random intermittent well running machine

[Zampano]

this might one of those questions which have no definitive answers. ..not is God real? ..because really, what sort of God would allow famine, war, and dealer prices to exist.

For the most part my bike runs relatively well. Timing chain slapping around drives me bonkers (I will be asking for advice fairly soon when I try to remedy that), noise from the clutch, and occasional backfires aside.

What I notice is that on some days it runs "very well." As if something is faulty or semi-faulty most of the time and then for whatever reasons decides to do its job. It's not related to cold/warmed-up. It's one of those things where I'll start the bike and I can tell right away from the sound of the engine that this is going to be a good ride. The power delivery is more smooth and predictable. The bike feels like it is getting just the right combo of fuel/timing. And, oddly, the timing chain guide noise is diminished.

I've covered a portion of the list of 8 million things to cover; but as noted in the bridge on the river kwai, "there is always the unexpected"

From day one I've felt the bike is "off" a bit; either a timing or air/fuel issue. Could certain sensors be working intermittently and easy to troubleshoot? I've cleaned/checked &dielectric greased every electrical connection I've run into (and ECU plug). Within the last few months I've addressed, injectors, fuel/air filter, vacuum leakers (there could always be another). Plugs were changed while at the dealer last year when valves checked.

- The timing chain guide noise apparently won't affect things. I'm not totally convinced of that.
- I need to read more about the Hall Effect sensor, so I'm not sure if that could be the source, but seems possible.
- There is the CO adjustment; which I'm not sure has ever been done. That would be lumped into the AFM air/fuel category.
- Also temp sensors which I assuming lead to air/fuel variations via the ECU ?

My thoughts are that certain things are all or none (e.g., vacuum leaks, exhaust leak, bad plug, bad injector.) My money is on an electrical/mechanical sensor which is sometimes working properly but usually half-assing it.

In any event, I thought I'd post in case someone had a similar schizotypal engine and accidentally found a big fix after changing out a bad/faulty item.

thanks.

Cheers

[Motorhobo]

You know, Zampano -- I have a similar issue. It seems when I ride with a half-shell my bike runs kind of rough -- as if there were all kinds of gremlins running around in there.

But then when I ride with a full face, it's silky smooth and it's almost as if all the gremlins just went away!

And then if I ride with earplugs, it's like it's a brand new moto! 

I don't get it...is that just a coincidence or what? :riding:

[Zampano]

reminds me of when I fixed a dozen rattles in my old saab with a new set of speakers.

the problem with the K is that it teases. It shows you how it could run, all the time, but then taketh away after a short while. So now each time it is running with what feels like a slight timing issue or a subtle lack of proper fuel/air/power; you know without doubt that there is something preventing it from performing as you know it can. This can be applied to wimmen as well  :dunno2:

Either way I am happy to simply arrive at point B and return to A.

[drut]

Strangely basic mundane faults such as breaking down HT leads can produce intermittent and apparently unrelated issues.Diagnosis is only possible when fault occurs but a check of basics i.e.compression check,sensor values and vacuum gauge readings would be my starting point.

[Zampano]

thanks. I'm thinking along the same lines. I've covered a lot of the bike but there's always a few more items. I was hoping to find some symptoms where I could rule things out. Probably a dozen or so major culprits.

Eventually I'll compile a big list of items and rule-in / rule-out / could-go-either-way scenarios. So if your bike isn't, say, backfiring constantly or blowing out techni-colored smoke you can cross things off the list.

I've done a lot to this machine and it runs decent but there were days before I fixed a long list of bad items where it ran exactly the same. It's odd. I must have a dud. But a year ago I had it at the dealer and the old K-guru felt it wasn't too bad. Just a little underpowered. Either way I won't get around to fixing everything until I have a new KTM adventure to ride while I tear the K down.

[Bfbob]

I'd call this a long shot, but easy to check.  I had a similar issue on my '96 K1100LT.  The problem turned out to be the exciter wire on the alternator.  It wasn't pushed fully onto the spade lug on the alternator, just resting on top of it with only its own weight holding it in place.  The intermittent connection caused by the engine's vibration caused it to bounce around, throwing off tons of RFI and confusing the computer.  The diagnosis came when it fell off completely, causing complete charging failure.  When it was found and reattached, it cured both the charging and the running issue.