Spark question

Hi,

My R recently became very hard to start, and now won't start at all. I pulled the plug, grounded, and kicked her over to see if I have good spark. I don't appear to. The spark, when it shows up, appears weak. Shouldn't the spark show up on a regular (once every so many turns) basis? Sometimes I don't see a spark for many kicks, then it may show up for a few kicks in a row. Puzzling? Any ideas?

TIA,
ACE

Hi should spark all the time when kicking over, nice fat blue spark....anything else and yu will struggle. Pop a new plug in for what they cost then after that start working your way back to the coil check earth on frame etc.

Tsk......
http://www.thumpertalk.com/topic/1207829-01-xr650r-spark-question/

Sorry ... I do appreciate the response, but I also try to get as much info from applicable sources as possible.  Granted, this is the authoritative XR650R site .

Thx,
ACE

BTW, a new plug acts the same as the old, dim spark and sometimes multiple kicks before a spark ... so it's on to more t-shooting ...

Check the plug cap and earths as I mentioned before, also the connections back at the ECU under the seat and also check your kill switch isn't going to ground....

ive had that kill switch wire pull apart before, took abit of re-routing to gain some slack

It has been a while since my post about this, but I finally got around to t-shooting. In the process, I've removed all wiring except the bare minimum needed to start/run the bike.

As it turns out, the guys at my local shop knew what the problem was ... the stator (alternator). I guess the winding that feeds the CDI box, or the pulse generator, went bad. I swapped my upgraded stator out with the one that came with the bike when I bought it, and I got a good spark again. It's a shame, the new stator was a fairly new Ricky 200W dual output unit. I will replace the old stator again as it doesn't look real good (lots of rust covering one side). Not sure if I should use Ricky again, or go with Baja Designs. At least she starts again.

Now I need to re-wire the entire bike. The old wiring is somewhat crappy, and I may be taking a trip with her to the mountains in southern Colorado this summer ...

Thx,
ACE

I would re-wind the Ricky 1 yourself....nothing to lose ?....and replace the loom

Ace,

rust on a stator is not a problem.
In fact, on our bike this is almost a good sign, as the stator clearly runs dry - which it is supposed to do! If one opens it up very little oil may be found, the result of a sweating oilseal of the crank.... but if you find lots of it then that seal has gone, and you'll need to replace it!
The XRL (and CRF230 etc) run wet stators, oil circulates in it - for cooling, this works like an oilcooler. The R does not have this, it doesn't need it - for various reasons but the main one is that there's no power loss/friction, this is a racing bike after all.
However, this also means that this compartment is not cooled well, and consequently a stator - read large aftermarket unit - will heat up quite a bit! The OEM stator may be a bit small (2 sizes exist btw) but I've always thought 200W is pushing it heat-wise, and I get this sortof confirmed by reading about failures of them.
There's smaller one's out there, 150W or thereabouts, and you may want to get one of these if you need a bit more electrical oomph. Or, quite like Mauser said, wind one yourself.
However, your prob is the ignition, and I'd not wind these coils (they're dual adjacent coils) myself but would rely on a Honda's OEM stator, for reliability reasons - which this thread proves, the Ricky-one has failed you.
Best of luck!

Just to keep things alive, would I be right in thinking that heat will only be generated within the stator itself when producing power ?....the load on the "system" causes the resistance within the windings within the stator and as such turns this into thermal heat ?. If room dictated we could have large coil wires they in-turn would have a lower resistance and would get so hot...but due to space and needed "X" numbers of turns to create the coil field we have to use small diameter wires

Mauser wrote:Just to keep things alive, would I be right in thinking that heat will only be generated within the stator itself when producing power ?

Yip, correct, you clearly paid attention during your physics classes
Behind the stator-cover 2 types of losses occur: mechanical & electrical.
The mechanical part is the whirling of the stator in the enclosed air, very little hence best to ignore it.
The electrical part consist of various things, largely the efficiency of the stator (I'd hazard 60% effective hence 40% losses, and take the electrical output as the 'given' part) as well as the electrical losses (this IS different than the efficiency) which basically would be the Ohmic losses, the stuff will heat up ...... that is, if a current-demand exist ie the lights are on etc.

The thermal loading problem of a 'larger capacity' stator is compounded by the fact that the total surface area of the std stator is only a tiiiiiny bit bigger for a 'bigger' stator > it has to cool off to the surrounding air via the same surface-area (for simplicity let's ignore the heat-loss/cooling effect which is a result of conduction through the mounting points to the engine itself pls).
So, a bigger stator will get hotter than the std one, of course only when they're loaded to their capacity.



Oh, just in case some scientists/nerds read this and wholeheartedly disagree with my glossing-over some other thermodynamic happenings: yes you're right, now zuddup

Well, thanx for the follow up info, much appreciated.

ACE