Before I spend £80+ on a stick coil...

(2004 1150gsa twin spark)

Just wanted to check with the assembled masses the following:

I was just about to get onto the ferry last week when the bike started to surge a bit riding through the car park. However give it some more juice and it cleared itself. The servo unit then failed the next morning (rear brake control circuit) shortly the followed by the front wheel speedometer sender... Yes it was quite a morning.

Whilst I appreciate that the speedo is nothing to do with the servo brakes, I've noticed that the bike seems a tad laboured on the trip through France and had difficulty sometimes idling when either warm or cold in that it would start, run steady at about 1k rpm before trailing off to about 600rpm over about 30 secs and then splutter and die. However it would always restart and so long as I gave it some beans in second to get it through the laboured patch it would run ok but felt a little laboured. I also started to notice the whiff of petrol when stationary sometimes.

To me this sounds like the stick coil (s) is/are beginning to break down and as such I did the 'Steptoe' test of pulling the secondary caps and whilst it still ran, the rev dropped slightly and it began to sound more rough especially when diosconnecting the right hand side. Whilst I have not had the plugs out yet to check for colour (new last year during the service), I checked the TPS voltage a couple of weeks before and it was about 0.369v and all was running fine, I've also lightly sprayed some brake cleaner around the TB'd to check for leaks and there isn't anything obvious. I also need to check the air filter but it was replaced last year and was fine a couple of months ago.

Soooooo my question is whether anyone else has experienced similar symptoms after their servo failed but before completing a servo-ectomy (which is happening this evening when i get home from work). Logically I can't think why it would but if it means I don't have to buy a another stick coil, that would be a bonus. Incidentally I replaced both of them about 3 years (15k miles) ago - how long are they supposed to last??

Any thoughts much appreciated.

Stick coils are as the name suggests a HT coil wrapped to fit on top of the spark plug. All HT coils can break down under load. The stick coils suffer from being exposed to the elements, water and heat. Clearly from your symptoms and test results they haven't failed completely, but the right one could be breaking Down. Unfortunatly a visual check would probably not be conclussive as to failure as even if they are swollen they could still be fully functional. But having dismantled one, if mine was swollen then I would replace it, as the earth lead connects to the metal outer casing which on the earlier type corrodes and swells.

From your symptoms, swop the coils left and right, re do your test, and see if the fault transfers. That will tell you.

Good luck

Ian

Thanks Ian.

As a slightly seperate point, does anyone know if there was a defiinite answer to doing away with the stikck coils in favour of HT leads and using a secondary coil from BMW or Ford etc? I've just spend my lunch break reading this ADVRider link which seems to suggest there are ways of doing it but wondered if anyone had tried it successfully on this side of the pond and if so, how is it best achieved?

I sold my 2003 1150GS earlier this year at 96,000 miles. At around the 4 years and 36,000 mile mark if my memory is correct I had stick coil issues. They were replaced with an upgraded version from BMW and had no further issues. Even if it is the problem I'd be inclined to stick D) with them as the later ones don't give as much trouble as the early incarnation.

You might also consider checking/changing your fuel filter. Unfortunately it's inside the tank. The little studs that secure the plate to the tank are easily sheered off so be gentle, use penetrating fluid such as Plus Gas. Much better than WD40 for this application. If it hasn't been changed that could be your problem.

Another less likely possibility is that the filler neck drain pipe that comes out by the rear brake master cylinder is blocked and water has been getting into the tank. There is a shallow drainage recess around the filler neck with a hole that the drain pipe connects to. It routes through the tank, exits through the plate referred to above and then down to atmosphere. Quite a well known issue. A search will reveal threads.

Green Boy said:

Thanks Ian.

As a slightly seperate point, does anyone know if there was a defiinite answer to doing away with the stikck coils in favour of HT leads and using a secondary coil from BMW or Ford etc? I've just spend my lunch break reading this ADVRider link which seems to suggest there are ways of doing it but wondered if anyone had tried it successfully on this side of the pond and if so, how is it best achieved?

Click to expand...

My main coils were replaced last year after a few months of diffuse symptoms including stalling running rough and finally sooting up an O2 sensor.

My fuel consumption returned to normal do I believe the secondaries are ok.

My plan is to use a pair of three wire stick coils from an auto parts supplier. Strap them to a mounting bracket then run an HT lead to each secondary spark plug.

Stick coils have power, trigger and earth leads with HT out at the nose end. I'd expect a set of four coils could be bolted under the tank and HT leads run to the plugs. As it's already suppressed there should be no need for resistance plug caps.

