Advice needed, engine has packed up

[Joseph]

Right.

This bike can't do this to me, it's my only transportation 

'91 1100

1216

OE ECU, +4 degree advance

Stick coils

RS38 carbs

 

Symptoms : started fine the other day  hadn't seen the road for around 5 weeks.

It started running rough after a few miles, as if it was running out of fuel. It wasn't, but i added fresh fuel to the few liters that were left in it.

That didn't help or hinder.

I tried different (known) stick coils and it started well, but again, similar rough running occured

I checked the plugs on the ECU, i replaced all the spades, some were loose, some were oxidised, but that doesn't seem to have been an issue.

The other day on the way home after filling up it was running badly, but all of a sudden went fine, for about a kilometer then went back into limp mode.

I checked the carb bowls and main jets, but nothing seemed out of order. Checking in the carbs they spray fuel when you open up

Today since i've had more time i checked the spark plugs which are perfect coffee chocolate colour, and all of the coils give a good blue spark when tested on the head with a plug (writing this i realise i didn't do the test with the actual plugs)

Any ideas ? It seems to be getting air fuel and sparks, but now it's packed up it just won't start at all

[TonyGee]

do the simple things first, if you have a spare set of plugs throw them in and see what happens 

[Kamikaze]

check the pick up behind the stator cover and make sure the oil pressure plug is screwed in tight. then if u can swap the ECU.

sounds like an ignition problem.

[Joseph]

Hey.

I will check those @Kamikazebut extra info to add :

After cleaning up the ECU terminals i managed to get a healthy start up/rev/running

Went well just a bit then started playing up.

Let it rest, started it up. I've got 1 and 4 exhaust pipes that are cold.

Changed ECU by another same one but i have the same problem.

[TonyGee]

that could be a pulse coil problem ??  but check the wiring first. 

Edited February 11, 2022 by TonyGee

[Kamikaze]

6 minutes ago, Joseph said:

Hey.

I will check those @Kamikazebut extra info to add :

After cleaning up the ECU terminals i managed to get a healthy start up/rev/running

Went well just a bit then started playing up.

Let it rest, started it up. I've got 1 and 4 exhaust pipes that are cold.

Changed ECU by another same one but i have the same problem.

Ok. Check ur carb balance or sounds like your carb slides are sticking. Or something is causing them to stick once u feed fuel in there. 
 

if u had a spare set of carbs, change them ans see wat happens..

[Gixer1460]

As using original ECU it must be running wasted spark and problem with 1 & 4 ties in with this - I'd trace all the wiring for dodgy contact, frayed or partially shorting wire.

Looking at MJ and accel pumps doesn't help if the idles or emulsion tubes are dirty - 5 weeks storage / E10 fuel / low fuel level / water vapour contamination ? ? ? 

[dupersunc]

The coil for 1&4 is breaking down. Throw away and replace.

[bluedog59]

Before we start looking for big problems, have you checked for a consistent fuel flow  and the tank breather is clear ? If it fires up and runs for a short distance before the problem shows up then I'd route all the carb drains into a can, crack the drain screws open and check fuel flows and keeps flowing. Just a thought. 

[Fazz711]

I'm with Bluedog59 

I had simalar problems in the past and turned out to be fuel restricted by filter. 

Not complete blockage but enough to slow it right down so it felt like running out of fuel 

[TonyGee]

1 hour ago, dupersunc said:

The coil for 1&4 is breaking down. Throw away and replace.

it has 4 stick coils  

[dupersunc]

51 minutes ago, TonyGee said:

it has 4 stick coils  

Glad your paying attention.

Because I'm clearly not.

does point the ignition side though if its 1&4. 

Are the coils set up so the resistance is correct for the ignition module?  If they arent the current draw may be higher and cause the circumstances uit to over heat.

[TonyGee]

10 minutes ago, dupersunc said:

Glad your paying attention.

Because I'm clearly not.

Its a one off, I don't usually pay attention  

[Joseph]

Right !

Thanks for your input.

Flow to the carbs i did doubt, because of the running fine then breaking down / choking out after a seemingly similar distance ridden

However, i do not have a petcock in the tank anymore, and all the lines were changed yesterday.

However it seems like @Gixer1460won the prize again, I tried another stick coil loom i have, and it is now running on all four right away 

Need to wait till day to make a test ride but hopefully thats all it was. 

I made a brand new stick coil loom just now with brand new connectors, the original one that i made was done with a Yamaha item that i cut and soldered so maybe that packed up somewhere beneath the tape wrap ?

