Rough Idle

[Brock]

A multimeter will check resistance of the coils, but it could be breaking down internally  You need some special stuff for that..

[Pezzz]

Kappy, easiest solution would be to swap out with known working one. If Yorkie has a couple to loan for testing then just do that. I think it will be a coil issue as well or something related to spark on those cylinders.

[Wombat]

Ok my turn 

Age old problem with electrics and coils is earthing out properly. You appear to be on track trying to isolate the problem one item at a time. I would have said also to change the spark plugs but as two are affected at the same time the coils appear to be the issue.

You're in good hands with advice from the guru 

My 2c

 

[kappy5003]

Thanks Wombat wish I had heard that earlier.

I've swapped coils and leads and plugs and the issue hasn't shifted.

So like you say an earthing issue.

I found something on another forum that implies a common wiring issue, which is the same side as I have.

http://www.st-owners.com/forums/showthread.php?77352-ST1100-ignition-problem-NOT-solved-Yet-!!

So next step in a few days is to play with wiring.

Cheers
Kappy

[kappy5003]

Just an update and fishing for some electrical expertise.

I've removed the coils from the bike and I have a el cheepo multimeter which I only know half how to use.

Iv'e checked resistance on the end of the plug leads and falls withing manual specs.

However when I check for resistance on other connections when I get readings it starts at say .4 and  watch the reading fall 000.1 or 000

When I check the 3P connector to primary coil there seems as one side has power or resistance left side and no reading for right side where the problem lies.

So we are getting to an area that's like a foreign country to me, so can I ask the Gurus with advise they use simple language.

Cheers
Kappy

[Brock]

I will have a look at the testing when i get a few minutes spare, and post what I can find out. Unless some one beats me to it.

[kappy5003]

I'm not sure how good my multi meter is and I'm not sure about.

The upshot is I believe the coils,leads and plugs are OK and probably the carbys.

[Yorkie]

There are 3 wires on 3p connector, black/white is common earth for both coils, the other 2 get power from ignition control module. I have a second hand unit if you need to try it. The common earth goes through bank angle relay.

[Panman50]

Hey Kappy, if someone can point you in the right direction to download a manual from this site section 18-5 and 18-7 will help.
I got mine from here but I am crap at working out how to load stuff.
I took 2 pictures but the files are too big.
Those two sections will show you how to troubleshoot and test the coils.
From what I have read it points to your ICM.
Hope this helps.

[Panman50]

Also there is a slight difference in the wiring between the standard and ABS models which is also in section 18.
Regards, Tom.

[kappy5003]

Thanks Panman,

 I have the Manual and I feel the coils are OK, I think its prior to all that, maybe the wiring leading up to that.

I'm waiting for the Guru/

[kappy5003]

Hi
Been doing some tests to figure out why the right bank is not firing.

I have swapped coils and the issue is still there , may reveal coils are fine.

Done some resistance test  on coils and as far as I can comprehend seems ok.

Now when I test the the leads to coils I  get a sorts of a reading for the left bank and none at all from the lead that feeds the right bank. (pic)

The same occurs when I test the Yellow/Blue and Blue /Yellow lead at the ICM.(Pic)

Need some guidance where to coil wire originates from as well as where the earth is grounded.

[Yorkie]

The black/white is the earth, I doubt that is the problem as a common earth will affect both coils. The coils get supplied from the ICM, this creates the spark when required.

[kappy5003]

I followed the colours to the ICM but don't know enough about what powers those wires.

Some of the readings I get don't make sense, but I feel there is a flaw that feeds the right bank.

I been spraying electrical cleanser on heaps of connections.

Somehow need to find if there is a breakdown in the wiring without having strip everything apart.

Fast running out of enthusiasm.

[Yorkie]

find the same 2 wires on ICM plug and check resistance between the and the coil ends, both should be almost zero, if they are it is a safe bet the ICM is the problem.

[kappy5003]

Latest up date.

Yorkie lent me an ICM to test, before I go into that.

I have swapped the coils around, swapped Plugs and leads and still right bank does not fire.

I did compression test the other day

Cyl 1 185 psi.
Cyl 3 170 psi.
Cyl 2 150 psi.
Cyl 4 150 psi.

So me thinks compression's are OK.

Back to Yorkie's ICM, plugged into Bike, checked all leads, ignition and left bank fires ......right bank nothing.

So I'm stumped, can the carby be so far out even though everything was put back the way I took everything apart, pretty sure about that???

So when I did shims is it possible maybe I cocked up and have the intake stroke as the exhaust stroke ??????

Will need to double check just to be be sure before I pull the carby off again???

I welcome suggestion Please..

Cheers
Kappy

[Wombat]

Kappy
going to jump in again. I have just read the posts again and offer this suggestion. It is hard to understand what you are experiencing and it may be prudent for a couple of us to visit you and observe and listen to the STead. A second set of eyes and ears may be helpful although Pit Crew says i cant find anything in front of my eyes and I dont hear her when its important. Fuel does not seem to be the problem so I wouldnt touch the carbies. Electrical issues may be an issue such as something shorting out when hot etc. My STead usually wont idle with standard plugs without choke so you may have a couple of issues clouding the main problem.
Regards Wombat

[Piet]

Hi Kappy,  First off top marks for your getting in and getting your hands dirty and not being daunted by the work. I really mean it.  Well done.   As tough as it is and as super frustrating as it gets sometimes, you are getting some really good experiance in all of this that you can in turn help someone else with.

