www.boxertrix.com

Intermittent problems with 1100S, featuring occasional lack of power; part-load hesitation; lousy running in rain; increased fuel consumption -but little consistency. While this had little effect on the road I read lots of your stories here to compare notes on how symptoms have shown up for others.

FUELLING
The feel was to me both cylinders suffering, so I assumed it was more fuel starvation than electrical.
Ruled out fuel pump failure (by ear) i. supplying OK pressure I initially suspected either a clogged fuel filter (replaced but no joy) or failing fuel pressure regulator (tending to stick closed) but as that's a bitch to reach I hoped it wasn't the root cause.

IGNITION
Changing tack I read more about the ignition triggers (Hall Effect Sensor) and investigated.
Checked the winding resistances and condition of the (Single spark) ignition coil -all OK.
Built an HES testbox (as Dana Hager's excellent instructions http://bit.ly/1gLXqsd ) but having got consistent Yes signals from both of these when cold and @ 110 C, I visually inspected the wiring; found and repaired a nicked wire leading from the HES to the Motronic, and guessed all would be well.

WRONG!
Bursts of poor running over a riotous long weekend in Scottish Highlands convinced me I had not found the problem.
Next I got hold of a good s/h coil and swapped it -no change:
-and worse while I was out testing that by a 6th gear roll-on from 1500 revs, it broke down with intermittent spark and fuel flow giving 2 huge explosions in the exhaust but non-runner. Those back-fires were loud enough in rural Suffolk to be a 8-bore and I didn't want to rupture the exhaust so discouraged my attempts to restart...called recovery and bike now sulks in the naughty corner in the garage.

COVER ME, I'M GOING IN
to recondition the whole HES assembly [extortionate £220 @ BMW or £110 from Greek maker] have :
# bought high temp wire ( http://ebay.eu/1a4NOzb )
# bought heatshrink tubing
# ordered new sensors -see CYHME 56- from Chinese mfr http://bit.ly/1aJqRCy.

When that's done, to properly test the ignition static timing I would like to fit one of the (later 2-row pattern, 6-way) signal connectors to my test box, but neither RS nor Farnell have stock of what I want; [AMP Micro-Quadlock 1-967587-3 and 1-967616-1].

TWO Qs
Q1 - can anyone suggest another connectors supplier?
Q2 - beyond getting bike running, how can I prove that I am not barking up the wrong tree?

Ummmm ..... sidestand cut out switch failing in the wet? Try disconnecting it and looping the connector

Like the way you're thinking...good tip -however have checked that, along with Neutral switch (whilst replacing gearbox) and Clutch switch...none was a problem.

Gum tree?

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I suspect I'm well and truly...

From what you describe my money would be on the HES unit. I also built one of the little HES testers, so it will be interesting to see if it does its job, as from what you say it indicates your HES is good?

Dan Cata is doing lifetime guarenteed units cheap-ish or fixing your original one. Maybe he will be able to tell you where to source the connectors?

Linky: http://boxer-upgrades.webs.com/apps/webstore/

I have a spare secondhand HES for my 1150gs which should be the same as the R1100s. If you want to borrow it let me know.

Good luck!

R-man wrote:-and worse while I was out testing that by a 6th gear roll-on from 1500 revs, it broke down with intermittent spark and fuel flow

Curious how you diagnosed that. Was the pump intermittent? Was that a full throttle roll on from 1500 rpm ?

-Fatnfast- yes I know Cata Dan's service is good, its just that I'm being tight about the cash. Also a brand new unit the Greek (see http://bit.ly/17XXwmo ) price is £89 + 15 P&p.

I will have one more look for the connectors then drop Cata a line...
The tester design was from 1994, with the earlier connector that you could get a mini-croc clip into, and its much harder with the newer design which has deeply set, fragile pins of 0.6mm square section -which is why I want the spare loom side connector.
Yes please to loan of your spare (later S plate & connector is same as any 1150) for a few days -I will PM you.

-nab301- not so much diagnosis, as the long toll of ruling things out one by one...fuel pump primes on key turn, and reaches pressure within 2 seconds (as always) then I never hear it again; since pump does not run again its fair to assume nil leakdown from regulator back to the tank.

Yep, as bike seemed to be running beautifully so I was being cruel on purpose; big handful of throttle at 1500 revs; immediate hiccup, pop and surge, then died and rolled dead as a doornail into side turning...so at least it was decisive!
I will get things apart again tomorrow and check for any new problems...here we go again

Will post the HES on Monday for you to try (pm'd you). What I did with my tester was instead of crock clips I twisted the wires together and ran some solder over them to make my own little pins. Works a treat.

Glad I haven't a clue what you are on about.
Slightly pissed however after watching our performance against Australia
Hint - I am from Northern England

R-man wrote:--nab301- not so much diagnosis, as the long toll of ruling things out one by one...fuel pump primes on key turn, and reaches pressure within 2 seconds (as always) then I never hear it again; since pump does not run again its fair to assume nil leakdown from regulator back to the tank.

Yep, as bike seemed to be running beautifully so I was being cruel on purpose; big handful of throttle at 1500 revs; immediate hiccup, pop and surge, then died and rolled dead as a doornail into side turning...so at least it was decisive!
I will get things apart again tomorrow and check for any new problems...here we go again

Afaik pump priming is just timed and not related to actual fuel pressure(which is mechanically controlled by the regulator) I had an in tank pipe come off (so no pressure) and the pump prime on time didn't vary. What I did notice was I couldn't hear the pump "loading up" as the pressure increased just before it switched off.
Some of the symptoms in your first paragraph sound similar to a failing lambda sensor , ( apart from the wet weather) Full throttle at any revs would (according to my understanding of what I've read here by R550s) go open loop, presumably rich, which combined with low revs might cause what happened to you ? Maybe weak spark ? are the plug leads ok?
I may try a few full throttle, low rpm runs myself just to see!

FatnFast - thanks for your kind offer, which may keep me mobile and sane!

Nab301 - never thought that initial pump run could be timed, which explains why it always runs the same burst each time...another piece in the jigsaw.

Thanks all. Ive stripped the wiring on my duff plate, and inside its horrible -amazing that a signal ever got through at all. Will post pictures this week.

You will probably gain on mpg after this repair!