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2004 DRZ400 will not start

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2004 drz "S" with 12800 miles. "E" gearing, rejetted with 3x3, otherwise stock.

symptoms before non-starting problem:

1) higher speed/rpm miss in 4th or 5th gear, around 50mph. i do not have a tach.

came home, from ride last sunday (oct 9th 2011) and dumped the float bowl to check for water in gas. none. checked for dirty filter, it wasn't. tried to start, no joy.

history:

bought with 8,000 miles, immediately realized the stator was not charging. replaced with new rickystator. ran fine until 1 1/2 months ago, began non-charging condition again. replaced with free-replacement from rickystator.

all electric connections have been cleaned, lubed, and reconnected.

battery replaced 1 1/2 months ago, no starting issues until this problem

battery shows 12.9V key off

battery shows 12.9V key on (give or take very little)

battery shows 12.64V key on starting

battery recovers quickly to 12.9V after starting attempt

stator charged @ 13.5-14V (LAST TIME IT RAN)

stator test of three yellow leads = good stator

stator test of output not possible (non running bike)

free power mod done

coil tests (cold) 15K ohm

spark plugs are new, gapped .031" ngk cr8e

spark is fat and blue, will bridge .400" gap from screwdriver to ground. or a finger, and that hurts, twice.

spark plug is wet after several attempts at starting

intake and exhaust valves within spec, iirc .004" IN and .008-.009" EX

cams appear timed correctly, chain is snug and quiet

TDC mark on flywheel appears to coincide with cam timing

manual cam chain tensioner installed 2 weeks ago

oil changed at or before 1,000 miles, suzuki filter, 20w50 castrol non-synthetic for summer

normal starting (cold) procedure:

full choke, blip the starter and she lives. drop to 1/2 choke in 20-30 seconds, idle 2-3 minutes, then ride. great performance from idle to redline, but i rarely rev it that high.

bike has been completely reliable other than stator issues in the past, and crappy gas.

I don't know how to disable the auto-decompress, and my compression gauge won't fit in the plug hole for the frame's interference. (no compression test other than thumb on the hole)

bike does not backfire, pop, or sound like any explosion is happening at all when attempting to start. will not start with ether.

I guess this is where I ask for help again ? :thumbsup:

Edited by ohgood
moooorrrreeee info

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i see you have spark.

i would try removing the gas tank & spark plug, dump an ounce or 2 of fuel into the cylinder thru the spark plug hole, re-install spark plug & give it a try.

warning: this can be a fire hazard. do this outside with gas tank & other fuel sources away from bike.

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To make an engine run you need:

Good spark: You confirmed you have a good spark.

Cams correct: You confirmed this

We can fairly safely assume the flywheel key is intact but you may want to check it. If it is, the spark timing is correct. If the key broke and the flywheel moved a little and the cams jumped, you'd still have a good spark but not running. You would have to have the cam chain jump and the flywheel move just the right amount to make the cams still line up so it is safe to say the key is intact.

That leaves us with compression and fuel issues.

When the bike cranks, does it have that characteristic 'chum-pf' as it cycles through compression? Did you inspect the compression release on the exhaust cam to ensure it is not sticking or otherwise broken?

You state you have a wet plug, so the engine is sucking in liquid. Is it fuel and not water? Did you drain the carb and tank and try new, fresh fuel?

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i see you have spark.

i would try removing the gas tank & spark plug, dump an ounce or 2 of fuel into the cylinder thru the spark plug hole, re-install spark plug & give it a try.

warning: this can be a fire hazard. do this outside with gas tank & other fuel sources away from bike.

Ok, tried it... 1ounce gas from the fz6 tank, on three seperate occasions. No noises that would indicate something good happening. Really surprised it didn't.

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Ok, going to pull stator cover and check flywheel key, along with cam timing again.

on a side note, folks that help are rare, folks that forgive and help again still rarer. Thanks erik, william, hats off.

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did it quit running while you were riding it? or was running fine one day,could not start it the next?

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did it quit running while you were riding it? or was running fine one day,could not start it the next?

Did not quit while riding:

Rode fine all morning, steady, constant stutter @ 50 or so MPH in 4th or 5th, came home, cleaned air filter, then no more starting.

No odd noises or lack of power while riding. Pulled fine, and could not duplicate the stutter in neutral while revving.

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With the pin where you can see it, gently lift the little weights from the cam, the pin should move.

Aha ! Very little peassure required, halves move out, pin turns to face the valve with the ground flat... understand the process now.

Mmm, looking at the flywheel I'm going to need a specialized puller if I want to check the key. Guess it will be a while on that.

Does it make sense that the flywheel TDC mark is centered in the inspection hole, cams aligned- that the flywheel should be timing correctly = not a valve timing problem ?

Edited by ohgood

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todays summary:

checked all connections, again

checked auto decompression mechanism- pretty neat, glad i understand how it works now

checked cam timing, again

dropped in a new coil, new plug

checked fuel flow, yes

checked for spark, nice, big fat blue spark

checked for vacuum, yes

tried starting until the battery sounded tired, let it rest. will put back on tender tonight.

sounds: normal, just like every other time i've hit the starter except there is no wonderful sound of ignition. no wonderful sound of the bike warming up. no wonderful sound of fun about to happen.

occasionally the 'fwap- WOOSH' sounded a little different. that's about it.

had a thought while i was staring at the bike:

if the crank key had sheared, and the flywheel spun enough on the crank to prevent starting (spark timing), it would show in the relationship of the flywheel to cam markings.... IF I were to assume the chain had jumped time, and re-adjusted it without realizing the flywheel key had sheared, the very next rotation would have spelled disaster for the head/valves. hmm. i'd bet someone has done just that.

well, that's it for this week i guess, unless anyone has a suggestion or three.

