ST1100 No spark!

[essara]

Hi everyone,
New to the forum here. I just picked up a beautiful 1992 ST1100 with 31,000 miles on it. Other than some minor cosmetic damage the bike looks very clean and in good shape.
When I picked up the bike it was running but had a bad battery. When I got the bike home I put the battery on the charger and washed the bike. I used a pressure washer and the left side cover was off. Once clean I dried the bike with the blower. I put the battery back in and found it was dead. I then jumped the bike with my truck (running) and the bike would crank but wouldn't start.
I pulled a plug and found no spark; I confirmed that the other cylinders also had no spark.

So far I have tested the following and they all seem to be working fine..
-kill switch
-side stand switch
-neutral switch
-BAS bank angle sensor
-secondary resistance on ignition coil
-clutch safety switch
-checked all fuses

I also noticed the red wire bypass has not been done but there is no sign of excessive heat or corrosion or damage of any kind.

I am at a loss at this point. I ordered a new set of plugs with for the distant chance that they are fouled. I think the next step I will take is to remove the forward cowlings and do the full tests on the ignition coils and the pulse generator coils. I will also inspect the wiring harness carefully for faults.
Any input anyone has would be very welcome! The bike was running when I picked it up hours earlier so logic says it has to be something I did when I got it home.

Andrew.

 

[Uncle Phil]

I would start simple - Get a new battery and make sure your connections are good.

 

[essara]

100%, I have installed a new battery. I'll dig into the harness more tonight. With any luck it will be something simple, Thanks.

 

[tt48]

I would try to start it with the new battery before you dig into the harness. It could be that the old battery did not have adequate amperage to drive the ignition coils.

 

[mortenk]

Beautiful bike - congrats! It doesn't sound like the battery as you already tried with a car battery. If it cranks well, battery is typically OK, so you have to dig in. Since it happened after using a pressure washer, I am thinking water is the culprit...

 

[Uncle Phil]

If it was running before, then water got into something and probably created a short.
I never use a pressure washer on my ST1100s because it can force water in where it does not belong!
You might also spray some contact cleaner into the ignition switch and kill switch just for grins.
Beware if you remove the upper fairings there is a fairing bolt stuck way up beside the headlight that is hard to see and hard to get to.
You think you have everything loosen and you will crack the fairings if you don't remove those (one on each side).
Once I get them out, I never put them back and it works just fine.

 

[essara]

You are right about the pressure washer. I come from an offroad background where the pressure washer is your best friend..haha. I'll be sure to avoid it in the future, I'm definitely kicking myself for that one. Thanks for the tip on the fairing!

 

[SMSW]

As Phil said, never ever use a pressure washer. You can force water into bearings and past seals with an inadvertent sweep of the wand.

If you have no spark at all (meaning in none of the 4 cylinders) then your problem is upstream - juice is not getting to the coils (plural). One coil could be bad, but all 4 at the same time suggests an electrical problem elsewhere.

Edit, just saw your comment about the pressure washer - ignore mine.

 

[red one]

Nothing stronger than a garden hose.

 

[essara]

100% agree, no way all the coils are bad if there is no spark anywhere. I have the wiring diagram so Will try to isolate which part off the system is not getting signal for ignition tonight. Thanks for all the suggestions.

 

[essara]

Ive traced the ignition circuit in green. I think i'll start at the coils tonight and trace back untill I find the problem.

 

[red one]

100% agree, no way all the coils are bad if there is no spark anywhere. I have the wiring diagram so Will try to isolate which part off the system is not getting signal for ignition tonight. Thanks for all the suggestions.

Don't forget the fuses. If you have an multimeter check them for continuity.

 

[essara]

Don't forget the fuses. If you have an multimeter check them for continuity.

Right that makes sense!

 

[Al st1100]

water inside the kill switch??

 

[essara]

water inside the kill switch??

Seems to be ok,, I checked it with the multimeter. Maybe ill take some compressed air to it anyway to be safe.

 

[Bmacleod]

Be sure and check the plug from the ignition pulse generator and make sure it didn't get damp inside

 

[Phyer Phyter]

You say no spark and then go on to say that you'll replace the spark plugs incase its them. So I am not sure that you have a spark problem?
Chances are that you just pressure washed your bike you may have got something wet and need to start checking wiring connections are clean, dry and tight.
For an engine to run you need spark, timing and fuel. I will assume that engine timing is fine (timing belt etc)
With the ignition on - toggle the engine kill switch, do you hear the fuel pump run for about 2-3 seconds when kill switch move to on/run? You will hear a slight hum/buzz when it does. IF you hear nothing then you need to dig deeper into the fuel pump operation. Do you have power at the pump wiith the ign on? IF not you need to dig into the electrical to the pump, fuse, connections, and so on. IF you do hear the pump cycle then you need to confirm that fuel is getting to the carbs, plugged fuel filter? Pinched fuel line? There's a fuel diaphragm that I've read about here that can fail and people have bypassed it with out further issues.
Do you have spark? Pull a spark plug wire off, stuff a new spark plug in the wire and turn the motor over, do you see a spark jump at the bottom of the spark plug? If yes you have spark, if no then you need to dig into why there's no spark. Are the plug wires good? any signs of tracking or arcing anywhere along the wires, have they rubbed through somewhere?

These are things to look at and to look for..... Let us know what you find out.
Edit/. I just re-read your post about no spark on any cylinder. IS there power on the pos side of the ign coil?

 

[essara]

Be sure and check the plug from the ignition pulse generator and make sure it didn't get damp inside

I tested the pulse generator last night and found that it was reading open circuit. It is supposed to have between 405 to 495 ohms. Tonight I will pull it out and see if there is a broken wire or if the pulse generator is bad.

 

[essara]

You say no spark and then go on to say that you'll replace the spark plugs incase its them. So I am not sure that you have a spark problem?
Chances are that you just pressure washed your bike you may have got something wet and need to start checking wiring connections are clean, dry and tight.
For an engine to run you need spark, timing and fuel. I will assume that engine timing is fine (timing belt etc)
With the ignition on - toggle the engine kill switch, do you hear the fuel pump run for about 2-3 seconds when kill switch move to on/run? You will hear a slight hum/buzz when it does. IF you hear nothing then you need to dig deeper into the fuel pump operation. Do you have power at the pump wiith the ign on? IF not you need to dig into the electrical to the pump, fuse, connections, and so on. IF you do hear the pump cycle then you need to confirm that fuel is getting to the carbs, plugged fuel filter? Pinched fuel line? There's a fuel diaphragm that I've read about here that can fail and people have bypassed it with out further issues.
Do you have spark? Pull a spark plug wire off, stuff a new spark plug in the wire and turn the motor over, do you see a spark jump at the bottom of the spark plug? If yes you have spark, if no then you need to dig into why there's no spark. Are the plug wires good? any signs of tracking or arcing anywhere along the wires, have they rubbed through somewhere?

These are things to look at and to look for..... Let us know what you find out.
Edit/. I just re-read your post about no spark on any cylinder. IS there power on the pos side of the ign coil?

As it stands There is no spark on any cylinder. I checked the coils last night and they check out there is also twelve volts at the imput. I have removed every connector I can access cleaned and dried the (no moisture found) including the PCM. The fuel pump is coming on and when I pull a plug and crank the engine you can smell the fuel vapour coming out of the cylinder. All fusses are good. To be honest the pulse generator coil is the first thing I have found that does not meet resistance values per the service manual. I will dig into it tonight and see if perhaps there is a brocken wire somewhere.

 

[schlep1967]

Somebody get John O. He probably has the answer.