no spark any suggestions

[judy631]

just bought a 79 xs11 special. my brother says it doesnt have spark cause he pull the wire.. cranked next to the plug and seen no spark.. he owns a ducati.. any suggestions on this matter thanks..

[79XS11F]

Pull the plug caps off the wires and cut off about 1/4 of an inch of the plug wire. Let those fresh cut ends sit on the head in a fashion that the spark can jump from the plug wire ends to the head. Turn it over and confirm spark or no spark. If you get spark thread the plug caps back on to the ends and test again.
Rob

[TopCatGr58]

Just a little bit more info. These bikes use a wasted spark system, 2 wires to 1 coil, both fire at same time, BUT both need to be in contact with the engine for the spark to travel from 1 wire, THRU the engine to the other wire.

IF both wires were pulled from the plugs so that the matching wire was NOT touching the engine, then you would NOT necessarily see any spark!

Also, check the fuseblock and fuses, pull them out, pull on them, glass fuses are fragile and easily corrode, break, same with the fuse holders. Verify that you are still getting more than 10.5 volts across the battery during cranking! IF the battery is weak, may crank engine, but not have enough volts to run the black box/iggy box/TCI!

T.C.

[The Lorax]

check your pickup coil wires, they're under the timing cover on the left side of the engine as you're sitting on the bike. gently try to stretch the wires, if they stretch easily, they're broken and need repaired, read the tech tips on how to repair them, not difficult, but a common problem. could also be the TCI box, don't know how to test that one or how to fix it (sad being I'm an electronics guy by trade, I just never dug that deep into it...never needed to) also read the tips on what to check on a bike that's been sitting a while. also, before you get too deep into it, check, clean ALL electrical connections, ESPECIALLY the grounds. you might throw a little dielectric grease in there with them as well, will keep the corrosion at bay. that should keep you busy for a while. have a nice day and ride safe

[The Lorax]

oh yeah, welcome to the forum, you might edit your profile to show year, model of your bike in your signature, it makes it easier when diagnosing over the internet to know which one we're dealing with, and put your general location in there, might be one of us close that can help....most of us will work for beer. again, welcome always glad to have our numbers increasing, have a nice day and ride safe

[judy631]

thanks

thanks for the info.. the other people said it ran sometimes and sometimes not.. will start with the fuses and connections it only has 13000 mile. but it sat in a shed .. bought it for 300.00

[The Lorax]

I'm leaning more towards pick up coil wires, then bad electrical connections elsewhere....likely a bad ground. have a nice day and ride safe