Intermittent ignition problem

[crimsontracer]

I have an odd problem that is so intermittent I cant DX it. Mainly because it happens sometimes when I am on the road and then doesnt do it in my shop.

Basically it feels like the bike is running on two cylinders. Runs clean, but no power if that makes sense. At first I suspected a fuel issue because it ran like it does if you run your tank down, right before you switch to reserve. The first time it happened i flipped to reserve and the it went away. Pulled to a station and I had tons of gas left. flipped back and it ran fine. then it would do it again and id just fiddle with the petcock knob and it would clear up.

So I replaced the cock.

Everything seemed to be fixed for about a week. but then it did it again. This time I notice that I cant get it to run right. So I shut it down and let it sit for about 30 seconds, fire it up and she runs great.

Let me start with what has been done

-Carbs have been COMPLETELY cleaned the RIGHT way. I promise.
-Ignition coils have been replaced along with plugs, wires, and boots.
-New fuel petcock with tank filter. NO INLINE FILTERS

Does this sound like a bad coil possibly? A pickup issue? Am I missing something?

Thanks all!

[92xjunker]

Crap in the carb bowls....kinked fuel lines, especially when they get hot.

[crimsontracer]

Thanks for the reply. Both of those make good sense.
However, I have had the carbs apart like 5 times in the last two months and there is zero crap in them. Fuel lines have clean routing.

[92xjunker]

Coils....maybe ...

[crimsontracer]

Oh! another piece of info i forgot to include. At sustained low speeds (25-35) there is a ticking sound that comes from the motor - but only under load. Not tapping like valves. almost sounds like someone tapping to pieces of metal together. slow and rythmic. Like 3 ticks a second. thought maybe that was a trans issue but thought it might also me another symptom of a coil.

wish i could get it to do it in the garage but only happens under load.

[foxox]

Unfortunately I don't have any really good immediate ideas for you but I feel your pain. I might be going through something similar with my own bike (http://katriders.com/vb/showthread.php?t=136980&page=2). The alternator can make a clanking sound: http://katriders.com/vb/showpost.php...78&postcount=7 and it made a loud clanking for me when it completely fell apart. If I figure out what's going on with my own bike and it still seems apropos here I will let you know.

[crimsontracer]

Unfortunately I don't have any really good immediate ideas for you but I feel your pain. I might be going through something similar with my own bike (http://katriders.com/vb/showthread.php?t=136980&page=2). The alternator can make a clanking sound: http://katriders.com/vb/showpost.php...78&postcount=7 and it made a loud clanking for me when it completely fell apart. If I figure out what's going on with my own bike and it still seems apropos here I will let you know.

Just read your post - yeah i understand. Phantom symptoms that are hard to find - especially the cold cylinder thats never consistent.

I did notice that sometimes i hear a definitive CLANK. floppy kickstand. Maybe for you too?

[crimsontracer]

I believe I got confirmation on it being an ignition issue rather than fuel. Left work yesterday and could tell it was running on two. Gutless and sounds like a 350. So I brought it up to speed, about 70, and while letting the wheels turn the motor flipped the ignition off and then on. Coughed a second while it cleared wet plugs and then was running great on all 4 for the duration of the ride.

Is there a relay in there before the coils?

[foxox]

The standard arrangement is that the coils are powered by the same lines that go up and through a bunch of other stuff (ignition switch, engine start/stop switch, etc.) before getting to the coils. These service manuals have the wiring diagrams in them http://katriders.com/wiki/index.php?...Service_Manual

There is the "coil relay mod" which you can do to add a relay so the coils get full battery voltage: http://katriders.com/vb/showthread.php?t=116991 If you do it with the standard quick disconnect connectors you can have it so you can un-do the mod in a couple of minutes by just removing the seat and tank and unplugging the wires and plugging them in how they are stock in case the relay ever fails.

[crimsontracer]

Thats an awesome mod and I think i will do it. should only take an hour or so.

However, based on the symptoms of it being an issue that can be corrected by ignition on off, and having viewed the wiring schema now.. I'm thinking that the problem is the relays in the igniter. If I'm reading it correctly - those feed the black and white wires on the coils - which are unaffected by the relay mod.

Anyone want to double check my thinking?

[skjeflo]

Oh! another piece of info i forgot to include. At sustained low speeds (25-35) there is a ticking sound that comes from the motor - but only under load. Not tapping like valves. almost sounds like someone tapping to pieces of metal together. slow and rythmic. Like 3 ticks a second. thought maybe that was a trans issue but thought it might also me another symptom of a coil.

wish i could get it to do it in the garage but only happens under load.

Does this ticking change its rate with road speed or engine speed?

[92xjunker]

Thats an awesome mod and I think i will do it. should only take an hour or so.

However, based on the symptoms of it being an issue that can be corrected by ignition on off, and having viewed the wiring schema now.. I'm thinking that the problem is the relays in the igniter. If I'm reading it correctly - those feed the black and white wires on the coils - which are unaffected by the relay mod.

Anyone want to double check my thinking?

+1 the key on/off thing says electrical issue.

[crimsontracer]

Well - I think im gonna just run my kat of a freakin cliff.

After thinking about it realized that buying a new CDI was premature. Decided to do the coil relay mod since it was only 10 bucks in parts. Runs good but same problem. Except now its constant. still running on 3 cylinders. Previously thought it was 2 but I was wrong.

#4 does not fire. and it has spark.

So I guess I'll tear into the carbs yet another fucking time. But I have no idea what it could be. I've been in the carbs more in the past 2 months than ive been in my fridge.

...fuck...+

[skjeflo]

Just a couple thoughts.

Have you checked compression?

Does the #4 header warm up if you hold the RPMs above 3-4K?

[92xjunker]

Just a couple thoughts.

Have you checked compression?

Does the #4 header warm up if you hold the RPMs above 3-4K?

+1 might be a good time to check that