If I read this right,  and if I am understanding things correctly,
She does not want to idle properly and is hard to start especially when cold.
No 3 does not want to fire. 
Does #3 fire at higher engine revs?
Checked coils & ignition, plugs etc ... All seem OK.
So going back to the carbs,

Each carby has 2 significant jets ( not counting the needle valve metering) There is the idle or pilot jet and the main jet.
Pilot or Idle Jet below


Main Jet


The idle jet is providing fuel at idle and should continue to provide a small amount of fuel as revs increase.  However as the revs do increase the main jet cuts in and provides a higher volumn of fuel needed. 
From the symptoms it sort of sounds to me that #3 idle jet is blocked.  This would meen at idle it wont fire because it has no fuel feed.  Get the revs up and the main jet will provide fuel so it should start to fire but it might be running a liitle lean at revs because its getting slightly less fuel than the other 3 carbys are supplying.  It would definatly run like a hairy he goat at idlle and perhaps a tad less than optimum at lower midrange revs and near perfect at high revs.
If this fits the symptoms then I would go back to carby 3 and pull the iddle jet and make sure its clean and can pass fuel.
I had my sons VTR250 fuel go off and foul his carby's.  The residual gum blocked his pilot jets.  It was tough to clean as well because the holes were small and the gum was very tough.  I boiled the jets. And (not advocating this) I used a single  steel wire from my wire brush to clean it out.  Nothing else would unclog the jets.  Sharp steel on fairly soft brass pilot jets is not very good, and I may have reamed the jets in the process but ...  it works fine now.

 

[kappy5003]

Thanks guys

Wombat that sounds like an excellent idea, I would welcome the extra eyes and the company, difficult to get way from here at time.

Piet, No 1 and No 3 aren't firing at all, I've just about covered every electrical possibility.

Just this afternoon,I removed the plugs of 1 & 3 and thoroughly cleaned them with carby cleaner and dry them thoroughly.

After re installing fired up and ran for 10 minutes, stopped removed No3 and guess what dry as a bone, repeated running for 10 minutes removed No 1 also dry.

So convinced no fuel.

Spoke with Chris from Honda shop, he confirmed that sitting for nearly 2 years presents problem and O ring etc should be replaced after clean plus may need a further clean may have pushed varnish into a Small hole.

Pretty sure timing is right, actually runs quite smoothly on 2 cylinders, considering.

[winston66]

If the problem is blocked idle jets due to a build up of gum and other residue, I would try adding  on a regular and ongoing basis some good fuel additive to the petrol.
I have found that a product called F10 is an excellent fuel conditioner and I have been using it for many years in any vehicle that I have had, Even in my vegetable oil fueled diesels.
I am currently using it as a injector , Carb cleaner , Fuel stabiliser -conditioner in my Statesman, MX5, and the three motorcycles.and a stationery 10 HP diesel generator set
Since starting to use the F10 I can honestly say that I have never had any fuel type problems in any of the associated motors.
Naturally if the problem is a blocked idle jet any fuel additive possibly might not work until it has had a chance to get through the offending jet and clean it out.
Cheers Winson66

[Piet]

OK, so 1 & 3 are not getting fuel.

I know this is really an obvious question.  After the cleaning of the carbs and putting them back ... then later you had them out again.  On the 2nd (or more) time out, did the bowls on the #1 and #3 carbs have fuel in them?  Could it be that the fuel is not filling those 2 carby's?

I know the answer must be yes they had fuel.

I am not sure we can do this easily, as I am thinking about engines in general not ST11 specific.  Are you able to start the engine with the air box off?  Or at least with the option to put your hand over the air inlet side of the either #1 or # 3 carby?  If yes. What I would do is with the engine running at lets say 2000 or so revs.  I would block the inlet to a carb completely.  This should create a large vacuum and pull lots of fuel through the carb and into the cyclinder.
If your hand gets wet with fuel or you know fuel is arriving then you might be able to regulate the mixture very crudely by progressively applying your hand as a choke.  Either richer mixture by closing or leaner by removing, allowing more air.  If we have spark, timing is good, and some fuel going down its throat we should be able to get a suitable mixture to get that cylinder to fire and run, rough but working.  I would do the same with the other as well.

Is this possible?

[STroppy]

An easy way to tell if it is carbies or electrical is remove air cleaner and pour a little (emphasise little) petrol into one of the right carbies . . Try starting does it fire . . Same with the other carbi . . Does that cylinder fire . . Finally try a squirt into both right carbis and see what happens . . If they are firing . . Albeit for only a short time . . You probably do not have an electrical problem . . . Carbies likely at fault.

Having said all that it is strange that both carbies would be experiencing the same problem at the same time whereas the lefties are not . . But you have swapped the coils and leads around and the problem remains with the right side . . Maybe a faulty ICM but you have replaced that and still a problem . . All wiring disconnected, cleaned, tested and reconnected?

All spark plugs replaced with new ones?

[Abe]

As STroppy said, good idea, or try some carbie cleaner or "start you bastard" instead of fuel if that helps.

Yeap it's spark and/or fuel. Now which or both 

Did you change the float levels at all ??? Should be 7mm from memory.

[Abe]

OK, found the website I have used before, you may have already seen this one, if, so disregard.

http://koczarski.com/ST1100/CarbRebuild/Carbs.htm

[kappy5003]

Ive cleaned the carby but maybe not as well I had expected.

Anyway thanks Stroppy and Abe, I never thought of that, thats why 2 or 3 heads are better than 1,so just been out to the shed and sprayed a little "Start Ya Bastard" in the air intake of 1 & 3 and yes fired.

So one would think Carbs.

So think I'll get a kit and do all the O rings etc, I've come this and its pieces may as well do it properly as already done.

Fork seals and fluid,
New tyres, and dyna beads,
New front rotors and pads,
Coolant change
Bled clutch and brake systems,
Shims replacement (bit picky but I'm a bit like that)
New spark plugs,
Replaced front wheel (old one had bend in it, don't ask long boring old story)
New battery.
New Top box

That's about it ATM.
How things are ATM