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07 KLR Won't Start (Wits End)

6K views 20 replies 12 participants last post by  Fanbelt 
#1 ·
Hi everyone,

Can't believe I'm still fighting with this bike, but I just got it back from my local garage and no improvement. For $200, they told me I need a new front tire. I agree. But the bike still doesn't start with the ignition button.

When I push the button, the engine turns but does not fire. No big backfires either, just some little hiccups.

- Battery is new and charged.
- Spark plug is new and clean (when I pull it I notice it's wet, but it still arcs when held to side of engine)
- Gas is new.
- Carburetor has been cleaned dozens of times (removed, completely dismantled, passage ways and jets blown out with carb cleaner and compressed air)
- Vacuum slide diaphragm is new.
- Air filter clean
- Valves in speck
- Timing is correct (at TDC, marks on the cams are flat and facing the right way.
- Kick stand switch disabled.
- Compression test done at garage (they say 165lbs, although I thought it was impossible to do a normal compression test because of KACR, and even then, 165 sounds high)

Starter fluid does not get it to start, either in fuel line or through airbox.

Bike can be push started, and once it's running it runs GREAT. Never had so much power and responsiveness.

What in the world am I missing? I've been around the world on this bike and cannot dream of replacing it. But I do need it to run.

Please help,
-eric-
 
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#2 ·
Starter fluid does not get it to start, either in fuel line or through airbox.
If you have good compression and valve timing, then I'd think the only reason you wouldn't get it to start (even temporarily) on starter fluid is due to lack of spark.

Have you done a spark check?

Plug out, plug wire on, plug held against head for ground, spin the starter to see
 
#3 ·
Eric Swoyer,
Unscrew the spark plug cap from the coil wire & hold its bare tip about 7-8mm away from valve cover Bolt, to check spark Strength.

The system needs more strength when under compression. Even a very weak system may spark 1mm at atmospheric pressure.

Have you checked ohms resistance of exciter coil & both sides of ignition coil? Did you record your readings, or did the shop?

A push start would increase the exciter coil AC Voltage output above what is achievable by the approximate 300rpm of the starter motor.
 
#4 ·
Three maybe guesses.
Spark too weak.
Spark non-existent.
Short in the starting circuit.

If it runs OK when push started but won't fire from the elec button look for a short somewhere in the starting circuit. It may spark when the plug is out but earth out when re-installed. If starter fluid won't do it then the spark may be non-existent when the plug is installed.

Try hooking up a big car battery as if you were going to jump-start it. This may give enough oomph to get a spark. If this works the spark is too weak for some reason.

Some cars run an alternate wire which comes into play when the starter circuit is used. This handles battery voltage drop when cranking. No idea if the electro-trickery ignition system which runs a KLR does this but, if so, possibly something may be out of kilter there.

Hope that helps.
 
#6 ·
Low fuel level in carb. ?
Maybe have a check on neutral switch wire?
Do you have switch on prop stand ?

Am thinking you need to look at what is different when you push start to when you electric start.

I am more ok with the KLR600 so may be barking up the wrong tree.
 
#8 ·
Eric ... you mentioned that you can roll start the bike. Once it is running/warm, can you stop and start with starter? Is this a cold start issue or does the issue remain when it is warm?
 
#9 · (Edited)
Starter fluid does not get it to start, either in fuel line or through airbox.
Bike can be push started, and once it's running it runs GREAT. Never had so much power and responsiveness.
The question RE if it restarts hot is a good one, though it sounds like it never starts except by pushing.

I am fighting a tenacious intermittent/no start issue and am wary of giving advice right now--I thought I had this licked (and I still think I do!) but I also think I may have just fried a CDI in testing :( That or my multimeter pooped the bed at the same time something else went wrong. Seems unlikely.

Anyway, the two differences I see between bump starting and using the button are
1. As mentioned, the engine could be spinning faster and making more voltage at the exciter coil = stronger spark
2. The Y/B wire from the starter relay won't be energized if you're bump starting--this wire is the rogue connection to the CDI added on later bikes, and it's only hot when cranking edit: Jury seems out on exactly what this wire DOES.
3. Your thumb isn't physically pushing down on the starter button.

