xt600e starting problem

[guest1518]

I am almost finished a project where I have fitted an XT600e engine in a SRX frame.  I cannot get the thing to start.  It turns over nicely due to a new battery, the carbs have been cleaned out, and will need adjusting once I get the bike running.  All the wiring is done and everything works, the sidestand and clutch switch have both been bypassed so there are no issues there.
I have removed the spark plug and tested it for a spark, and when I press the starter the engine turns and produces a single spark, and no more while the engine continues to turn.  I'm convinced the problem lies there, but I don't know where to go from here.
Can somebody help.

[Richard]

Fresh fuel ?  Those engines hate anything older than about a week in the float bowl.

[guest1518]

thanks for reply Richard, I bought new fuel last week so it's not that.  I'll keep that in mind though.

[Richard]

May I suggest draining what is in the float bowl though - if using the twin carb set up there is a screw in the bowl.

Choke stuck ?

Fuel is reaching the carbs ? 

[guest1518]

carbs are all overhauled and ok, petrol is getting into engine and making plug wet.  I've even taken the carbs off my SRX and tried them.  I suspect the single spark when turning the motor over is a clue to the problem.

[Steve H]

What electrics are you using ? Are you using the XT600E CDI / alternator combination and if so are you also using an XT wiring harness ?. The wiring is quite different between the kickstart SRX engine on the electric start bikes, are you sure you have it correct ?.
What coil are you using ? I know that the SZR660 uses a different coil from that fitted to a kickstart SRX.
I suspect you are right in that it sparks once and then gives up is significant. In some ways it seems the wrong way around I would expect it to turn over at least one to build up momentum and then spark.

[guest1518]

thank you for your interest in my problem Steve.  I broke a 2003 XT600e to build this bike.  I am using the wiring and all the electrics from the XT.  I didn't hear the bike running before I bought it, but was assured it runs, but then people like to tell you what you want to hear.  It's possible that it had a pre-existing starting problem that I now have to sort out.

[Steve Lake]

I agree with you & Steve (H) , but as I'm not up to speed on XT's, difficult to suggest where to start... does the XT600 use a CDi unit?
if so , any chance of getting hold of a spare to try?
the wiring on the srx's I've rebuilt (8 & counting) can be a bit tricky, especially the connections to the CDi unit, it sounds to me that the connections from the stator to the CDi unit may be iffy or incorrect or the pickups may be faulty (these can be measured for resistance, I think, on the srx the source coil should be 84 - 156 ohms, the pickup coil should be 92 - 138 ohms.
ignition coil readings are .. primary 48 - 72 ohms, secondary is 5.2 - 7.8 Kohms)

also replace the cap/suppressor & plug..

I'm assuming that the Xt does not require battery power to achieve a spark, just to turn the engine over, so I'd expect to see a spark frequently, i.e. every stroke or every other stroke (some systems spark on every revolution with every other spark being reduntant)

hope this helps, but bear in mind that the meter readings are for SRX... but I'd expect similar readings for the xt.

[Steve H]

My understanding is that,unlike the twinshock SRX,  the XT600 electrics need a 12v feed. It might be worth measuring the voltage at the CDI to see if it is dropping whilst the engine is cranking over, you may have a bad earth which is causing the voltage to drop below the CDI's operating voltage.
Just a thought

[Richard]

Have you sorted it then ?

[guest1518]

Hi guys,
Problem still exists, carbs have been eliminated, I tried xt carb on my srx and it worked perfectly. I bought myself a multimeter and tested the ignition circuit and all was within the recommended range.  Everything points to the TCI unit, which costs an arm and a leg, and I can't find out how to test it. I am very reluctant to buy a new one without knowing for sure that it is indeed faulty

The single spark when I turn it over is white, it looks strong but the research I've been doing into this says that it should be blue.  Maybe that's a sign that the TCI is faulty. Hopefully someone can advise.

I considered shelving this project and using my SRX for this summer, but the kickstarting made the injury on my knee flare up again reminding me why I wanted an electric one in the first place.

Thanks for helping me, and I will keep at it until it's running, and will be grateful for any suggestions that will make this happen.

[themoudie]

Aye petefabz,

This maybe of assistance and may make more sense to the electronic minded on the forum. 

XS650TCI_link

I have to say that I am biased towards points, but have a Maplin system lined up for the Duke, once the points are installed. This will use them as a 'switch' rather than carrying the current.

Hope you can get something sorted out.

My regards, Bill.

[Steve H]

Did you try measuring the voltage to the ignition unit whilst you are cranking it over ?. If you have a poor earth it may be dropping to low for the ignition unit to function correctly.
Ignitech have a good reputation for aftermarket ECUs http://www.ignitech.cz/en/

[guest1518]

hi guys,
my compression tester arrived from ebay today, and maybe the single spark was a red herring!  compression reads 35 psi, 1200 psi less than it should.
looks like the heads coming off.

[andy230]

Hi Pete,

compression reads 35 psi, 1200 psi less than it should.

Are those numbers correct?   120 psi?

maybe the single spark was a red herring! 

Not being an arsenal,  but it still won't run without sparks every 720 degrees of rotation!

Was the throttle open for compression test? Have you put a bit of oil down the bore to see if its the rings?  Does it feel like there is reasonable compression with your finger over the plug hole and thumbing the starter?  Tho maybe not possible on the srx...

I have never had a non kickstart 600 yam, sorry not to be much use.  If you find a cdi on ebay, I have previously asked if I can return one if my problem wasn't the cdi. Legally I think you have 14 days to "change your mind" according to distance selling regs.

I did this for the dr, but ended up keeping the cdi. But I asked first and the guy said no problem.

Good luck, nice project!
A