ignition help required urgently

[Padster]

The three way connector under the tank (on the left side of the bike) is well known for corroding. On mine it caused the symptoms you describe. I had to re do the connection as it had corroded all the way through. It is the red ignition wire that is usually the problem.

[andyp9181]

i would check what padster said, this happened to me a week or so back, luckily i was about 2 min from home! the wires were really badly corroded away, also the bike wasn't running as sweet as i wanted but after the fix it's been great!

i have since been to the car scrap yard and got a rubber sealed twin connector of a car, it has two parts that connect with a rubber seal to keep the rain out.

[pilgrim]

It will be a simple thing to rectiffy, just a loose connector, dirty contact or break in the wiring somewhere. That could be water inside a connector too. (otherwise it runs ok?) If it's only just happened then that's the reason.......water. 99.9%

My best guess.

[metalforever]

cheers lads, i need to locate this connector now!

Which connector are we on about? after having a look over the bike all i can see is the TPS (Throttle Position Sensor) on the left under the tank...

When we say 3 way are we suggesting 1 set of wires going in and 2 going out to different places or simply a 3 wire connector block? Help

[CD]

Its been out in heavy rain so best to check-out every electrical connector that you can get at and fix any that look dodgy. It seems an OTT idea, but sooner or later they will all be causing trouble so well worth the effort.

As you have sparks and the engine runs (albeit, badly) its unlikely to be the coils causing trouble.

It could also be water in the fuel (via the filler cap seal). So while the tank is off, its worth dropping the carb float bowls and cleaning them out.

[metalforever]

Pardon my ignorance but how do i actually clean a connector? just with a connector cleaner aerosol or similar? should i maybe put a dab of copper grease or similar in the connectors when i replace them?

any advice is much appreciated as im meant to have an MOT friday...

[CD]

Contact cleaner, jeweller's screwdrivers to scrape off the crud and some small pointy pliers to squeeze the female connectors on any that seem a bit loose. Its not techy just be careful. Some contact grease (e.g. from Tandy) is also a good idea to keep corrosion at bay.

If any are too far gone fit new connectors. Crimped is better than soldered. Heat shrink sleeve can also help.

[metalforever]

Well i've had all the connectors appart except the ones directly underneath the airbox/ignition area and everything looks spot on, the tiniest bit of of corrosion on a couple of connectors but nothing major.

I do think however that the ignitor box may have gotten fairly damp lately as i removed it and it seemed to me as if there was quite a bit of water on the connector, hwoever this may have been wd40 from last week (although it didnt smell or taste of it! )

I'm going to try running the bike tomorrow again and see if ive solved the problem, if not im going to try a new pair of coils with leads and caps.

[chunk166]

I would check the one's directly under the air filter, as they do get a lot of road crud on them,there is a block with 9 connectors in which is part of the ignition (right hand switches) also as said the main ignition connector as i have had to replace all the connection for ignition & lh switches after my bike (D9) left me stranded 10 miles from home & the breakdown co didn't want to touch it? so be on the safe side it only takes 10 mins to check them.

Ray

[CD]

The engine does run so its unlikely to be both coils. The electronics and ALL* wiring connectors are the first areas to look at. Water in the carbs is also possible. An eggcup full can cause all sorts of hassle.

*OK - perhaps not the lighting circuits.

[metalforever]

I forgot to mention, the bikes very reluctant to start from stone cold... if that helps anything at all.

On another note, ive cleaned and wd40'd all the connectors just to ensure theres no water anywhere but the bikes still running crap. I've ordered a single coil with leads (no caps unfortunately) from ebay and im going to try that in place of the right hand side coil first and if that doesnt change the running ill try it on the left. If that doesnt help i'll have to assume that new coil doesnt work or its not the coils on the bike.

[metalforever]

Problem solved - spare coil works.

[CD]

Well done :-)

[metalforever]

And she's gone... again.

shes running nicely at idle and in neutral but when under load she tries to die at about 3000 revs. Whats funny though is it feels almost like fuel starvation... until it goes beyond 3000 revs and it smooths out a little until later. Whilst under load if you throttle on quickly she dies again.

