Hi All.

As per previous posts, my 43F (1984 kick start only) is starting and running better than it was after I cleaned the carbs and found a blocked pilot jet. However, it still takes many many kicks to start from cold. (10- 20).

It runs and ticks over fine once I can get it started, no pops on overrun, no hesitation on opening the throttle...

My mate and I ran a new earth line through the coil and the lights to the frame at the weekend. It still starts up like a lazy teenager, but the lights are bright and the brake light no longer flashes in tandem with the indicator.

So - ahead of working through the ignition circuit step by step at the weekend - I have a couple of questions I hope you can help with.

1. The only manual I have is for a 2004 TT600 - can I use the resistances specified there to check the pulse coil and ignition coil (primary and secondary)?
2. Can I assume the CDI is either good (the bike runs) or bad (no spark at all)?
3. Can I assume that the voltage for the CDI and the ignition coil are provided by the generator (magneto/alternator/stator) and that the state of the battery makes no difference to starting performance?
4. To check the secondary ignition coil circuit - do I meter the HT lead to earth?

Thanks in advance.

Jim

Hi
I am rebuilding my 85 55W now.In other tenere forum this was discused also by other and they said those CDI units where prone to fail.
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Have you checked the decompressor cable?Maybe its not acting sincronized?
You know exactly when you need to kick it?Need to wait for decompressor to click and then let the kick go up and give it full power!
Karl

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Try checking your valves. I had a similar problem, the exhaust valve was a little out of spec. After closing it a touch it now starts first time, every time.

Good luck.

Paul

Like Paul says, i'd start with the valve clearances. Rule out the simple stuff first. Easy enough to do, and something that needs to be checked from time to time anyway.

I'm no expert, but if it runs OK when it does start I reckon you can assume the CDI is working. They either work or they dont.

From my experience with badly starting XTs, please check / do the following first:
1. Adjust the idle mixture correctly. The standard factory setting will not work for your older bike. Warm up engine, screw out idle screw till engine speed increases, keep screwing out till engine speed starts decreasing again. Leave it there. You'll find that you'll need 4 maybe six turns out.
2. Adjust deco cable correctly (just to make kicking easier). With running engine, push level on cilinder head backwards, you'll feel the exhaust tappet at a certain point. The play in the cable should be approximately 1 mm, not more.

If the above does not work, try the other suggestions.

You cannot use the data from the TT600 2004 handbook - the ignition system is different. For correct data, check here, use translator if required: Wartungsdaten XT600-Modelle.
You can assume that the CDI is OK, in fact I have yet to see one go bad.
The electrical power for the ignition comes from the alternator, not from battery.

Good luck!

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Auke
http://aukemarieke.blogspot.com

Thanks everyone for your excellent suggestions.

As a result, the plan this weekend is now:

• Meter out the secondary coil resistance - I suspect the HT lead might be too old (high resistance) - 30,000 miles & 27 years. I have had cars that do this & new HT leads sorted the problem out completely It means a new coil for the XT - cheap off ebay if needed...
• Check the valve clearances (thanks for the link Auke)
• Set the pilot screw to 5 turns out (currently 2.75 turns)
• Start it - even if it takes 20 minutes (which it normally does from cold).
• Get it running and fine tune the pilot screw (PTFE tape on the thread will be required as it dropped out the last time it was screwed out that far).
• Check decompressor lever clearance (currently a good 5mm - I was paranoid about it being too small and burning the valve out).
• Keep you guys posted.

Thanks again

Jim

Try it like this:

1-Remove the the decompressor cable from the cylinder head decompressor valve!

2-With the bike on it's stand, put yourself on the bike

3-
a- Find TDC (top dead center: it's the highest point the piston sits on the cylinder).
b- In order to do this it might take a few tries but...SLOWLY apply some weight on the kickstart until it turns over the engine and locks!
c- After that apply some very light pressure on the kickstart until it moves just past that "lock" place and let the kickstart return to the normal position.
d- Full choke on!
e- Give it a few fast full throttle twists ( on mine 3 or 4 twist do the job) and let go of the throttle.
f- Make sure you have the ignition key ON ( done that before lol)
g- Remove the the clearance on the kickstart
h- NOW give it a FULL BIG POWERFULL KICK and the bike will start!

Might take a few times for you to get the hang of it but it does work!
That's how I do it on mine!


Vando

Thanks Vando for the routine of starting, this is how I do it. (Except I don't kick it past TDC, I feel like I get better momentum from kicking it from the lockup point).

Using this mine is still taking about 20 kicks to start. Up to now I have now done the following.
1. Set the valve clearences (I got a special set of cranked feeler gauges for this).
2. Set the pilot screw. Screwed out just to the point of reducing the tickover and reversed about 1/8 turn. This is about 3 turns out. I didn't use PTFE tape on the screw - apparently it turns to snot in petrol vapour. Loctite thread sealant did the job.
3. Metered out the coil and cap resistances. All in specification.
4. Left the decompressor cable at 5mm clearence. Until it starts right I would rather have too much clearence than too little.
5. Fitted an iridium spark plug. No diffrerence to starting but a huge improvement in idling stability - would recommend this £10 upgrade to anyone with a single cylinder CDI bike.

Jobs tomorrow...
1. Fit new coil (£18 incl post from Fleabay). Despite the good resistances, I still don't trust the old one
2. Fit new float needle kit and seal the float bowl (the o-ring around the float bowl seal is a bit rough).
3. Hope it starts properly now.

The only thing I have left is the suspicion of piston slap and reduced compression (although it still locks well at TDC on kicking it over).. If it is that, it goes on ebay. I haven't the energy or the money to get it rebored.

With the proceeds I will buy an XT600E and be done with a right leg that Popeye would be proud of...

As always, I will keep you posted.

Jim