too much spark

[lisa]

I just bought xs1100, it will not start. Thing I checked was spark, and as soon as key is turned on spark plug has low constant spark, when I try to start it pulses higher and lower. Any ideas what would cause this?

[oldyam80sg]

Welcome!A little more info would be helpful such as year and model if you know it.That way we could maybe point you in the right direction.Did you check the obvious things like gas and fuses?Thank You.

[lisa]

1980 xs1100 special, still checking on rest of information from serial number.

The bike used to run but quit, the po replaced "brain" and gave up. It has been in storage for a few years.

The first thing I checked is the spark plug and it gives a contant spark with key turned on with out engine running. When the start button is pushed the spark plug pulses brighter. Is this normal without the engine running?

I gather more information on the bike. Thank you for the help. Lisa.

[Crazcnuk]

no, definately not.

Does it stop if you unplug the TCI? The coil(s)?

Does it do this for all 4 plugs or just 2?

In order for the coild to be putting out a constant stream of sparks like that either the pick up coil or the TCI has to be sending out a stream of pulses to tell the coils to spark.

[oseaghdha]

Originally posted by lisa
1980 xs1100 special, still checking on rest of information from serial number.

The bike used to run but quit, the po replaced "brain" and gave up. It has been in storage for a few years.

The first thing I checked is the spark plug and it gives a contant spark with key turned on with out engine running. When the start button is pushed the spark plug pulses brighter. Is this normal without the engine running?

I gather more information on the bike. Thank you for the help. Lisa.

Sounds like he used the Abby Normal brain.

[Toolmaker Tim]

Spark

I guess the first thing is do you have a manual? That is a good thing to have. Are your plug wires going to the correct plugs? Is the fuse block in good shape? Is it stock or a modified wad of wires? What is the number on the TCI. If you have that and some of the particulars about the bike (serial numbers and part numbers) some of the gurus on this site can give some ideas on what might be wrong. Are there any obvious wires patched in or hanging loose? The wiring harness is for the most part wrapped in black electrical tape. If it is unwrapped or has the odd wire wandering off into the ughknown, the PO might have done more than just replace the brain. To just make a guess, I'd say you have a short or fault in the pick up and it's telling the TCI that the engine is running when it isn't. That's just a guess though. Good Luck and congrats on your bike. Just keep giving the guys here info and they will help you sort through it all. Mine was a basket case when I got it with bent valves and gunked up brakes and carbs and it's running in spite of me or just to spite me

[planedick]

Location, location, location

If we knew where you are, what city, there might be someone local to you that is an XSive and might be willing to help. Most all of us are so inclined.

[prometheus578]

Ok, I want to understand what you're saying, so bear with me.
First, remove all four spark plugs.(and just for info.. what do they look like? Black and dry sooty, Black and wet sooty, or white/tan?)
Now, with the spark plugs back in their caps, lay the plugs against the head, but away from the spark plug holes. (don't want to ignite a hot jet of fuel)
Ok... plugs in their wires, lying on the head, with the Hex head part of the plugs touching the head so that they'll ground.
Now, turn on the ignition(Turn the key)
What happens?
__Nothing?
__Some plugs give a quick spark? (which ones)
__All plugs give one quick spark?
__ Some plugs spark and spark and spark?
__All plugs spark and spark and spark?
(Depending on the position of the crank in relation to the pick-up coils, sometimes a initial spark happens when you turn the key on. You can also get a quick spark when you turn the key off, as the electrical system powers down)


Ok... Now hit the starter button.
With the engine cranking... what are the plugs doing now?
Are they sparking every once in a while? (As the engine cranks over, each spark plug should fire once for each engine rotation.)
Or, are they producing what you've called a constant spark?(whatever that means?)

My thoughts are, at the moment, we may have a difference in terminology... What you're calling a constant spark... is a normal spark rotation.... it's just that the bike won't run.

As the bike has sat for several years...My initial thought is that the spark is fine, but you need a good carb cleaning. You may have put fresh fuel in the tank, but the fuel still in the carb bowls either has lost all it's "Umph!", or turned to varnish and gummed up the jets. In that case, you may be getting perfect spark.. but no fuel to run.
Now, I don't want to tell you all the potentially dangerous ways to test this, but I'll give you a simple test to try.
First, make sure the battery has a good charge. I can imagine that after all your cranking, it's in sad shape.
Anyway... use a turkey baster or figger out some other way, but here's the deal.
Put about a teaspoon of gas down each spark plug hole and quickly put the plugs back in and the plug wires back on.
Now crank the engine.
It should burp, fart, spit or something. Might even run for a few seconds.
If it runs for a few seconds(due to the few second's worth of fuel you put in), then it's a fuel issue we're chasing, not a spark issue.

[prometheus578]

Most all of us are so inclined

I'm more inclined if she's single... and has a good paying job!
(I'm assuming that Lisa is her name, not just the "name" of some guy's bike)

[strippedFJ]

Have you checked that the new brain was wired in correctly? Checked the rest of the wiring in the ignition circuit?
Is it both coils doing this or just one of them? Check this site for how to diagnose dodgy coils.

http://wiki.answers.com/Q/How_do_you...otorcycle_coil

Sounds like either the TCI unit has been bypassed, or the coil(s) have an internal resistance failure, such that there's a constant 'on' condition.

A brain failure could cause that condition, but I would expect it to more likely fail to ignite the coils. The fact that the spark is boosted when the engine is turned over indicates that the brain is, at least partially, working.

[mro]

low constant spark

Not something I've XSperienced before

Two little wires on each coil.
The one fromTCI, pull it off and see if it has continuity with the frame or engne.

If it's grounded all the time might be your problem.
Insulation broken and wire "shorting", TCI fried??

Engine starter draws a lot a power, XSpecially on the compression stroke which could account for "I try to start it pulses higher and lower" .


mro

[Toolmaker Tim]

The bike guys, th bike

Reading these post reminds me of why I'm married. They sound sort of.................desperate, shall we say

[mro]

originally posted by Mr Butts (Toolmaker Tim)
They sound sort of.................desperate, shall we say

Not deperate at all, just gave up while ago


mro
BTW, lisa has only 2 posts, Butt you have a bunch and are fair game

[strippedFJ]

Re: low constant spark

Originally posted by mro
Not something I've XSperienced before

Two little wires on each coil.
The one fromTCI, pull it off and see if it has continuity with the frame or engne.

If it's grounded all the time might be your problem.
Insulation broken and wire "shorting", TCI fried??

Engine starter draws a lot a power, XSpecially on the compression stroke which could account for "I try to start it pulses higher and lower" .


mro

The starters power draw would result in the spark droppng lower, not increasing to high then back down to low, which is what Lisa wrote. If the TCI was completely fried then there wouldn't be a strengthening of the pulse. Does a short on the coil -> TCI wire result in complete frying of the TCI on these bikes? If the TCI is partially fried then it could be holding the coils open, with increased pulses when the TCI properly fires.

The check you mention should still be the first thing done.

Just as an aside, I'm wondering if this condition would result in the air/fuel mixture igniting on entry to the cylinders? ie could it cause a flame front back up through the carbs? Or would the 'spark' be too weak?

[strippedFJ]

Re: The bike guys, th bike

Originally posted by Toolmaker Tim
Reading these post reminds me of why I'm married. They sound sort of.................desperate, shall we say

You got married because you were desperate?

Not a good look mate, not good at all.