Follow up to the "Centre pot gone AWOL" thread

[Loops]

Hi Guys,

Ref; 1999 885 efi - galactic mileage (72-73k) fully serviced though.

Following on from my previous thread after the center pot mysteriously came back to life after charging the battery I've managed to do maybe a 100 miles or so.  Not much I know but weather has been cr*p over here.

Yesterday was fabulous weather wise, too good a chance to miss and the GF was having her hair done so a couple of hours available to go play on Tiger.

But Tiger has other ideas.

She'll spin over and almost fire up.  Like one cylinder firing after a 5-10 sec prod of the starter.

Eventually the battery dies.  Even jump-starting off my diesel Subaru (big battery) has no luck, just every now and then a cylinder fires but she doesn't start.

My thoughts are either intermittant spark or timing is out (which shouldn't be possible) so maybe intermittant trigger (dodgy crank sensor)

So I've stripped her down.  Checked the plugs after previous suggestions and they look fine, maybe a touch sooty (light tan) but much better than my old XS1100 ran with.

Next thing I checked the coil packs.  Between the two input pins I get 0.7 ohms, which according to Haynes manual is good.  However when I check the output side I get open circuit.  Physically I removed the rubber boot clamped on test meter lead to the spring and with other lead on 1) the body, 2) the -ve input and 3) the positive input each reading is open circuit.

To me this doesn't seem correct as the coil packs are really only transformers so should have a resistance across both windings.  Does anyone know if this is normal or have a spare coil pack to double check my test?

Next test was the crank sensor - Haynes says the resistance should be 1300 ohms (1.3k ohm) - mine is reading 500 ohms or about 1/3 of specification.

Again anyone else got any experience of checking the Crank Sensor this way?

Currently I think my coil packs have all died - but all at the same time???  Seems very odd.

Cheers

Loops

[Loops]

Well that must be a first.

No-one knows the secondary resistance for the coil packs??

Anyway turns out mine were fine.

How do I know?  Well I called my Triumph Guru 'Clive' and he said if I'd been trying to sart it a bunch of times it was likely that the plugs were sooted up.  To me they looked OK.

But we swapped them out and put her back together and BINGO fire up straight off the button.

I did the ECU reset, start no throttle and let run for 14 minutes after the fan first started.

Those plugs weren't even 6000 miles old either.

All ready for a test ride..................but the heavans opened and it's pouring down.  Maybe clear up this afternoon.  Maybe.

OK off for lunch - will keep you up dated.

Cheers

Loops

[Mustang]

yep doesn't take much to flood the engine with petrol when they crank over slow and once a plug get's 'wet' it is usually buggered for good

what is actually happening is the excess fuel is causing the plug to ground and not producing a spark it needs to have a gap to jump and the excess fuel is making a good solid path inside the plug to ground the center post leaving no gap to jump for the spark

[Loops]

So it seems Mustang, I think I must have let the battery get bit too flat and tried to start her. Result a slow turning motor but no spark.

Chalk it up to one of lifes lessons I guess.

I now have one of those solar panel trickle chargers (£10 at Maplin) on it all the time.  Even on a cloudy winters day it puts out 18v, more on a sunny one.

Free electricity it's they way forward.

Anyway managed to pop out his afternoon for a 125 mile jaunt, the wind made cornering 'interesting' and crossing the bridge onto Hayling Island an Olympic strong man sport trying to stay in the lane.

Pleased to report Tiger now behaving properly.

Cheers

Loops

[tazshido]

I have had a few bikes that loved to eat spark plugs. On my 1983 XV920M (midnight Virago) I had to carry an extra set of plugs at all times. I would come out on a warm humid day to start the bike and after firing up would seem sluggish. I could get the plugs swapped out in about one and a half minutes. It happened THAT often that I got real fast at it. She would run like a champ with clean plugs. After getting to my destination or a good stopping point on the trip I would clean the fouled plugs with a wire brush and denatured alcohol and they were ready for the next time it happened. I couldn't figure out why the bike did it, Yamaha couldn't figure it out and two other non-stealership shops were shrugging shoulders too. It's just one of the quirks that particular Virago had, they didn't all suffer from it.
Just like my woman, I like a bike that demands some attention.