ID a needle for me

[lornop]

Hey guys, got a used 2014 300ec a while ago. Just got the top end done on it and since then it hasnt been running as good. I dont have to use the choke to start it, and if I do, it revs really high until I shut shut off the choke. The idle screw doenst seem to do much and my bike wont idle more then about a minute without giving it a bit of throttle.

So I pulled the carb apart and I have a 38, 170 and the needle has no markings on it. It has a blue top on it though. Any ideas?

If i get one of the recommended needles (NEDW) will I need to put new jets in also? I ride from 0-300m and 15-30C.

Thanks for any advice, its my first 2 stroke so any help would be appreciated.

[gasgasman]

That would be a JD needle.

You may have a vacuum leak.

[lornop]

Does a vacuum leak mean a loose hose or the carb body needs some new gaskets/seals?

[gasgasman]

Yup.
Check reed block seals and the intake manifold for splits.

[memphis2857]

That's a JD blue needle. It is recommended by Richard Wilson. The main and the pilot seem really lean. Should be 40-42 and 175-178. Bump the pilot to a 40 and see how it acts and as stated above make sure the carb is seated in the boots. Good way to check is use some starting fluid and spray a little around any places that could be sucking air and listen to the engine. If it's sucking air the starting fluid will get sucked in and the engine will rev a little


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[lornop]

Awesome thanks for the help guys.

[webmaster]

Hi There -

Just one more note for you...

When a person is using a leaner pilot in these situations - they often have the idle screw turned all the way in to supply greater fuel from the needle/nozzle circuit of the carb. This is creating a scenario called "pulling over" - you are using two circuits in the carb at low rpms instead of one - e.g. you should only be using pilot circuit at idle - but now you are using pilot plus needle... When I first encountered this on a brand new 2001 ec300 with an n1ef needle - I said to a friend of mine - "what the heck is going on? The idle screw is cranked all the way in and it doesn't idle well. And the air screw doesn't seem to have much effect. And there is a surge as it transitions from low to mid on the carb and cleans up.". He said "It is pulling over..."

Given this - make sure that when you install the fatter pilot jet you reset the idle screw adjustment - turn it out a tad so it isn't "coil bound" any longer. This will drop the slide and make is so that the low end can be dialed in with the air screw much better. With this carb having an air screw setting greater than the "standard 1.5 turns out" is fine - I find that with a fatter pilot and a setting of 2.25 turns (for example) - you get back sensitivity of the air screw setting that was lacking when it is "pulling over".

jeff

[lornop]

Interesting, I was kind of wondering if there was something like that going on although my lack of experience I wasn't quite sure.

I went to the shop and a talk with the owner and the mechanic they gave me the 40 and the 180 jets and told me to try that. I have the air screw 1.5 turns out and it runs fine. I havent gotten it our for a full ride yet though, fingers crossed for some nice weather this weekend

Does the air screw only effect the idle jet or does it adjust the full range of throttle?

[memphis2857]

Only affects the pilot jet


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