loss of spark

[jimg1au]

hi
just finished my 2nd 2nd gear fix in 7 days,started bike up then it stopped.no spark.this bike had been sitting for a few years in a shed.it is a 1981 xs1100rh.any clues of were to look other than the cdi box.the fuses are all ok and when the on/of switch is moved it stops cranking when starts when moved to the on position.all lights work as they should.

ps
my 1st 2nd gear fix works a dream.great to have 2nd gear back again.
thanks
jim garvey
1 x xs1100h
2 x xs1100rh
1 x it400

[Steve Linderman]

No spark...

Jim,
Some of the North American versions have a 'secret fuse' on the '80 + models...look under the left side cover...(the locking one) if there it will be forward of the battery, above the side cover locking mechanism...and it should be a red wire with a black rubber cover, inside will be a fuse...and room for a spare...this 'secret' fuse has confounded many an XS 1100 Owner!
You will ride it into the garage...and the next time you try and start her...nothing!!! (even 10 minutes later!)
EVERYTHING will work...it just won't run...even heard of a few guys buying $500.00 'brain boxes' that didn't 'fix it'
OOPS!
Half the Yamaha mechanics didn't know about this fuse! and the way to know if they do is...just say 'secret fuse' if they say "WHAT secret fuse?" then you know they haven't a CLUE!!
In addition...I know this ignition system needs a certain amount of juice to 'tickle' the ignition...a 'weak' battery will 'spin' the motor fast enough to accomplish this...but then the headlight tries to light...and robs the juice...
But from what you're describing...I'd look for the 'secret fuse', first.
Good luck, keep postin'... and let us know...

"When are you ever gonna' grow up?"
(My Mother Cir-2004)

[TopCatGr58]

Hey there Jim,

You say fuses are good, but did you actually pull them to inspect them, vs. just looking to see if they appeared intact? Checked for voltage on both sides of the fuse holders! That secret fuse I thought was a MAIN fuse, and if it was bad, nothing would work?
The wiring diagram shows power from the battery FIRST going thru this fuse before it goes anywhere else, the key switch, back to the FUSE block where it then powers several other fuses!
The later models still used one of the fuse box fuses for the ignition circuit! Also get some electrical contact cleaner and check all of the connectors in the ignition circuit, included the ones for the TCI! Good luck!
T.C.

[desert1]

resistance

Unhook the 4 pin plug at the CDI box and check the leads going to the pick-ups for the proper ohms value, its about 700 ohms.....each set of leads corresponds to a set of points. Look for a short and or a break in the wiring to the pick-ups......also could be corrosion in the connections........check your coil leads as well.
All I can offer for now. Good luck with it.

Bruce

[jimg1au]

no spark

today i swaped the cdi to my other bike it ran fine so the fault must be in the wireing.will continue to look.

[Steve Linderman]

NO Spark?

Hey, Again...
So since we're all training for the plug-n-unplug Olympics... did anybody think to grab a little tube of "BULB GREASE" (Wal-Mart 80 cents) and with a toothpick (or like type item) 'smear' a LITTLE of it on ALL those (ELECTRICAL ) connections we've been playin' with?
'Ya only gotta do it once' and since it LASTS forever...you can now sleep peacfully knowing:
1. some guy in the future is gonna get a buncha' gooey crap All over himself
2.YOUR electrical connections will:
a. stop corroding IMMEDIATELY.
b. not be as bad as everyone elses.
c. never corrode again (even under water)
(does water get on motorcycles )

But you mechanuts aughta know better...oh...and those pesky fuses...that you WILL be replacing with the blade style (sooner or later)
go ahead...feel free to 'smear' some on them too.
And...yea...when ever you change a bulb...that's right...get your 'little tube' out (it SHOULD be in the toolbox) and DO IT !!!
Every time I ride in the rain...or 'pressure wash' the bikes...I HAVE NO (little ) FEAR.
Just thought I'd mention it...

And it gives you something to do (instead of curse) while you're plotting your next move (looking for the fuses to your Dynamite)
But in any case...there's always that guy (in the future) with gooey crap all over himself, to consider.
Good Luck, with it, keep postin' & please let us know.

P.S. (dumb Q.) have you tried to 'verify' spark IE: pull spark plug, put back on wire, then trying it?
if you have a battery charger...hook that up and set it to 10amps, then watch for spark...that should be enough to 'create spark'
and help 'prove' a few things.