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Jetting Question XR400

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I've got a 2001 XR400, Stock carb, Gordon mods, sea level riding.

 

Reguardless of what Jets I currently have, whats the fix for these Jetting symptoms?

 

 

1.  Hard to start cold (MAIN PROBLEM WITH BIKE)

2.  Easy to start when warmed up

3.  Runs good in all throttle positions (Not lean or to rich, just right)

 

     Bumping up the idle helps the cold starting but the idle is off the chain once it warms up.  Is there a jetting change that will help this so I don't have to constantly change the idle or open the throttle partially when starting?

 

     Current starting procedure is 9 slow kicks with throttle wide open, the DTC, hand off throttle, one good kick.  It normally fires off but soon dies.  That's when the starting nightmare begins.

 

     Any ideas?  Or buy a pumper carb?

 

    

 

 

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  Raising the idle is the normal procedure on that bike.

You can also try increasing the power jet size by one size (the jet that works with the choke circuit)

 

 

Normal starting procedure stone cold on that bike is:

 

Ignition off, throttle wide open, 10 kicks

Ignition on, throttle closed, choke on, 3-4 easy kicks, then one hard one from TDC.

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Had same issue with an XR400.  I put a pumper carb and turned it into a 1-2 kick bike even cold.  Expensive fix though. I had went with the Edlebrock. 

 

Seems all of these bikes have different preferred starting procedures.  I used something similar to what Kranny described with exception to the ignition (had the R model) and used 2 easy kicks was with the compression release lever pulled in...  until I bought the pumper.  Then went with an even more expensive fix and sold it to buy the CRF450X  :)

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I have had three xr4's and all work and start easily hot or cold with this jetting. 60 or 62 pilot, 158 or 160 main. Needle always in middle(stock) position. Usually three kicks cold and one when hot. I never touch the throttle when cold but use full choke. I use these settings from sea level to 10,000ft.  Have no idea what ignition (on-off) or power jet Krannie is talking about.

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Ignition off, throttle wide open, 10 kicks

Ignition on, throttle closed, choke on, 3-4 easy kicks, then one hard one from TDC.

 

Ignition.  What is this "Ignition" you speak off, LOL

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Starting using the normal XR4 procedure is still hit and miss if its cold.  I am normally required to give it 1/4 throttle to get it going.  Is there a jetting fit that will eliminate the need for adding 1/4 throttle?  Larger Pilot?

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Starting using the normal XR4 procedure is still hit and miss if its cold.  I am normally required to give it 1/4 throttle to get it going.  Is there a jetting fit that will eliminate the need for adding 1/4 throttle?  Larger Pilot?

No, larger 'power jet' (choke circuit)

..or smaller, I don't know what your issue is exactly. 

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I'm assuming by "ignition" off he means hold down the killswitch while kicking.  Old XR trick, however it seems to me might either need a valve adjustment or have an intake air leak.  I'd start there

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I'm assuming by "ignition" off he means hold down the killswitch while kicking.  Old XR trick, however it seems to me might either need a valve adjustment or have an intake air leak.  I'd start there

Edited by Krannie

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