If you measured infinity resistance to ground at pin 3 and 4 with the connector connected in post # 43 it's something wrong with your ignition ECU.

I was testing at the female connector, everything else hooked up, with ignition off. How do i test while connected?

Also, thanks a lot for putting up with me and my inability to ask good questions.

By removing the rear cover from the connector.

Okay, okay, I get this. We must connect in parallel, rather than series.

So when I measure resistance- from pin to battery ground? When I measure voltage- same?

And when is ignition on- always?

FissionMailed wrote:And when is ignition on- always?

Not when measuring resistance.

Here's some new info. Was not able to test with the starter due to me doing this at night on the street, but I can definitely test that when I'm off tomorrow.

Battery: 12.16V (which is low, must not have charged it enough)
Pin #1: .6ohm
2: 10.45v
3: .7ohm
4: .8ohm
7, ignition on: 10.8v
10: 10.9v


Is that voltage drop normal?

Your battery is discharged.  You need to put it on a charger that will give it at least 13.8v.  You need to charge at 2 amps for about 12 hours, maybe more.   

If it has been sitting without a full charge for any length of time(like a couple weeks or more) there is a pretty good chance it has been damaged and will no longer hold a full charge.  I would take the battery out and take it someplace where you can have a load test done. Either an automotive electrical shop or one of the auto parts places like Auto Zone.   Just checking the voltage on the terminals without loading the battery only tells you how much charge is on the plates.  It tells you nothing about the battery's ability to put out the current necessary to start the bike.  A load test measures the ability to start the bike.

Just a little hijack on the same subject - fuel pumps.
I have two RTs. On the 84 the fuel pump is completely silent but works because the bike goes. On the 88 bike the pump emits a constant whirr. It goes as well. So which is normal? Should I be worried about the noisy 88 bike or is it all OK?

My 92LT fuel pump was silent. The 84RT fuel pump you can hear a mile away. Both worked fine.....But I wonder has it to do with the mounting and resonance?

I have found that if the mounting rubber is hard then you get noise.

OK, I wont worry about it hijack over.

So the battery hasn't really been dead- it needed charge, yes, but was certainly strong enough to start the bike. My question remains the same- is the voltage drop demonstrated earlier normal?

FissionMailed wrote:So the battery hasn't really been dead- it needed charge, yes, but was certainly strong enough to start the bike. My question remains the same- is the voltage drop demonstrated earlier normal?

Refer back to .75's post #57
Just because the battery can turn the starter over doesn't mean its got a good charge. Cranking the starter with a depleted battery can damage your starter relay contacts. A poor battery can also overload the alternator while the engine is running and possibly stress out other electical components on your bike.
If your bat won't hold a charge it's Kaput... get it tested
12.1v is no where near any good

There's a distinct possibility that your running problems maybe caused by a dud battery.
In anycase, it's certainly very difficult to troubleshoot an electrical fault with an underperforming battery.

Kaptain Holister wrote:
12.1v is no where near any good

A fully charged lead acid battery has a static voltage of 12.8v and at no charge will show 11.8v.  At 12.1v your battery is at 30% capacity, and worse, is doing irreparable damage to the plates if not recharged immediately.  Sitting at a low charge at this time of year is hard on a battery.  I suspect you are well past the point of no return on this battery.

As the Kapt. mentioned, trying to start with such a low charge will damage the starter relay, and possibly the starter further adding to the final cost of getting things running.

The voltage drop seems a bit more than normal, I would suspect the kill switch.
Measure the voltage before and after the kill switch at the RHS switch assy
under the tank.
But this voltage drop isn't neceserrily related to your start problems.

OK, after the battery issue is solved...

Assuming all readings into the ignition module are good, we're looking at that being the problem, right?

Moving on from that...How exactly is the injection unit tested? I see there are ways of testing resistance on a few pins, but I'm not sure how to test with it connected. Is testing the ECU more of a case of "everything else is good, this is bad"?

To throw some more fuel into the fire..... .
When you push the start button the mixture is enriched.
Could be that the mixture is all to lean, caused by a wrong sensor signal.
Just a thought..........

Air flow meter and temp sensor are the only sensors that control air fuel ratio, correct?

And air temp sensor.

FissionMailed wrote:...How exactly is the injection unit tested? I see there are ways of testing resistance on a few pins, but I'm not sure how to test with it connected. Is testing the ECU more of a case of "everything else is good, this is bad"?

other than testing continuity or impedance on the ecu plug pins back to connectors/switches/sensors, about the only thing you can do is swap it with a good'n. Don't use your m/meter on the unit itself. imo its unlike to be the ecu... but I have one for sale AU$95. Postage to the US may be a bit high.
I bought it to swap my ecu when my engine was stalling. Turned out exhaust valve clearances were way too tight.

You've not confirmed if your starter relay is working/replaced?? They are a common problem.

