05 Preddy 500 staring issues.

[TRXRacer1]

I'll start off with it's NOT the valves. I've already double checked that and shimmed accordingly.

Are these super sensitive to voltage? If this thing isn't pushing 13 volts when I start turning it's not happy. Seems like I have a good chance starting it when the trickle charge has been on but without it's a crap shoot. It's a new battery too that works perfectly fine. I pulled it and ran it in another quad for a while to check it out. The charging system is working fine too.

Also I can be in neutral with the indicator light on but if I don't pull the clutch it won't start turning over. I can let go of the clutch once it is turning and it continues just fine. Without initially pulling the clutch the neutral indicator light dims and nothing happens

As for Jetting it's about spot on.

Any ideas that don't relate to a bad battery, valve adjustment, spark plug or jetting???

[GE4x4]

Starter relay?? Battery termanials clean and tight? Coil?

[TRXRacer1]

Maybe.

Another weird thing going on is that it won't start running if the starter is turning. You have to spin the motor until you get a good pop and then quickly get off the button for it to fire up.

[TRXRacer1]

Nothing? :(

[katch26]

have you checked to see if the starter is actually tuning the motor over?

[TRXRacer1]

Originally posted by katch26
have you checked to see if the starter is actually tuning the motor over? Seriously? :mad:

[katch26]

it has a clutch safety switch......its not like a honda that will turn over without a key
theres a lot of things it could be. Yes it needs a strong battery especially if youre pushing hi comp or big bore. It could be the timing key or one way it could be the throttle cable is too loose or too tight (another sensor there). If the timing key sheers it can blow the one way which will fuse it to the crank and when that happens it could be off time slightly, as dumb as that sounds its happened to me and I chased it for awhile before tracking it down there. The factory filter clamps are junk and often come loose letting in more air and will have trouble staying started.

[TRXRacer1]

Originally posted by katch26
it has a clutch safety switch......its not like a honda that will turn over without a key
theres a lot of things it could be. Yes it needs a strong battery especially if youre pushing hi comp or big bore. It could be the timing key or one way it could be the throttle cable is too loose or too tight (another sensor there). If the timing key sheers it can blow the one way which will fuse it to the crank and when that happens it could be off time slightly, as dumb as that sounds its happened to me and I chased it for awhile before tracking it down there. The factory filter clamps are junk and often come loose letting in more air and will have trouble staying started. Clamps are good, no engine mods, the thumb sensor is taken care of. I'll look into the flywheel crank relationship. Is saying a Honda will turn over without a key what you were meaning to say?

[katch26]

yeah.....every honda Ive had or ridden it would do everything except start even without a key. There are 2 places to check on the thumb throttle (just occurred to me). The cable slack like we talked about and under the throttle cover. If it gets moisture it will also also want to shut her down.

[katch26]

any update?
mine just started doing the same thing last weekend. I think Ive narrowed it down to the ignition box. It never occurred to me to ask you what kind of box you have?, aftermarket?, those cheapo procom boxes usually make for a hard starting machine. Apparently my super expensive vortex has suffered the same fate :( ......have to send it out for reprogramming

[TRXRacer1]

I keep a little auto charger on it now to keep the battery fresh while parked and it fires right up. Simple enough solution for now.

Stock everything on this quad except for the full exhaust. Sorry to hear you're having issues too now.

[katch26]

thats ok, this is literally the only (albeit persistent) problem Ive ever really had with the bike and if it ends up being self inflicted Ill have to kick my own ***. Glad yours got straightened out and for it to be that simple is such an added bonus!

[notch johnson]

I think you have identified the problem is still voltage related. You mentioned occasionally if you let off the starter button, deactivating the starter at the right moment, the engine will fire.

When you do that you are removing a significant voltage load, raising the voltage for ignition related components.

I think you need to perform the following tests to verify the ignition side is receiving the correct voltage.....

"CRANKING OUTPUT TEST
WITH PEAK READING
VOLTMETER" as outlined in the service manual. It states the following.....
The following peak voltage tests will measure the
amount of output directly from each component. A
peak reading voltmeter must be used to perform the
tests. A variety of peak reading adaptors are
commercially available for use with the Fluket 77
Digital Multimeter (PV--43568), which will allow peak
voltage tests to be performed accurately. Follow the
directions provided with the adaptor. All
measurements are indicated in DC Volts. Readings
obtained without a peak reading adaptor will be
significantly different.
Test output from the CDI and pulse (trigger) coil and
compare to the table. The following measurements
are obtained when cranking the engine with the
electric starter, spark plug installed. The starter
system must be in good condition and the battery fully
charged.
200 Watt 4 Stroke DC/CDI Ignition
Test Connect
Meter Wires
To:
Reading
(Without Peak
Reading Volt
meter)
Pulse (Trigger) White/Red
and White
3.3 DCV

CDI OUTPUT TEST USING
PEAK READING ADAPTOR
Re-connect all CDI wires to stator wires. Disconnect
CDI module wire from ignition coil primary terminal.
Connect one meter lead to engine ground and the
other to the ignition coil primary wire leading from the
CDI module. Set meter to read DC Volts. Crank
engine and check output of CDI wire to coil.
Reconnect CDI wire to coil.
Output w/ Peak output tester
130 DCV
Average Output w/ Digital Voltmeter
20 DCV

*** the peak output tester is best, however the ratings via a traditional voltmeter should also work****

These tests should validate if your electrical connections are good. If anything fails clean your connections and grounds.

If that doesn't correct the issue then replace the component that continues to not output the correct voltage.

If after running the atv the battery always remains at 13v then it is being charged and is considered at fully charge anything over 12.6v so I would rule the charging system out.

Having to hook up a charger to give the system a voltage boost seems to indicate you are not getting the level of voltage needed at the ignition components if all else like timing and spark has been checked.

[TRXRacer1]

That is some intriguing advice Notch. Thank you very much. I'm on a couple other machines right now but when I run these tests I'll post the results.

[notch johnson]

Oddly enough my atv was in the shop for a similar issue. I just got a call this morning it was ready to be picked up.

Like yours, my cams checked out, battery seemed okay, etc.... I even tried these tests and it seemed okay to me.

I dropped it off at my mechanic and I would be damned..... the fusible link (small black wire off battery) was faulty. He said it looked like someone tried to repair it in the past (I bought my 03 used). I suppose this allowed the voltage to appear okay but possibly could not supply sufficient amperage.... not sure. I checked everything possible and all checked.... guess that is why mechanics are the ultimate source!!

Maybe try to bypass this wire and run a wire from the battery to the three red power wires that connect to it by the starter solenoid. My mechanic replaced the fusible link with a circuit breaker and traditional wire.

$140 and all is well now. Fortunately he only charges $35 an hour and provides estimates up front on how long it should take.