really odd spark problem

[Guest]

I finally got my bike together with a new chain, both sprockets, and we reset the carbs. She runs OK but now I'm having a spark issue.

She fires up just fine and runs for about 15 - 20 minutes and then just dies. I checked the spark plugs and noted I'm not getting any spark. I put my hand on the ignitor box and the R/R to see if they had maybe overheated. both were cool to the touch. I let it sit for about 20 minutes and hit the starter again and it fired right up. It rant for about ten minutes and all of a sudden no spark again. It does this over and over. Anyone seen or had this issue before?

[Planecrazy]

Ok, Steve, I'm just going to throw this one out there, but what about a short circuit situation at the coils? Maybe one or both are somehow shorting out, overheating, and failing until they cool down. Did you check EVERY plug to see if the spark loss is across all cylinders?

Good Luck!
Steve 8)

[skreemer]

spark loss is accross all 4... though i did notice that the "2 and 3" coil got hotter than the "1 and 4" coil did... any way to test the coil? just an ohm test or is there a volt test of some kind I can perform?

[Planecrazy]

I'm not "up" on coil test procedure, but considering how many GS's you have sitting around I'm thinking maybe you should just swap out each coil as a test, and see if the problem goes away...

Look forward to the update, Pal!
Steve 8)

[skreemer]

heh the one that's getting hot is not the one I got from you. I'm wondering if the other one let go finally....

[Planecrazy]

hah ... I forgot that I gave you one in the first place... Still, I'd grab one off Greg's bike and see if the problem goes away. Then you know two things ... that the one you're swapping in works, and what is required to solve the problem.

If you really want to be funny, don't tell him ... then see how long it takes him to figure out the issue on his own (assuming the swap solves your problem) :twisted:

Good Luck, Buddy!
Steve 8)

[skreemer]

well Nerobro replaced the ignitor "blackbox" with the spare one I had and still no spark... he pulled the battery and it's drained... I must have killed it cranking the bike over so much.... I gotta get those carbs sorted out...

[skreemer]

thought I had the problem licked with recharging the battery... no go...

we cranked it over and she coughed a bit for not being started in a week and fired up. Idled realy rough but we knew that and were hoping to get that set up and fixed.... all ran fine till while fooling with the idle we killed it. cranked it over and over and no spark...

#1. all 4 coils go out at once.
#2. it's not the ignitor box I've had both on there neither worked... let it sit and they fired up.
#3. Mosfet? on the right side directly in front of the clutch cover. anyway to test it/know what voltage we should be seeing there?
#4. the wires run directly from this unit to the ignitor and then to the coils...

Anyone know a quick way to test for shorts or longs on the electrical systems on our biks???

[jimcor]

skreemer, just a long shot. Does your bike use the old glass fuses? You might have a main or ignition fuse that is getting hot and melting the solder at the end caps. The bike cools off solder solidifies...

I've had some weird problems because of those old fuses. I had some problems with my bike cutting out, talked to the service manager at the local shop and this is the first thing he told me to check. Nailed it.

[skreemer]

thanks for the hint when i get back home after work I'll pull the fuse cover off and check that right off...

anyone else? any and all ideas accepted.

[skreemer]

I checked the fuses and they were all OK...
So i grabbed the spare bike and pulled the hall effect sensor off of it (controls the timing a bit) it sits right in front of the clutch... where the points would be on an older bike....

Swapped the part and fired it up. The dang thing would run at 5K or 6K and that was it. If I closed the choke any bit past 3/4 open it would just up and die.

We turned the screws out 4 and a half turns and she settled in nicely. I'm betting I need to do a carb sync to make it "perfect" but it's pretty dang close right now.

Thanks for the tips guys.