Well, here's the starter relay. I don't know how to clean this, or if anything looks bad.

https://i.servimg.com/u/f38/19/15/72/20/20150310.jpg

I immediately take that back. One of the contacts came off, I think. This repairable at all? Could this actually cause the issue?



https://i.servimg.com/u/f38/19/15/72/20/20150311.jpg

While it probably can be repaired, I'd not like to trust that the repair would last. I'd replace it.

Bill

I'd say its Kaput. That contact is very burnt. Probably caused by a bad battery (even tho its cranking your starter). Can't see the condition of the other contact in your photo but if its ok or you can clean it up with some fine emery paper you may get away with it for a while. But I'd be replacing it.
See my post #32 which has a link to euromotoelectric.

EDIT: That loose contact may have been shorting causing the problem. Try applying 12v to the small connectors (not the big ones) and see if the remaining contact closes and opens. If it works put it back in and see if you have a fix. but I'm thinking while it may be related its not the cause.

The contact is burnt probably due to a low/dud battery. Have you properly checked your battery under load yet? This could be the cause of your problem.

I'd say replace the relay.  You would have to manufacture a new contact from the proper material and have a means of rivetting it back onto the armature.  Cheaper to buy new.  Try these people if you're in the US, in addition to Beemer Boneyard and Euromotoelectrics.

That burned-looking area doesn't appear too bad to my eyes- the black parts wipe right off with a finger.

I have no idea where that contact fell off of, which is making me hesitant to reinstall the relay.

When I have a new relay, or reinstall this one, I'll load test the battery.

Side note: never opened up a relay, man, learning a lot here. Immediately understood how relays really work

They will work with just one contact provided the burnt contact is well clear and the other is in good condition, but I certainly wouldn't be leaving it in there for too long, just to get you going till you get a new one. However, it seems you're not too sure about what's happening inside that relay so best to bin it.

Buy a new one imo as they now make them with diodes which protects your electronics from 'back emf' from the relay coil. If you buy an older secondhand one you also run the risk of getting a similarly damaged relay. New from Euromotoelectrics are cheaper than some of the secondhand ones I've seen on ebay.

Make sure your battery is properly tested and good before installing the new relay.

Yeah, it was half a contact burned off. Been busy lately-just ordered a new starter relay from euro moto electric, got a new battery shipping over (decided to as my old battery was a little short on CCAs-not bad, per se, just not the correct strength for my bike). Will continue diagnosis after I get all that stuff installed.

The K100 requires a min 28a/h with 360cca battery

Would also like to order pintle caps/screens/o-rings for the injectors- which Mr. Injector kit is the proper one? Or eBay link...thanks again for the help.

I actually never noticed this before, as the bike worked fine for a year... But what are the consequences of running a too-small battery? This old one is actually 18Ah, no CCA listed.

if we had a 600 watt starter motor
for every 3/4 volt drop below 12.5  (12.5 - .75 = 11.75 volts ) the cranking amps will be more than at the higher voltage

now if the load at cranking was say 48 amps at 12.5 volts (600/12.5=48)

 it could be 51 amps at 11.75 volts (600/11.75=51)

but that is a direct rating for turning the motor without too much load of 600 watts (a bit under 1 horsepower = 770 watts round about )

the real peak load could well be  the current squared .... 


48*48= 2304 peak crank amps/12.5 volts  = 184.3 crank amps for 12.5
51*51= 2601 peak crank amps/11.75 volts = 221.3 crank amps for 11.75
which is a pretty high percentage above the lower figure


if the relay was only rated for 50 amps (200 peak)  for arguments sake ...  some welding is going to happen at some time ...not necessarily all at once, but will depreciate the contact area of the relay by some small amount from the slight weld-blast event ... it wont take long for the contact current rating to be reduced as a regular event to when the contact points  become too hot to handle the current path through the dissimilar metals then become dewelded ....sound familiar ?

I had to read it twice (because I'm getting old... and its late at night).... but great explanation charlie.

In laymans terms... you fry your starter relay and possibly your alternator and starter motor components as well.

FissionMailed wrote:Would also like to order pintle caps/screens/o-rings for the injectors- which Mr. Injector kit is the proper one? Or eBay link...thanks again for the help.

The Fuel Miser ISK-0500AX (contains a set of 2) is the kit I used.
EDIT: I think Fuel Miser are only in Oz
.... but I'm sure any kit for an EV1 type injector would be ok.

A little more to add to Charlie's excellent post. 

Starting motor will have two current draws on the battery.  The first is the inrush current.  This is the current that is drawn at the instant you depress the start button.  Inrush is simply the battery voltage divided by the motor winding resistance.  The winding resistance is so low it looks like a dead short to the battery.  The inrush is going to be pretty much equal to the cold cranking amps (CCA) rating of the battery.  For our bikes that is around 380 amps.

Inrush current will create a huge amount of instantaneous torque to overcome the inertia of the motor and the engine it is starting.  A millisecond after the button is pushed the motor is turning and cranking the engine.  At this point, the motor is also acting as a generator, making what is called "Counter EMF".  EMF stands for Electromotive Force.  This counter EMF pushes back against the battery voltage and by doing so reduces the amount of current to the motor to the 48 amps that gives the 600 watt rating.