1. If you haven't already, pop the tank and measure AC voltage from the exciter coil while cranking--same place you measure resistance of it when it's just sitting there per Clymer. Disconnect both connections from the stator cover, which can be found up near the CDI / coolant overflow, so there's no wackiness getting to the CDI. I haven't found a concrete number on correct, but internet sources suggest 55-60v AC when cranking. If you're seeing substantially less than that, your CDI will have issue getting enough ooomph to spark in the combustion chamber even if you see a spark in the garage when the plug is pulled.

2. Try pulling the y/b wire from the CDI and push the start button. I would be amazed if it mattered, but it is one of the few places the bike could know that you were starting it with its own power instead of a push.

3. Make very sure the bike is in neutral and jump the battery hot to the lug on the starter downstream of the relay, or simply jump the relay itself. Can't hurt.

Curious to know what you find. I am waiting on a CDI and I'm going to hopefully have my bike together, then I'll update my own thread. The perfect is the enemy of the good and I should have stopped when the damn thing ran instead of trying to improve stuff!

Luke
 
#10 ·
. . . this wire is the rogue connection to the CDI added on later bikes, presumably to advance ignition a hair JUST while cranking.
When spark advance levers appeared on the steering columns of automobiles (yes, I'm THAT old!), in my memory, the spark was retarded upon starting (either hand-crank, or the more modern, "self-starter"). I'd welcome a correction to my already-proven unreliable memory, if I am in error (again!) this time.

:)
 
#13 ·
You are correct, while not that old, I did restoration work on several Model "T"'s and "A"'s and retarding advance makes the plug fire further BFTDC, less compression then, less effort on on the hand cranking..
 
#11 ·
As I understood it from Normk, the Yellow/Black wire did Retard the ignition spark during Electric Starting on a Gen 1.

I won't confuse the diagnostics with Tom Schmitz' issues from when he fitted a kickstarter onto his Gen 2. :)
 
#12 ·
And, checking it with an oscilloscope, it doesn't appear to do anything to ignition timing.

The only way I know to check for this is with a scope and I just didn't see anything.

I have said that I believe that the function of the Y/Bk wire is to disable an anti-kickback function rather than retard the timing.
Retarding the timing doesn't make much sense in the grand scheme of things.

The Y/Bk wire was added to the A4 (1990). The igniter was changed on the A4 and carried through to 2007. I believe that Kawasaki used/uses off-the-shelf components from Denso and the one they chose (or were able) to source for '90+ simply had an anti-kickback feature that needed defeating, thus the yellow wire.

But Norm said he checked it and it retarded the timing. Funny that nobody ever asked How? and Why?.
 
#15 ·
I apologize; I'll edit the original post. Still a valid point that energizing the y/b wire is one of the few ways the bike knows how it's being spun over.



Because I am both in the weeds on my own no-start issue and a generally inquisitive type: If the y/b wire defeats an antikickback feature (which I understand to mean: "With NO voltage on the y/b wire, the CDI will NOT spark below a minimum RPM") then how is it possible to bump start a gen 1 with NO functioning battery? I have started my 03 after the battery mechanically failed (plate broke loose offroad and the thing had 0 voltage) as well as jumpstarted it directly to the big hot lug on the starter using a large screwdriver and automotive jumper cables (which would not energize the y/b wire on the small side of the starter relay). If 0v on the y/b wire prevents spark, how could the bike start in those situations?

Not challenging, just trying to understand better.

Luke
 
#14 ·
ymracing, "retarding advance makes the plug fire further BFTDC, less compression then, less effort on on the hand cranking.. " "BFTDC" what??

"further BeFore Top Dead Center" would be more advance. So I must be mis-understanding.... And compression would NOT change, imo.
 
#16 · (Edited)
@ldeikis,

Good questions.

To the bump starting portion of the question, it is possible to bump start a Gen 2 with a very weak battery. I point this out because testing has been done that proves that the analogous wire in a Gen 2 does, indeed, defeat the anti-kickback feature in the igniter. That testing showed that the igniter needed to see more than 200rpm to make spark without the Y/R wire being energized. It seems that bump starting the thing easily generates over 200rpm at the crankshaft.

I would assume the same for Gen 1 vis-a-vis an anti-kickback function and bump starting.

The second part of your question is more interesting, and I have to admit that I have never investigated this. I will claim to have thought about it during my Gen 2 kickstarter escapades, which is the same as admitting I'm a lazy bastiche for never following up on the thinking part.

