Ignition woes..

[jmutiger]

Went for a ride in the rain yesterday.. Bike was running without punch, like it usually does in the cold rain.. I thought it was carb icing, but after it died, and wouldn't start, I took apart the carb on the trail, and it wasn't iced up.. Couldn't get it started, plug wasn't fouled (obviously fouled).. Still have to diagnose the problem properly, but any suggestions.

1994 KDX250.

Jon!

 

[canyncarvr]

If it commonly runs poorly in the cold, maybe it's too lean?

I completely wore out my kicker trying to re-start my bike on rides after short stops. It was a common occurence until I realized that just a bit richer on the AS (in) made a treMENdous difference.

Went from kicking until I was blue in the face to one-and-go.

But...I DO still have the wonky kicker :(

 

[David Trustrum]

Well possible but if not:

Do the simple stuff first. Sparkplug, Sparkplug cap, clean or replace airfilter (replace by now) Check that the coil is grounded properly. (clean connector contacts, check with meter etc).

I always use the marine spark plug caps as they are waterproof & fairly cheapish but also the spring design doesn’t get eaten by vibration as the cheaper caps do esp the ones that have a spring against the bare thread.

PS did some dyno testing out of idle curiosity & found some caps were slightly better but probably only relevant on weak ignitions. The Marine cap was good.

The HT wire might be tracking in the wet as well.

Once a plug fouls it may not recover properly. Out in the open it may spark well but in a combustion chamber may just foul up again.

 

[jmutiger]

Well,

I solved the problem, but made another one..

The problem was simply a bad plug (thank god).. But after getting dirty with the bike, I decided to install my electrex coil (70W lighting coil).. Having never attempted this before, maybe I should have NOT tried it..

Here's how it went.. Got the flywheel off, after punching myself in the face and knocking myself onto the ground (the first removal of the flywheel was extremely hard).. Then I'm faced with 2 coil type things, of which I'm not 100% which one to swap out for my replacement.. I choose the lower one, which was the dinkier looking of the 2 (I had to remove the stator plate), and didn't even think to mark where it came from for timing).. Then I cut a wire, take off the coil (the crappier of the 2 on there), and proceed to install the new coil (lighting).. Put it back together, as best as I can.. And then it doesn't fire..

How do I time this thing? Did I swap the wrong coil?

Thanks,

Jon!

 

[canyncarvr]

sunuvva bi.....

DANG...can we turn back the clock?

Note the colors of the wires, and you'll tell (easily by now) that you sure as heck did the wrong one!!

This is based on: My '00 200 lighting coil is on the TOP. AND, looking at:

http://www.buykawasaki.com

for a '94 kdx250 generator, it's the TOP coil that looks like the lighting coil to me.

Still, the colors of the wires will tell you for sure. What...it's yellow off the top coil, right? Look at your headlight or light switch. Yellow, huh?

AND...the sparky coil is epoxied and covered, the lighting coil is simply varnished transformer wire.

There are going to be marks on the stator plate and the case for timing. In most cases the center mark will be used for 'standard' timing.

To tell for sure, you'll have to rig up a timing light with a duplicate mark on your flywheel or use the standard method of measuring spec distance from TDC to align the plate.

Shoot...just align the middle mark and go!

Torque the flywheel to spec!!! Use loctite (thread sealer). It's not hard to NOT get it tight enough (considering that the whole engine is hard to keep from moving), and then the woodruff key is going to shear at the MOST inopportune time!!

An air tool makes this whole process a snap. Or...an electric impact will work, too.

sorry :( You kinda stepped in it!

 

[jmutiger]

THANKS!

Thanks for the info.. Guess I'm gonna have to ATTEMPT to get that coil back in there, and take the other one out.. I'm an idiot.. I'll admit it.

Thanks for the info, hopefully I can get it going tonight.

Jon!

 

[canyncarvr]

A couple of notes on reattachment

Do it up right!!

Solder the wire connections. Use shrink wrap over the connection. THEN silicone the whole mess if you can.

Consider that the connection lives in a hostile environment....heat, cold, vibration, moisture. Everything that makes electrical connections die!

Cheap it with a crimp connector and some electrical tape and you'll be sorry!!

...well, sorrier?? :(

Might as well laugh at it!!!!! ;)

Good Luck!!!!!!

 

[Gamb8]

Hey canyncarvr,

"Cheap it with a crimp connector"??

In the school I went to for electronics on aircraft, granted we fly a little lower on dirtbikes :confused: , I was taught solder and crimp connections. If a solder joint is done correctly it will be equivalent to a crimp in regards to conductivity. But a solder joint is easy to do wrong and then it wouldn't be as good.

I definately agree with the shrink wrap and the silocone!

 

[David Trustrum]

& you will have also learnt that a good crimp connector is far less likely to fatigue that a solder joint in this environment.

Having said that the cheap insulated auto store crimps are hideously unreliable & shape in a crescent when crimped meaning they always get loose as the wire works to the edges. Whoever designed them thinking they were a good idea should be shot. Find a good foldover crimp tool & crimps & they will make all your connections likely to survive. Utilux is a good place to start. You can cut down bullet connectors for permanent connections just using the crimp part of one connector.

PS think of the lighting coil providing low voltage but requiring lots of current, so needs thick windings.

 

[canyncarvr]

Gamb8:
Yep...cheap it... AND YOU'LL BE SORRY! And I was most certainly referring to the connectors mr. trustrum is talking about.

I was AMRIP certified myself (avionic module repair). I'm not of 'The Bigger the Blob, the Better the Job' club.

A bad crimp job is going to be a problem just as a bad solder job....the latter having higher potential for problems/damage.

I think the original coil is soldered.

My point was to avoid having a couple of wires twisted together and some vinyl tape slapped on the 'connection' :(

 

[Gamb8]

I see said the blind man to the deaf man on the telephone.

Info is a good thing! thanx.