Snag is more risk of insulation leaks between coils and plugs. But worth a try.

Bendy toy said:

My main coils were replaced last year after a few months of diffuse symptoms including stalling running rough and finally sooting up an O2 sensor.

My fuel consumption returned to normal do I believe the secondaries are ok.

My plan is to use a pair of three wire stick coils from an auto parts supplier. Strap them to a mounting bracket then run an HT lead to each secondary spark plug.

Stick coils have power, trigger and earth leads with HT out at the nose end. I'd expect a set of four coils could be bolted under the tank and HT leads run to the plugs. As it's already suppressed there should be no need for resistance plug caps.

Snag is more risk of insulation leaks between coils and plugs. But worth a try.

Click to expand...

I'm a little confused

The upper plugs / stick coils are your Primary.
The lower plugs / HT leads are your Secondary.

Are you saying you are going to convert your bike to run with 4 stick coils similar to the 1200?

If you are going to use non standard components to modify your bike. It might be a good idea to ensure they will match the output from your Motronic. If you draw to much current you could damage it. (expensive).

Personally, if I can get 40k miles out of a set of stick coils, I'm not too concerned. Time will tell whether the new designed stick coils are more robust.

Well I fitted the new stick coils last night and...little has changed. I've booked the bike in with Steptoe on 6th October as a backstop but thought I'd check with the 'great and the good' to see if there is anything else that I can do ahead of this. To be fair I'm not likely to be able to check the fuel filter ahead of this date (Packer-thanks for the thought) but as it was replaced about 15k miles ago and I haven't been anywhere with kack fuel I don't think this is the likely the culprit. Incidentally I've had a remus and y-peice fitted for the past 2 years without a problem.

As of about 2 weeks ago, the basic symptons are:

1. A pig to start from cold. The fuel pump primes as normal and bike turns over but it won't start without the fast idle being on full and if I reduce this to normal then it tries to idle at abotu 500rpm before dying.
2. Once warmed up, it is rideable but sounds like a Harley in that it has a bark which I think is coming from the left pot if a blip the throttle. The idle is about 1k rpm but seems laboured.
3. If I start to open it up, anything over about 3k feels laboured like it's being held back by something and back fires off the throttle sometimes
4. It will get to about 70-80mph ok but if I open the throttle full after that, it will slowly excelerate but witha real 'harley-esque' roar eg. more sound that go if you get me.
5. When fully warmed up, it will restart if I stop it and will again idle at about 1k rpm

Some things I have checked:

1. Throttle cables are correctly seated and TB cables are free to rotate. Also the TB's snap shut when the throttle is closed.
2. Checked that there are no trapped/ crushed cables under the tank.
3. Pulled the spark plugs and these are a normal colour and about 12-15 months old
4. The primary coil wires seem to be in good condition and the earth cable is attached and in good condition
5. The TPS has not moved or been damaged and the BBS have not moved. These were checked and adjusted a couple of months ago
6. There are no obvious leaks around the throttle bodies as I sprayed a little brake cleaner around and nothing happened to the idle
7. I checked and adjusted the valve clearances and rocker end float as part of the service a couple of months ago.
8. I did a motronic reset just for the hell of it
9. The drain pipe from the filler neck is free to drain and I am not aware of any time that water could have entered the tank.
10. I put some injector cleaner in with the fuel that I got last night to flush things through.
11. The QR fuel pipe connectors appear to properly seal and there is no fuel leaks
12. The exhaust is not smokey nor is the bike using excessive oil

I don't have the equipment to start doing compression tests on the cylinders or fuel pressure but was planning to do the following:

1. Pull out the injectors, turn the engine over and confirm they roughly pumped out the same amount of fuel
2. Disconnect the primary coil cables from the coil and see if this makes any difference to the idle.
3. Pull the primary spark plug, ground them and ensure that there is at least a spark coming from them to prove that there is not a complete failure on them.
4. Remove the rocker covers and check that there is nothing obviously amiss with the valves.

If anyone's got any experience of this or any other ideas/ things to try, I'd happily except any thoughts or advice

Ok so I found the problem in the end. It turns out that when I removed the servo, I also removed the last relay in the box along the ABS relay as it wasn't labelled on my diagram or in the manuals. In case anyone else wonders what this is, it's a secondary load relief relay that just controls the primary coils so if you pull it, they don't fire....

This is where I found out what happened. Here are the wiring diagrams to confirm courtesy of the good peps on ADVrider

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