MK2 running on problem

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madmanreevo
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MK2 running on problem

Post by madmanreevo » 30 Aug 2009, 18:57

Me and the brother inlaw both have the same problem with our mk2's. They both run on when shutting the throttle, the revs settle down to normal tickover after a minute or thereabouts.
Sorry if its been covered before but i have searched and only found info relating to the AR
Many thanks.

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josh mk 2 crm
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Re: MK2 running on problem

Post by josh mk 2 crm » 30 Aug 2009, 21:30

haha me too!

ive heard a few people mention this problem but as yet i havent found the answer!

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Re: MK2 running on problem

Post by Eddie Evans » 31 Aug 2009, 09:59

If this is what I think it is most 2 strokes do this at times.
Mine seems to do it when it is getting hot but I have also heard new KTMs doing the same in similar conditions and have stopped worrying about it.

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Re: MK2 running on problem

Post by fallenmikethebike » 31 Aug 2009, 11:04

:) I'm with Eddie, you could twiddle with the mixture screw, for the current climatic conditions, but, in six weeks it will require twiddling again, if it bothers you that much.
Mine also shows the same trait on occasions, but i tend to ignore it, if it got any worse i might investigate.
Possibly, because it's a Trail bike ,and not a competition bike, it's jetted a bit leaner, to give better MPG, and emission figures.
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knackeredMk1
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Re: MK2 running on problem

Post by knackeredMk1 » 07 Sep 2009, 10:28

Most likely that the throttle cable is sticking a bit. Could only be a slight kink in the cable or a little bit of fraying.

Otherwise it can be slightly lean. - Try richening the air screw or going up 1 size on the pilot jet. If it is jetting it's going to get worse as the weather gets colder.

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madmanreevo
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Re: MK2 running on problem

Post by madmanreevo » 07 Sep 2009, 15:44

Hi its not the cable as these have been off and oiled...I have altered the mixture screw turning it out, from past carb tuning experience i recall you should find the point the bike idles highest so ideally midway....however mine is at the end so I believe it needs a bigger jet....anyone any experience on the crm's as a good jet size to try?

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Re: MK2 running on problem

Post by knackeredMk1 » 07 Sep 2009, 18:08

If the bike is running lean then you need to screw the the air screw in to richen it.

If you want to change the jet go up go up 2-3 digits from the one you are using. (The number will be stamped on the side of the jet).

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Jonorow
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Re: MK2 running on problem

Post by Jonorow » 07 Sep 2009, 21:38

if you screw the air screw fully in and the engine does not die you will need a bigger jet.
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reeves
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Re: MK2 running on problem

Post by reeves » 19 Sep 2009, 15:28

my bike has a similar problem it runs for a minute on tickover then dies !

i raised the tickover and it was fine for a while but has since cut out and now cannot start it !

can anyone help
i had a look at the coil and had to cut it down to get a good connection again and the plug was black !

if anyone can help ill be most greatful

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Re: MK2 running on problem

Post by knackeredMk1 » 19 Sep 2009, 18:32

Not many bikes of this age will run at tickover for a minute. They would have done when new but not now.

There could be a whole host of reasons why it stopped but my suspicion is that there was too much fuel/oil mixture in the cylinder and it just was starved of oxygen. - particularly if you used choke to get her started. The blackened plug supports this.

Lazy way - Take the plug out and leave for a few days. Turn the engine over with no plug in and no throttle a few times before putting the plug back. Should be able to start now.

Once you have got the engine started try to get the choke off as soon as possible. Blip the throttle but don't rev the engine. When you feel it can run comfortably without choke ride it but gently. After about 30s/1m allow the engine to rev out in a low gear. You will notice it needs to 'clear its throat' and will rev much better after doing this.

In the end it's all about feel, experience and mechanical sympathy.


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