This happens every time you hit the starter button, and as long as the motor is able to spin the engine, all is well.  The problem is when the inrush isn't enough to overcome the inertia.  Then the start motor doesn't spin, and since no counter EMF is generated, the full current output of the battery just keeps flowing through the motor and the wiring of the starter circuit.  Since electrical power is the current squared times the resistance it is flowing through it is easy to see that huge amounts of watts are being created as heat everywhere there is the slightest amount of resistance.

For sake of an example, let's say that the battery is weak and can only supply 200 amps of inrush, and that isn't enough to get things moving.  200 squared is 40,000.  Multiply this by even .01 ohms of resistance and you still have 400 watts of power being dissipated as heat.  Put 400 watts into less than a gram of metal in the start relay contact points and it will only take a couple milliseconds to melt the points and weld them shut.  

As long as the starter motor can spin and the current drops to the 48 amps the power is only 48 squared or 2304 times that .01 ohms in the start relay or a very manageable 23 watts. 

One additional, and unrelated point is that when the engine is being started it is basically an air compressor.  To minimize the load on the starter motor, minimize the amount of air being compressed.  With a weak battery it is very important to leave the throttle closed to make the engine as easy as possible to turn over.  This is one advantage to fuel injection in that even with low air flow rates, we still get a good charge of atomized fuel to get things going.

You guys are VERY good at explaining things. My starter relay has been installed. Just waiting on my battery to get here...can't wait to see what other parts I need.

Is there any reason why my new battery would be showing only 1.5V? Testing the old one still yields 12.5. It came from BatteryStuff.com and they're saying it should be precharged...

They are usually stored (and sendt) in a dry condition, have you filled acid on your new battery?
After that it needs 2-3 hours on a charger to reach its full capacity.

If it's a ordinary lead/acid type.

AGM battery, nothing to fill up.

This is unbelievable. I can't even charge it because it's so dead. My 6A charger won't turn on.

Sounds like dead short in several of the cells. Get a replacement battery from the supplier.

What brand/model is it?

Scorpion SYIX30L

Not an inexpensive battery, honestly. $104

Edit: and now showing 8.6v. What on earth?

Sounds weird.
Did you test it out of the box or is it installed in the bike?
What ever you do don't try to crank with that bat. They must have a full charge when installed.
I wouldn't put it on a charger unless your supplier says so and don't even think about trying to charge it up from the bike's alternator.

Looks like a good bat tho and the price is pretty good too. I couldn't find any negative comments about it... except one guy complained because "it only came in one colour"
Looks like you just got a dud.

Tested out of the box, have not installed. Not taking a chance on tearing up a brand new starter relay.

Sounds like a bad battery.  They should have a full charge out of the box.  I would think you should be able to return for a warranty replacement.

I have two of the Scorpion AGM batteries in my bikes and they work really well.  One is a year old and has 8500 miles on it.  The second is about 5 months old and has been in the bike over winter storage and has started the engine flawlessly every two weeks in temperatures down to 10 degrees F.  For the price I think they are a great deal even if they were made in China.

Hopefully customer service will be able to send me a new battery quickly. I'm dying without this bike.

Question: is it a good idea to pull the fuel rail, throw some cardboard down, and test the injectors that way? I still keep thinking fuel issue for some reason. The pump runs after I let go of the starter for 1.5sec, I've visually verified spark on all 4 cylinders, but I haven't checked to see if the injectors are opening.

Edit: alternately, I can throw a 12v led on each injector connector, right?

:suspect: How are you going to fire them up to test the flow or the signal? The motor needs to turn for the injectors to get a signal afaik. Both your bats are dead and you wouldn't want to risk frying your new starter relay using your old battery to crank her over??

Best to wait for the new battery and take one thing at a time. Otherwise you have no idea what the fix was or could end up with another problem.

It's more likely your injectors are ok imo. They're a highly reliable component unless the machine has been badly neglected (they can't tolerate water in the fuel for too long).

Anyway, better to take them out and bench test, clean and install new kits. Its much safer, easy to do and cheap, or get them cleaned professionally with new kits for about $30 each, but do it after the new bat goes in!!

Was thinking I would install the bad battery that's holding about 12.5V and manually turn the rear wheel with the bike in gear, checking the injector connectors for a pulse. Or pull the fuel rail and do the same. Bad idea?

I guess I am just thinking the battery won't fully solve the issue- thinking it's only coincidence that the battery died, since I left it almost dead for a week or two. That plus..the battery died while the bike was idling? The bike was running when this issue started

I'll hold off until the new battery arrives.

And yeah, the problem started when the bike was idling. I was letting it warm up after work, it ran for a few minutes, had an odd change in the way it ran, and at that time no longer went over 2k rpm, cutting out and dying when you tried to. This was repeatable every time until I changed spark plugs, at which point it no longer idled.

Just a quick note: I called BatteryStuff, they answered (not a call center), and they are shipping me a new battery today. They didn't even want the bum one back, just asked that I recycle it somewhere. Should be here before the weekend.