I'll keep you posted.

I must say that it did start rather much better also maybe due to the brand new terminals in the ECU plugs ?

[Gixer1460]

Just followed the clues Pal - just followed the clues LOL! But the point above regarding the coil resistances is also valid - low ohm COP's draw a lot more amps and OEM CDI's do struggle with that and can over-heat to the point that output falls away - may be something to bear in mind!

[Danm54]

May be obvious but you've wired the coils in series not parallel right?

[Kamikaze]

glad u got it sorted...best thing bout the old girls is most of the time u can sort it out urself.

Its either fuel, spark or ignition....go knows how they diagnose electrical problems on these new race bikes...

[TonyGee]

4 minutes ago, Kamikaze said:

glad u got it sorted...best thing bout the old girls is most of the time u can sort it out urself.

Its either fuel, spark or ignition....go knows how they diagnose electrical problems on these new race bikes...

one thing that put me off mechanicing on modern bikes, doing a road test on a GSXR1000 with a laptop on my back and plugged into the bike  then start adjusting things on a computer screen !!!!!!  not for me, i like using hand tools   give me a set of carbs any day 

[Joseph]

2 hours ago, Gixer1460 said:

But the point above regarding the coil resistances is also valid - low ohm COP's draw a lot more amps and OEM CDI's do struggle with that and can over-heat to the point that output falls away - may be something to bear in mind!

 

1 hour ago, Danm54 said:

May be obvious but you've wired the coils in series not parallel right?

This COP setup has served me faultlessly for over 5000 km now, on a brand new 100% rebuilt engine

Not exactly an electric engineer i followed several tutorials found online for the wiring diagram, and also selected coils that as per same tutorials gave 1.5 ohm each (OE coils give 3 i think ?) 

So I basically cannot explain the hows and whys i did what i did, but i did follow common sense advice.

This initial COP loom i made however was done by cutting up and resoldering a Yamaha loom, maybe dampness or my shoddy worksmanship or both did something over time ?

I remade a full loom with brand new plugs and uninterrupted new wires, so i'm hoping that will serve me well ?

@Kamikaze: exactly, thats why these OSS are all i use and will ever use, nothing ever fails on them, right ? 

[Kamikaze]

7 minutes ago, Joseph said:

 

@Kamikaze: exactly, thats why these OSS are all i use and will ever use, nothing ever fails on them, right ? 

 

HAHAHAHA....ok ok, sometimes they shit themselves. but with the knowledge on here, there isnt a problem i havnt seen fixed or rectified by advice or self taught experience.

And yes, modern tech parts like stick coils are a great upgrade, stick coils arnt rocket science so we can easily fix or replace them at low cost. but they help the old girls survive dying old parts.

All my 5 girls are over 30 except for the K4 1000,  but your right...i just cant imagine owning a new bike, id go mental if i couldnt work on it myself

[Joseph]

Riiighty

So, somehow, the issue has reappeared.

I rode a total of 75km yesterday, up to approx the 65 mark it went back to running on 2.

I had to keep going like that for around 4-5 till i could stop safely, the engibe stalled obviously.

Had a bit of trouble getting it to start, but, when it did, it started on all 4 and did the last few km perfectly.

[Jaydee]

7 hours ago, Joseph said:

Had a bit of trouble getting it to start, but, when it did, it started on all 4 and did the last few km perfectly.

Maybe it is an electrical issue with the coils but running on two can be fuel related too.

Are your carbs twin fed? Hardly one the lines going soft with the heat and kinking, thus shutting down that bank of two carbs. 

I know you stated that you changed the lines but it could be that the line is being pinched/stretched or have some tight angle at the tap. When warmed up, something collapses(?) 

 

[Joseph]

The fuel system i have has a 10 mm brass spigot on a custom plate on the tank, feeding 2 8mm lines from a T connector. They go into two inline lever actioned universal petcocks, that then send to each pair of carbs.

Up to the taps i am using thickwall auto fuel line, from the taps to the carbs i am using suzuki style fuel line in springs.

I have looked and can't see bends. But if it was running on 2 cylinders because of fuel starvation surely it would be 1-2 or 3-4 ?

[Dezza]

Maybe try checking all the rest of the ignition wiring (ignition switch, kill switch etc.) then try another CDI to narrow the problem down

[denisd]

I'm thinking electrical rather than fuel, I'm also thinking lads in warmer, dryer climates don't have as many electrical issues as we do in the few damp islands west of Europe.