:thumbsup:

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The fact that it started to fail when riding makes me think ignition. Very hard to diagnose. Try disconnecting the 3 yellow stator wires, then try to start it. Sometimes a stator failure can interact with the ignition pick up.

Remove the stator cover and inspect for mechanical damage.

Test compression. Yes, I know the auto decompression with give low compression but you should still see 100psi or so at cranking speed.

You can jumper on a car battery for more cranking speed and longer battery life. Just don't over crank it and burn up the starter. Let it cool.

Do you have an old stator to try? Even if the 12 volt generator part is bad, if the ignition pick up are good it is worth a try.

I think you are fine for the flywheel key and valve timing but have you checked the primary dive nut? Possibly loose but not yet sheared.

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You are correct regarding the cam timing/flywheel relationship.

You made no mention of having drained the carb and fuel tank and refilling with new fuel.

I'm afraid to pour this gas into anything other than the creek or the lawnmower... should try a fresh tank this afternoon.

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The fact that it started to fail when riding makes me think ignition. Very hard to diagnose. Try disconnecting the 3 yellow stator wires, then try to start it. Sometimes a stator failure can interact with the ignition pick up.

Yes, I've removed both the stator and the RR from the starting equation as a test. No difference.

Remove the stator cover and inspect for mechanical damage.

None.

Test compression. Yes, I know the auto decompression with give low compression but you should still see 100psi or so at cranking speed.

I'm in process of hunting down a compression tester that a) works :thumbsup: will fit in the gap on the drz. Mine is broken.

You can jumper on a car battery for more cranking speed and longer battery life. Just don't over crank it and burn up the starter. Let it cool.

Yep, I've tried using the 1000cca battery from my old truck, both with and without the stock drz battery. I've started the bike enough for the starter to feel warm, I would assume 110F or so. Not uncomfortable for the inside wrist to touch. Then cool, repeat.

Do you have an old stator to try? Even if the 12 volt generator part is bad, if the ignition pick up are good it is worth a try.

Yes. Actually I have two others, both WERE GOOD FIRING but non-charging stators. They did not start the bike in this test. I emailed rickystator for an approximate coil resistance on the pickup coil, 500ohm was what I was quoted. All three stators have a pickup could with similar resistance. This is between the green and blue wires, on their stators.

I think you are fine for the flywheel key and valve timing but have you checked the primary dive nut? Possibly loose but not yet sheared.

I haven't checked it since I bought the bike. I suppose it's about time again. Don't know if they're prone to loosening over time myself.

Going for a long ride on the FZ this morning to clear out the cobwebs and try to soak up some positive sunshine. Will start wondering on the DRZ this afternoon, and well into the night I'd imagine.

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Did you check for fuel to carb (petcock fuel valve clog?). Pretty simple to check. Set the petcock to prime and open the bowl drain. If the fuel stops flowing you have you answer. Happened to my brothers bike last year turned out to be the fuel valve.

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Assuming all testing done is valid (not a flame, but basing opinions and suggestions on “known” only works with the assumption, the data is valid)

It really is pointing towards a bad source coil (the stator).. or a flywheel that is not keyed to the crank correctly causing good spark from a working ignition system, but at the WRONG time.

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Did you check for fuel to carb (petcock fuel valve clog?). Pretty simple to check. Set the petcock to prime and open the bowl drain. If the fuel stops flowing you have you answer. Happened to my brothers bike last year turned out to be the fuel valve.

yes, this was one of the first things (and ocasionally retried) I did, as I assumed there was water in the gas, or a flow problem. not an issue.

Assuming all testing done is valid (not a flame, but basing opinions and suggestions on “known” only works with the assumption, the data is valid)

understood

It really is pointing towards a bad source coil (the stator).. or a flywheel that is not keyed to the crank correctly causing good spark from a working ignition system, but at the WRONG time.

the source coil tests good (ohm'd per rickystator's tech suggestion that it should be around 500ohm) the key question is still up in the air. hopefully will have a flywheel puller fabbed up next week. ya, i'm leaning towards the fire being at the wrong time also.

Hmmm, I have the same problem

if you'll pm me, i'll keep record of any progress and pm you back if/when i find a root cause and cure. your reply is also one of the reasons i'm trying to find the root problem and the fix here, on thumpertalk. i don't know of a mechanic local to me that would be able to diagnose the problem and fix it for less than the price of buying another engine, or i would.

today i tried fresh gas, a few failed starts and no pop, no sign of combustion at all, just as always since the problem started.

then i removed the flywheel nut, hoping to be able to see if the key was deformed or not, but it's not visible without removing the flywheel (tapered fit I guess?) so I employed my $5 rubber strap wrench on the flywheel and torqued the nut back to 72.5 ft/lb.... very surprised the strap didn't slip. yay !

this is turning into quite a adventure.

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