E-start setup

Oooops....

Hey Coastie,

Trust me, it is neither the decomp nor the valves.

Ala your first post and tuts's offer to send an updated decomp arm, I did update that with the latest factory incarnation.

As for the valves and timing, I know how to set up these engines to work the way they should.

As I said the valve lash was taken out of the equation initially and then added without concerning additional resistance.

To separate the issues, tight valves are an issue when it comes to starting and then they effect both e- and kick-start. Tight valves will not prevent the autodecomp mechanism from doing its job, in actually fact tight valves will help the mechanism to do its job.

Loose valves will of course cause an issue with the autodecomp mechanism preventing it from opening the exhaust valves properly.

The other decomp devices don't come into it. They are separate systems. Unless you use a feeler guage and don't account for additional pressure that there might be from the return spring - where it might cause a problem.

Valve timing I also know is correct. I have tested many different cam shafts on this engines and this one is timed to within necessary tolerances.

Remember for me the issue was not starting per se, but cranking speed from the battery alone (now, I suspect this may have been a red herring but more of that shortly).

Loose valves do not cause the same amount of problems with engine starting than tight valves (unless they are really really loose of course), but they will cause added difficulty (this is particularly on the e-start), but again, not the issue because I do not have a problem with too much compression on the compression stroke and because the valve lash was added from zero gradually.

What I have found regarding cranking speed is:

1. It may not have been the underlying problem, just a symptom;

2. I had added an ignition switch which was incorporated into the ignition circuit. I removed it from the equation;

3. I cleaned up and double checked the solenoid;

4. Now, providing my battery (YTZ7S) is showing more than 12.8V it will start the engine, hot or cold;

5. If it falls below this level, it seems cranking voltage falls below that required to fire up and therefore it doesn't start;

6. At this point if I use a booster starter or an additional battery, the engine will fire immediately without any improvement in cranking speed. It just adds to cranking voltage and therefore indicates my search for more cranking speed was somewhat misguided;

7. I believe that the ignition switch was causing a problem somewhere in the signal from stator to ignition box. I'm going to add it back into the circuit now to see what happens;

8. I believe that previously,if there had been a problem with the ignition switch, added rpms were required to get it to fire up. Perhaps this is a resistance issue, I don't know. Perhaps Bundybear might be able to clarify this?

9. The cleaning up and reconnecting of the solenoid may have made some difference;

10. The Yuasa manual states that above 12.4V the battery is fine and does not need charging. However, as above for me it seems it needs to be 12.8V or above. Otherwise the cranking voltage just drops too much (to below 10V instead of 10.9-11.2V which seems to be that required to fire the engine up;

11. Bundybear, if you're still reading this thread, could you explain whether this might point to a fault in the battery? Or maybe my multimeter :wink:

12. Does anyone know for definite what the purpose of the white wire into the coil is for? Clearly it requires 12 volts. What is its relationship to spark generation?

I think we're finally getting somewhere with this.....

All the best,
Simon

Hi Simon,

I see you considering resistance issues - if this helps...

I cut a factory KTM SMC ignition switch, (mounted beside the speedo) into my 06 by intercepting the stator pickup (green) and ran new 16ga wiring upto the switch and back. I cut into the pickup wiring above the carb, so I probably added 3ft of wire to this circuit. I also intercepted the 12v prime power at just outside the fuse block and ran it up the switch and back for an additional wiring length of 6ft.

These changes (additional wiring lengths) had no noticeable effect on e starting, in my case. Everything else is stock.

Cheers and I look forward to hearing the final chapter on this one - soon....

Mark

Simon
Do i have this correct.
Initially - off battery alone - not enough speed to start it.
A booster/charger across the terminals - spins it faster and starts it.
Now - A booster/charger across the terminals or straight onto the starter make no difference because it's now spinning faster.
So.... it works then ?
I presume not.
My reasoning for valves/autodecmp or anything other than electrical being your problem is simple:-
By taking the plug out there is no drag on the motor - so its free to spin at any speeds.
These motors although rated at 12v are happy enough with 24v for a short period - I know ! And will spin nearly twice as fast.
Therefore with no drag, pushing the button releases for example 200 RPM, you press this for 10 seconds and it remains constant. So, if you then add a charger/booster (which can initially rise upto @ 18v) it spins faster, say 250 RPM. However this will only be for a short period as there will be little current.
The reason a normal battery added in parallel is making little difference is because you have not increased the voltage just the current - it's still 12v
Presently, you are getting little difference between adding a 12v battery supply to either point, even with the plug in ! So, as long as there is no detioration in the revvs if you press it for say 10 seconds, it proves their is whatever is being delivered form the battery to the starter motor with no major loss.
Either your starter motor is not designed to spin fast enough or has worn out. Or and more likely, you have too much mechanical drag - usually in the shape of autodecomp or valves.
It may be something else, but, that is why i don't think it's electrical.
BTW. Little things like earthing, cable sizes, cleanliness etc all help but arent usually the main source of the problem.
Let's get this one nailed, for the record.
Stick with it mate and let us know
Regards
Ady