Here was my thinking, and I reserve the right to be wrong and to be corrected. I figured that a strong battery, as in the case of a jump-start from an external battery, would spin the engine at more than 200rpm. I never got out my handy optical tachometer and point it at the rotor because oil comes shooting out of that hole during cranking.

I will do that then next time I have the valve cover off - less oil flings off of the cam sprockets and it's easy to multiply the reading by 2. It will be an interesting data point.

What was not clear to me was why Denso would design the feature into the igniter, as well as a way to defeat it, and why Kawasaki would choose to defeat it. The prime time for a kick-back to happen is during slow cranking, as might happen during kick starting and with a weak battery. Kick-starting being pretty much passé, the driving concern for Denso to incorporate an anti-kickback feature would have been to protect the e-start components in the event of a low battery. Perhaps Kawasaki felt that the low battery issue was not that serious a concern and that their reduction gear mechanism would be enough to protect the e-start components in the event of a kickback.

Which is all a long-winded way of saying I am confused and conflicted.

It's also a long-winded way of avoiding having to answer your questions by saying "I don't know."
 
#17 ·
If the CDI allows spark above 200rpm regardless of the y/b wire's voltage--which would explain why we can bumpstart a gen1 with zero battery voltage, or with +12v directly to the starter--then wouldn't a healthy gen1 run and start just fine with or without that wire? I don't know what my bike turns over at when attempting to start, but it will be easy to know--the last time I tried to look, I had the harness all de-pinned so the tach wasn't getting a signal anyway and I couldn't record it.

When I finally get my bike running again I may also shoot a timing light in the hole in the stator cover with and without that y/b wire energized. I don't know if 3 degrees would be visible without a real scope though...

Luke
 
#18 · (Edited)
If the CDI allows spark above 200rpm regardless of the y/b wire's voltage...then wouldn't a healthy gen1 run and start just fine with or without that wire?
Yes it will, as will a Gen 2. And therein lies the conundrum of why did Kawasaki choose to defeat this feature so that an unhealthy bike (weak battery) could make spark a very low rpm. I simply don't know the answer to that.

...When I finally get my bike running again I may also shoot a timing light in the hole in the stator cover with and without that y/b wire energized. I don't know if 3 degrees would be visible without a real scope though...
Cha, dat's messy. With the bike running there is an amount of oil coming out of that hole that cannot be duplicated by the best projectile-vomiting-possessed-by-demon person. If any hole in the KLR crankcase is left open, timing inspection, rotor bolt, or oil filler, the displaced volume of the piston's downstroke creates an enormous amount of crankcase pressure with which to expel oil from said hole. I have to admit to having accidental experience with this phenomenon on more than one occasion.

It was this that caused me to ask the question of Norm, never answered, of how he happened to measure this wee bit of retard. If you look at a rotor you will find markings at 0°, 10°, and 30°; hardly enough granularity to discern a small amount of timing change even if you were able to see the markings on the rotor with a timing light.

When I tried to see the effect of the Y/Bk wire on the oscilloscope all I could see was that, when energized, it seemed to make the trace a bit jittery as if it were introducing some noise into the signal. I saw no timing retard.
 
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#20 ·
Hi everyone. Thanks so much for jumping in on this again!

Newest Update… IT STARTS!!

Here’s what changed:

1) Boston is 20 degrees warmer then it should be.
2) I’m holding in the clutch lever when cranking (with bike in neutral)

Clutch lever makes me suspect the neutral circuit. Although the plug sparks to the valve cover easily enough and the starter motor turns with or without the clutch engaged.

I also notice this: if I hold the ignition button (bike cranks and tries to start) then slowly pull in the clutch lever, there is a “dead spot” about halfway in. At this dead spot, the bike stops cranking, then starts again as the lever is compressed further.

Like it or not, I guess it’s electrical.

I’ll jump the switch in the clutch lever and see what that does, then start going through the three points from Ideikis.

Thank you guys so much. I'm crap with electrical so this might take a while. But at least the damn thing turns on :)
 
#21 ·
The clutch safety switch causes problems . I noticed on my 07 , I had to find just the right
position to hold the clutch lever in for the starter to engage. About midpoint. The PO had already
done away with the kickstand switch, and now I have 86ed the clutch switch. My bike is now
primitive, like it's rider.
 
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