC amps means nothing. You need to have a DC meter to get a real reading.

[wheatonFJR]

All I know about amps is that you want big ones if yer in a rock band. Good luck John!

[John d]

I ASSume it is a DC clamp-on meter? ...

Apparently it's AC only but has DC volts. I got readings of 12 16 and 33 amps. Not sure what that means now with the AC amp tester.

AC amps means nothing. You need to have a DC meter to get a real reading.

Thanks. I'll have to get hold of a DC meter. Obviously I'm not to swift with the electrical stuff.

[ionbeam]

Do you have a DC volt meter? Some DC current probes have their own built-in meter but they aren't common and they are often confusing to use. Some DC current probes plug into the jacks on a DC meter and you read the current off the DC meter.

One type of DC amp probe is shown below, it is the type that plugs into a volt meter. The reading on the volt meter shows the amps being used by my '04 FJR at idle with no accessories on. This probe was ~$70 USD. The meter is showing a negative number because: I had the probe clipped on reversed to show the controls in the picture. It doesn't matter which way the probe is clipped on over the wire, the reading will be the same. The amp probe was clamped onto the red wire leaving the RR and going to the battery, I could just maneuver the probe to catch the wire.

[John d]

Do you have a DC volt meter? Some DC current probes have their own built-in meter but they aren't common and they are often confusing to use. Some DC current probes plug into the jacks on a DC meter and you read the current off the DC meter.

One type of DC amp probe is shown below, it is the type that plugs into a volt meter. The reading on the volt meter shows the amps being used by my '04 FJR at idle with no accessories on. This probe was ~$70 USD. The meter is showing a negative number because: I had the probe clipped on reversed to show the controls in the picture. It doesn't matter which way the probe is clipped on over the wire, the reading will be the same. The amp probe was clamped onto the red wire leaving the RR and going to the battery, I could just maneuver the probe to catch the wire.

Thanks, but mine only goes up to 10 amps DC.

[ionbeam]

Thanks, but mine only goes up to 10 amps DC.

No, no, no The green amp probe puts out a DC voltage which is proportional to the DC current and read on the DMM: example, clamp the probe around a wire that is carrying 10 amps, the green amp probe puts out 100mV which you read on the DC DMM as 100mV which is the current divided by 100. Put the probe around a wire carrying 110 amps and the meter will read 1.1 volts. Put the probe around a wire carrying 250 amps and the green probe will send 2.5 volts to the meter.

Using this kind of green amp probe plugged into your DMM and clamped around the red battery lead and with the starter motor drawing 140 amps (a bad starter reading) the DMM would read 1.4 volts. If the starter is good and drawing 70 amps the meter would read 0.7 volts.

Where is that confused smilie when you need one

[bill lumberg]

My bmw mechanic and I chased a sort of similar problem for a while. It had to be electrical. Turned out to be the charcoal canister had shipped welding pudding to the fuel filter, which, in turn, caused the fuel pump to blow its crimp. It was awesome.

[FJRoss]

This looks OK for $50
https://www.amazon.com/Protmex-MS2108-V ... lamp+Meter

Edit:
Actually had a better look at the specifications - might not work anyway. While it measures AC and DC amps, apparently the "clamp-on" is only for AC amps although this isn't clear - Maybe DC amps has to be measured "in-circuit"?

[ionbeam]

This looks OK for $50
https://www.amazon.com/Protmex-MS2108-V ... lamp+Meter

In a previous post I mentioned that some amp probes which are 'all in one' meters could be confusing to use, this is the exact one that I had in mind. I have a meter like that and I had a hard time understanding how to use it correctly. Anyone not used to meters and electronics is likely to have a frustrating time or even feel that the meter is broken. Also, the meter is a generic Chinese product which can be found with many different names branded on the same fundamental meter. It does come with a manual. It's written in Chinglish and it useless.

[FJRoss]

Alan, if you are having issues figuring out how to use it then I expect it is one seriously f'd up piece of equipment! Some meters are pretty intuitive in their operation and others may be less so. The clamp-on adapter in your post seems pretty simple.
The only thing I can say about the "Chinglish" manuals (and I have encountered more than a few) is that their English is way better than my Mandarin. For uncomplicated stuff, it is sometimes fun to read them and try to figure out what they meant to say.

[ionbeam]

...The clamp-on adapter in your post seems pretty simple...

$76 USD.

The pic is a clickable link:



Edit to add:

This type meter does measure both AC and DC current. As previously mentioned, the meter comes with various names and various case colors but they all are essentially the same meter inside.

[Cav47]

Can you borrow one of those at AutoZone?

[John d]

The MS2108A you show looks like the ticket.
I ordered the MS2108A by Aimometer. It was in stock at Amazon.ca for 59.99 with free shipping, includes tax .

[John d]

Can you borrow one of those at AutoZone?

We don't have AutoZone in Canada, but thanks anyway.
I just ordered one from Amazon.ca. It's nice to own your own.

[silverback]

If you truly want to diagnose this use voltage drops.

Every circuit must drop volts equal to source voltage. So, if you have a 12 V battery, all the "used up" volts for each component must add up to 12V.

Put the positive voltmeter lead to the positive terminal of the starter and the negative to a known good ground (the negative battery terminal) and hit the starter, it should drop very close to 12V.

Say it drops 11.98V and you've measured the resting battery voltage at 12.01V. That means everything getting to the starter is using 0.3V. not unreasonable.

Say it measures 9.6V and the battery is 12.01V. that means 3.5V is getting used up somewhere other than the starter.

Next...

Check the starter case or a lug to the battery negative. You should see 0V or very close. You don't want any volts used up on the negative side either. Another check is from the positive terminal of the starter to the positive battery terminal. It should read 0V. (Or very close. On a starter circuit, you really don't want much more than 0.5V drop anywhere except the starter)

There are some real advantages to voltage drop checks. First, they don't fry your meter if you exceed the recommended amp rating because you're not making your meter part of the circuit. You're paralleling it. Second, it checks the circuit during operation. It is a "live" reading per se.

Now...if you get the full 12V drop at the starter and close to zero everywhere else, you can bet your union made bib overalls the starter is in need of replacment.

If you find a voltage drop anywhere else, you have a load there (a resistance in the circuit) and it is using up juice the starter needs.

Electricity is usually pretty mystical to everyone because it isnt something you can see and touch. But, it's easy once you figure it out. Just takes some time.

Clear as mud?