chilledspode,

Thank you for your clarification, that is very helpful.

Ady,

Yes it is working - absolutely brilliantly.

The conclusion I came to was that chasing the cranking revs beyond what I already had from the battery was not the solution. It doesn't need the extra speed I thought was needed (i.e. with the booster attached).

It still spins over pretty much at the same rate it did before on battery alone and starts mostly within about 5 revolutions cold and one or two revolutions after running for only a few seconds previously.

BTW this change happened without any modification to any mechanical items on the bike, only electrical as per my list above.

Now, even though it is working I want to know why it didn't, that's why I'm continuing to look for answers.....

All the best,
Simon

LeFrog said:

Where are you? What year bike do you have?

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San Diego 2002 650 fe

Hvywt said:

LeFrog said:

Where are you? What year bike do you have?

Click to expand...

San Diego 2002 650 fe

Click to expand...

And what did they do to the bike to try and make it start on the button? Do you have a bill or invoice showing the work?

Maybe they part of the job, but $1000 is a bit expensive, unless they replaced other things.

I myself will finish my rebuild this weekend (it's really hot in my garage, I can stay more than 1 hour at a time without losing 2 or 3 pounds) and I will be able to say if the auto decomp upgrade is part of the solution, but an upgraded starter clutch as well as a beefy starter motor (yours should be fine unless it's worn out) may help. Also of course timing and valve adjustment needs to be spot on (repeated a billionth times). You might want to look into a dual battery setup.

If it starts on the kick, you might want to stick to that otherwise. I have seen people start their 650s in 3 kicks.

Simon
I'm glad your working again.
Perhaps, as this thread has run its length, you would conclude in one last post. The symptoms, What you did and what was learnt, in order for others to also learn.
Regards
Ady

Ady said:

Simon
I'm glad your working again.
Perhaps, as this thread has run its length, you would conclude in one last post. The symptoms, What you did and what was learnt, in order for others to also learn.
Regards
Ady

Click to expand...

I will certainly do that.

Thanks for all your help.

Be well,
Simon

Congrats Simon

Sounds like it's starting as it should and it also sounds like your on top of valve/decomp setup.
Sorry if my last post seemed a little condescending but it's often the simple things in life that are overlooked.
I too had some strange electrical gremlin that would make it stop when it got wet....sometimes.
I could never simulate it by hosing etc and 1 day just got out there and pulled apart every connector, cleaned them all up, applied the vaso and waterproofed them all with silicon in the ends and tape over the top.
Also run a nice new ground cable from the battery to the cluster under the tank.
Fixed the problem. To this day I don't know what actually fixed the problem. I suspect the grounding.
If you find an absolute cause the please let us know.
Coops

I suggest we have a sticky with links to all the different threads about the recurring questions.

I see that on other sites. It seems to work well.

I just think the shop is unable to do the job right. Tha is why I am looking for a good shop. I was at the KTM shop today to see about trade in

Hvywt said:

I just think the shop is unable to do the job right. Tha is why I am looking for a good shop. I was at the KTM shop today to see about trade in

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Well, you just arrived among us and now you're leaving?

Too bad you did not come here for advice before seeing a mechanic.

Well, last night I found a rather significant and variable resistance in my circuitry.

Using an old ignition ket switch from a road bike I had lying around in the garage meant that literally everything was going through that (apart from fat battery cable this is). It clearly had a couple of bad wires...... even though when I put it together no resistance was showing on test, oh well, so much for the positive recycling mentality :wink:

At least I now know where I stand :roll:

All the best guys, I've learnt a lot with this stuff and plan a checklist for others to follow.
Simon

pleas do simon. what did the ignition switch change then? all was good?

regards

Taffy