Spark trouble

[scotthays5]

I have a 79 xs standard been riding her for 5 years now. Im not getting any spark. i changed plugs and both coil packs so where do i look now.

[TopCatGr58]

Hey Scott,

Welcome, and nice to see a veteran rider and not just a newbie with a barn find machine!!

Okay, first how old is the battery? How many volts is it putting out?
During starting, if dropping to 10.5 or less, the TCI black box will NOT work!

Secondly, your machine has the ballast resistor, are known to crack and break stopping current flow to coils. HOWEVER, the TCI bypasses it during the cranking mode, so if you are not seeing spark by laying 1 removed plug wire with a spark plug in it against the head while cranking, then the trouble is elsewhere!

Also, did the bike just die...like you road it okay, parked it and it wouldn't start the next time, or what exactly happened?

Do you still have the original fuseblock!? Glass fuses can look okay, but when you actually pull them out, they can fall apart in your hands, the ends can pull off of the fuses, the clips can fall apart from corrosion, wear, etc.!!

Okay, that'll get you "started" on your troubleshooting steps, check these out and report back with findings, the more info the better, don't worry about being verbose...more info is what we need for remote diagnostics!

[scotthays5]

i have a brand new battery just replaced this summer. my bike was taking longer and longer to start all year than she just stoped. i took out 1 plug did not see spark so i took the coils up to have them tested the 2-3 coil was bad so i bought diffrent coils tested good put them in and still have no spark,and the fusses have been bypassed with buss fuesses.

thank you for helping

[DiverRay]

Scott,
List your location and you may find some help nearby. T.C. has covered all the bases, but it's hard on the "step 1", because we don't know the full symptoms.
A Volt/Ohm meter is your friend! Use it as T.C. said to start looking at battery voltage, fuses, and power to the coils.
Welcome to the site!
Are the new coils the same as the old ones? the '78-'80 needed ballast resistors, newer bikes did NOT, and used a different coil.

[TopCatGr58]

Hey Scott,

Like DIVER said, back to the battery first. New ones have been known to go bad, and faults in the charging system can cause a good one to go bad as well!! The Reg/Rects are known to go bad, causing you to loose charging efficiency. You can also try to start it with a jump from a car battery, just make sure you connect jump cables correctly. Best to have car engine off, but has been posted that running won't hurt it either, YMMV!

Also did you get OEM coils..the 1.5 ohm kind, or aftermarket ones that might be rated at 3.0 ohms, or some other kind??
T.C.