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-   -   84 XT 600 won't start warm (https://www.horizonsunlimited.com/hubb/yamaha-tech/84-xt-600-wont-start-65544)

Mark U 30 Jul 2012 16:40

84 XT 600 won't start warm
 
Bike starts on the first kick when cold and runs excellent. Once it warms up (about 10 mins) it stalls and will not start, even after 100 kicks :(. Let it cool down and BAM, starts on the first kick.

Anyone have a similar issue with theirs?

Jens Eskildsen 30 Jul 2012 17:40

Can you start it cold without choke? It could be too rich on the idlejet and/or fuelscrew needed to be adjusted.

Hard starting when warm could also indicate you're up for a valve adjustement.

Mark U 30 Jul 2012 18:17

Thank you. It does start cold with no choke. I didn't think of the valves with only 7000 miles but will def look into that too.
Thanks for the advise.

Jens Eskildsen 30 Jul 2012 20:39

Try to adjust the fuelscrew first.

Its located hiddin in a slot, in front of the left carb. You need a small flathead screwdriver, or simular. Here's a picture of the location:

http://peecee.dk/uploads/072012/coscrew1.jpg


Before you play to much with settings: Turn it in and count the turns, so you can set it back to where it is if something should fail. Then try backin it out, but stop half a revolution/turn round before youre current setting, and see if it helps, if not, turn it in another half turn.

It should be around 1,5-2 turns out from lightly seated, but it varies from bike to bike.

Id still atleast inspect the valvelash, its fairly easy, and can give you peace of mind.

Good luck and keep us updated.

bacardi23 30 Jul 2012 21:25

Your sparkplug coil is starting to die!

Replace it and it should solve your problems.



Vando beer

BlackDogZulu 31 Jul 2012 03:51

Starting well without choke is a sure sign of a rich mixture. Dying when warm is another. Put it this way - I used the choke to start mine a few weeks ago and forgot to put it back. When it got warm, it ran rough at full throttle and wouldn't idle, and then wouldn't start again until I realised my mistake. That was a 'Doh!' moment. Get the idle mixture sorted out before anything else. Costs nothing to do this :)

If Jens' advice doesn't work, your next step should be to check the float height and the float needle. Float too high and/or a leaky float needle could give the same symptoms.

It might have a low mileage, but at 28 years old it's likely something has failed or gone out of adjustment.

Zergman 31 Jul 2012 07:06

It might also be a sparkplug: when a sparkplug heats up it might start sparking the wrong way (I don't know how to tell it in other way...).

By saying "the wrong way" I mean the spark jumps through ceramic isolation (where it might be cracked) not in the place it should be jumping.

Check the spark when the sparkplug is hot, it might be an easy fix.

Mark U 19 Sep 2012 15:26

84 XT 600 won't start warm
 
Thank you for all the input. I have changed the spark plug coil, adjusted the valves, changed the spark plug, cleaned the carb and played with the carb settings. Still doing the same thing. It appears someone Frankenstein'd the carb at some point. The Kiehien replacement is $450. I'm thinking a new carb will solve the problem. Any thoughts? Anyone have a solid, unmolested carb for sale?

2499 19 Sep 2012 19:55

I had the same problem with a car ones. It was the crankshaft sensor for the ignition. Maybe the same here.

You can pull out the spark plug after you kick it a couple time when it won't start. If it is wet, then you have fuel present. Then it must be a ignition related problem. Or it drowns because of to much fuel. But then the bike will drive like crape before it dies.

The carb is a relatively simple device. A general strip down will normally reveal any problems.

If you have installed a fuel filter , then you might get a vapor lock because of the heat from the engine. Tin foil around the filter will normally cure the problem.

Hope you solve the problem soon.


Christian

Bobmech 20 Sep 2012 00:09

The problem is obviously heat related.
I would first eliminate the ignition system by checking for spark when it's hot.
It may be something like a faulty ignition CDI unit. I had one of those play-up only when hot.
Bob

marcm 20 Sep 2012 07:48

If the valve clearances were fine,I would check the resistance of the stator/ pulse coil before starting to change a load of other stuff for fun of it..
Although if he bike has 7000 miles on it,one would hope it wouldn't be a problem?.
Good luck.

BCK_973 9 Oct 2012 04:38

Your Pick up coil is defect!I had the same.As they come with the alternator try to find someone who fixes them or getting a second hand alternator unit.
I fixed the unit and now starts every time even when ****ing hot!
Any update?


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