I have a nasty feeling its either fuel now or possibly the ignitor box because that controls how many times a plug sparks at any given point. which makes sense in my head, also, it did get damp/wet.
I think what i need is some of fresh fuel to completely elliminate that

[bobh]

Agreed, water (or other contamination) in the fuel could cause these symptoms.

Drain off the float chambers, and better still take the covers off to make sure there isn't any evidence of crud that might be partially clogging up the jets. Check the fuel filter too for any signs of bits.

You really need to take the tank off to thoroughly drain it, either through the filler cap and/or by removing the tap. Rinsing with alcohol (meths or ethanol), which mixes with water, will make sure any traces of water are removed, but maybe that's going a bit far.

Good luck - Bob

[CD]

You'll need to take off the fuel tap to totally drain the tank, because the filler has a lip around the edge.

The carbs float bowls are easy to remove as they sit on the rear side.

Its also worth taking off the ignition electronics box and thoroughly drying it - airing cupboard for a few days.

You can sometimes work out which cylinders are missfiring by the temperature of the down pipes. Alternate pipes cool (e.g. 1 and 3) suggests a coil or ignition fault. A pair running cool (e.g. 1 and 2) suggests fuel. One pipe running cool could be anything from plugs to coil to fuel.

With the frustration of it all, dont forget the "silly" things like spark plugs.

[metalforever]

Thanks lads, i did drain the float bowls yesterday and it seemed to help, if it is just rubbish fuel ill kick myself. can i ask, how do you open the fuel filter? i tried the other day and i couldnt seem to so that i could check its element.

the Ignitor units coming out today, getting a good hair drying and then leaving in the airing cupboard till the next time im off work. I'm then going to try a jerry can worth of tesco unleaded (the stuff i normally use).

Spark plugs have been checked and changed a few times now however the bikes going under a partial service in the next few weeks before i go to uni so that'll see it with brand new ones.

[CD]

If the ignition box is wet a hairdryer will be too fierce. Best put it somewhere warm for a few days to dry out. Also check the fuel pump is reliably getting power. All wiring and electrics (ign and fuel) must be fully checked out before you start taking any major stuff apart.

You must also fully drain the fuel tank and add a bottle of surgical spirit before adding any more fuel. The fuel filter can be replaced with a length of tube or you could get a small filter from a car spares shop. But poor fuel flow usually only shows up at full power so the filter is not at the top of the list.

[metalforever]

thanks CD ive gone and put the ignitor in the airing cupboard and it'll likely stay there till monday or so. I'll check the fuel pump etc too.

just to add i very much appreciate all this help as it needs to be fixed soon, before i go off to iceland ideally!

[CD]

No worries. :-)

Reading the last post I'm perhaps being over fussy about draining the fuel. But to be 100% sure its best drained. Another option is to disconnect the tubes at the filter and connect some hose so you can drain it into a fuel can. You can check the first 1/2 litre for water by draining into a large glass jar. You need to be on "Prime" to drain fuel with the engine stopped.

On the spark plus issue - the plug tips on my 900 all looked fine. However the plug bodies had gone rusty so I replaced anyway. Wow what a difference! The plugs must have been breaking down with age.

[metalforever]

Right i've darined the tank and i drained the first 3-4 litres into a clean container and allowed it to settle. at the bottom where some 'globules' of another liquid of which was seperated from the petrol. im guessing this is water, however there was no significant amount, i dare say <1% of the container was water.

Anyway i drained about 13litres of fuel from the tank into jerry cans and im letting the tank air dry with the filler cap open. Tomorrow i'll check the fuel filter if i can figure out how to see inside it. I checked my air filter and box again just incase that was the problem, but the air filters white/clean and dry so i dont think thats it at all.

furthurmore im going to have th carbs off and inspect the main jets. im guessing 5000 revs is about the point where the main jet comes into play and obviously because this is the point i cant accelerate past i think it had best be checked just incase.

