Main Vs. Needle Jet (emulsion tube

[Guest]

Hi everyone. I am a newbie here, and yes, I am foolishly going to put pods on my 83 450 LD. <br><br>I know enough about jetting my Mx bikes but have a question I could not find the answer to here (I'll be searching forever)<br><br>My question is this. When I put pods on, yes I know to get richer main jets, but, do I need to get a large needle jet aka emulsion tube? Or is just the main jet what I am after right now.<br><br>I'll mess around with the pilot and jet needle as required. <br><br>Thanks guys.

[JEEPRUSTY]

You may be able to get differenct needles but I doubt that there ar alternate emulsion tubes for the 450 there are none for the 83-86 550

[Steve]

Look at it this way:
Q: Why are different jets "necessary" when installing pods?
A: Because of the increase in airflow.

Q: What causes the increase in airflow?
A: Removal of the (somewhat restrictive) airbox.

Q: When is the airbox "restrictive"?
A: Pretty much only at full-throttle, high-RPM.

Q: When the bike is running such that the needle jet is the main metering device, is the airbox the main airflow restriction?
A: No, the needle jet is mainly in use during mid-throttle operation, where the throttle is the restriction.

Q: Are larger needle jets (and/or pilot jets) necessary when installing pods?
A: No.

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[Agemax]

Q: Are larger needle jets (and/or pilot jets) necessary when installing pods?
A: No.

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Occasionally larger pilot jets ARE required when installing pods.

[JEEPRUSTY]

hmm yeah saying no does not admit that the flow increases in an analog fashion.
Its not as if the changes are like switches 1 2 and 3. The flow is a combination of all three over the throttle range.


But you are stills crewed I doubt alternate emulsion tubes exist.

A good cleaning of them little wee holes in the tubes may surprise you more than a change anyway.

[Steve]

Occasionally larger pilot jets ARE required when installing pods.

There may be that rare exception, but as I pointed out in the Q&A session, at anything less than full-throttle, high RPM operation, your throttle (butterfly or slide) is going to limit the airflow. I don't see how, if the throttle is the limiting factor (not the airbox) why any more air would flow, which is what would require larger pilot jets. Yeah, go to a big-bore kit or change the cams, you are changing jetting requirements, but in my mind, simply removing the airbox-imposed restriction shouldn't change the pilot jetting.

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[Agemax]

but in my mind, simply removing the airbox-imposed restriction shouldn't change the pilot jetting.

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that exception is not all that "rare". Also why do Dynojet supply their famous needles with "thinner" and reprofiled tapers? Answer....to allow more fuel flow at low to mid range when fitted in conjunction with pod filters.

[Steve]

that exception is not all that "rare". Also why do Dynojet supply their famous needles with "thinner" and reprofiled tapers? Answer....to allow more fuel flow at low to mid range when fitted in conjunction with pod filters.

Yet they don't provide new pilot jets.

Funny how that all works.

Not sure if I will get to ironing out my jetting before the snow flies here, as I have a MAJOR oil leakage problem with the bike that needs to be addressed before the 'fun' stuff happens, but I am always thankful that I have chosen to stay with the stock airbox. Ignoring the jettingn problems for a moment, I'm not sure I could live with the extra noise of the pods. I am also not looking for that last tenth of a horsepower out of the engine, and definitely NOT going for a "minimalistic" look, so I'll stick with my stock airbox and clean the K&N filter insert every once in a while.

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[Agemax]

Yet they don't provide new pilot jets.




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They do with some kits, although not any GS's as far as i know!