Hopefully by eliminating the carbs and fuel i can rule out a fuelling problem. then if thats the case its back to playing with the electrics. I've changed 1 coil over however i have a feeling ive replaced a good coil with a good coil rather than a bad coil with a good. so if my problems dont clear up ill try one of the old coils again and THEN if thats not the problem im onto looking at the signal pick up thingy.

The only thing after that is then the ignitor i suppose!

[bobh]

Rather than letting the tank air dry, which might not get rid of any residual water drops unless it's left out in strong sunlight (what chance of that in the next 24 hours?) or heated with some sort of hot air device (possibly dodgy), you could try sloshing it out with some of the petrol that you've drained off and allowed to settle. As mentioned earlier, Pure alcohol is the ideal rinse because it is fully miscible with both petrol and water.

It certainly sounds as though the globules you describe could be the cause of the problem - the jets are so small that a non-homogeneous liquid (i.e. petrol with blobs in) won't pass through at the right flowrate, if at all, due to the surface tension at the boundary between the dissimilar liquids. And even <1% is an awful lot of water.

It may not be necessary to clean out the jets, but I guess while you have the tank off it's a sensible precaution.

Good luck - Bob

P.s. A thought - I wonder if some of this E90 or E95 petrol with a dash of bio-ethanol could handle water contamination more easily than straight petrol? Not that it's a good idea to use it regularly in an old engine like the Divvy's.

[metalforever]

Thanks Bob that was certainly insightful i didnt expect a small amount of water to cause problems. I must confess i still feel its going to be an electrical problem by just the manour of the problem itself, however once ive got fresh fuel i can atleast eliminate that from the equation and start buying all kindsa lovely electrical boxes, coils and plugs!

[CD]

Having found water in the fuel, I'd clean the carbs before spending any money. The jets come out easily and a bicycle pump is enough to blow them out and the carb galleries. Do each carb one at a time so you dont get any bits mixed up.

[metalforever]

Hey CD i was going to do the carbs but didnt feel i had enough time this morning even though it turns out i did. I reassembled the bike after removing the bits im selling and popped some fresh fuel in it. it ran almost straight away and quite nicely however it still didnt sound quite right. So i took her round the block countless times just to test and she seemed to improve with a bit of time running, and would only hold back when i tried to throttle on normally rather than smooth and slowly.

So back home i bypassed the fuel filter with a piece of tubing, this also seemed to help however when i managed to open it it was dirty and did need changing so thats on order.

So i've rulled out fuel, air filter/box, ignition coils (Im certain these arnt at fault now), plugs and caps.

That leaves me with the TPS unit, the ignitor unit and the carbs in my opinion, so carbs are coming out wednesday or thursday depending on my plans for the rest of this week.

I feel as if progress is finally being made though as i can atleast ride the bike now should i absolutly require it.

[CD]

To clean the carbs you wont need to take them off the bike.

The bigger jets are probably ok.
1) they are bigger so less likely to clog :-) and
2) When it was acting up, you quite possibly didnt open the throttle enough for the big jets to kick in.

While you are working in that area dont forget to check the chokes are all behaving properly.

The TPS changes the ignition advance according to throttle position. Instructions are on this www site.

[metalforever]

Well well well! the bikes a runner! and this time she feels like she means it, i think a fresh tank of fuel will do her some good and a partial service wont go without a miss.

I have noticed though that one of the tappets seems to have gotten louder, this could explain why ive had poor running although it could be in my head, regardless its all good now, just needs a good airing out i think!

[CD]

A loud(er) tappet is unlikely to make much difference and that's (almost) always better than a quiet tappet.

If the plugs have done more than 10K, they'll be worth replacing.

[metalforever]

Neah theyre freshish plugs but theyre getting swapped anyway, im also going to run a tank of redex through the bike just to clear any residual crap thats left in the carbs.

on another note this is what i found when i cracked open carb number 4:



Quite alot of rubbish in there, including lumps of a varnishy-gooey material. And the tide marks were a pain to remove without carb cleaner, but its all good now because shes a runner!

[CD]

Cillit Bang does a good job, but dont leave it on the alloy too long.