hard starting o1 xr400

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Sep 16, 2001
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#1
looking for some help. I just bought a couple of xr's 400 and 100. The 100 can't wait to start, you just look at the kick start and it fires. I am not having as much luck with the 400. I've always heard that they were easy to start but it takes as many as 15 kicks , sometimes. The bike is easy to kick , thats not the problem, it just seems like a carb setting or timing might be off. Anyone have a quick check list of things that might be a little off? I've got a 99 yz 400 that is way more consistant than the xr. Float level, air screw? The bike is three months old, clean filter, plug looks alright, bike runs fine after I run it for a few minutes. Anyone?
 
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Sep 22, 2000
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#2
When cold starting I turn up the idle a couple of turns. Once its warmed up it starts easy, like yours. It usually only takes me a two to three kicks to get it fired up.
 
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May 17, 2001
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#3
When I bought my 98xr400 (used) I took it out, and it took about 50 kicks before I got it started. I turned the idle up only about 1/4-1/2 turn, and it started first kick. Try turning your idle up.

Jeremy
 
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#4
Hey,
The newer XR's are jetted leaner than the 96-97's. If you remove the snorkel or the baffle in the pipe you will need to rejet. If you are pure stock, you jetting should be in the ballpark, but tweaking might help.

Try this when starting it cold. Turn on gas and full choke, lay the bike over on it's side for a few seconds, don't lay it on the ground, just tip it way over. Jump on the bike, and kick all the way through. She should fire off within 2 kicks or so. My bike hates to start when cold, but when she's warm/hot she starts first or second kick every time. The lay over trick works great for me to get fuel to the cylinder quick.

Finally, adjusting the idle up when cold does help too. Leave it idling high until she warms up, just make sure to idle it back down within a few minutes.
Good luck, keep on thumpin'!
 
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Sep 16, 2001
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#5
starting is easy

Try this..
Turn on the fuel, if starting a cold engine then use the choke,
DO NOT touch the throttle at all, stand by the side of the bike (on the kick start side) find TDC by slowly moveing the starter untill you find a possitive resistance. Release the starter lever back to its rest, finally stand on the starter with all you got. (remember do not touch the gas as it will flood)

If you need to start a hot engine, say after a stall or you have just come off, first clear the chamber by switching off the fuel, hold in the de-compression lever and rapidly work the kick starter for about 6-8 times and then repeat the above procedure.:D
 
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#6
I hated my xr400 til' I learned the idle screw way to the right trick. So now:

1) Fuel on, Choke full

2) Idle screw one full turn to the right.

3) Pull decomp. lever. Kick several times. (Only time you can give any throttle at all, if you like). Release lever.

4) Find tdc. Pull decomp. lever. Push kick starter 1/2 inch down.

5) Let kick starter up a little, then give long, thorough, kick.

6) Bike starts, immediately go to half choke. When warm, off with the choke. Remember to slow idle.
 
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#7
I just picked up a '97 XR400 but I don't have the manual yet. Is the idle the larger diameter black, serrated knob or the smaller brass-looking deal with the screw slot on the end?
 
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#8
idle knob

The Idle knob is the big knurled one, the other adjusts the mixture or volume. But if the choke is set up correctly then you have no need to touch any of them.

If you have mooved the small brass mixture screw for any reason, the rule of thumb setting is between 1.25 and 1.5 full turns out from the fully wound in possition.( take great care not to wind it in too hard to start as it will damage the brass seat it rests on )
 
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#9
Basic thumper starting procedure - for ALL four strokes. This is from many different sources - and as a short person, I can attest to its ability to work on everything from an XR250 to a YZF 426.

Cold starts:

1. Choke on
2. Fuel on
3. Bike in neutral, do not pull in the clutch
4. Pull in the decompressor lever and crack throttle wide open. Do not let off on the throttle - hold it completely wide open (this raises the slide and allows air into the head).
5. With the decompression lever and throttle held on - kick the bike 10 times. Just like you're priming a pump (that's what you're doing).
6. Let go of the decompressor lever - let go of the throttle.
7. Take your throttle hand OFF the throttle - grab the crossbar (you may not think you'll gas it, but everyone does, we just don't realize it!).
8. Slowly kick the bike through and feel for the point where the kicker wants to stop (like you'd have to apply some muscle to continue to kick it through). there are a few points that feel like this, the hardest point is Top Dead Center (this is the one you want!). Stop there.
9. Pull in the decompression lever, this will allow you to gently rotate the piston just past top. You will just move your foot on the kicker maybe 1inch or slightly more. If it's quiet, you can hear a little "thup". The piston is now just past the top of the stroke and is ready to be kicked.
11. Let loose of the decomp lever. Allow the kicker to come back to the top of the stroke.
10. Kick the bike.

An efficient four stroke kick requires smooth, consistent action - it doesn't necissarily have to be fast or hard, just smooth. Make sure you use a complete kick - all the way through from the very top of the stroke to the very bottom.

The bike should start. If it doesn't, just follow the procedure from #8 onwards. Don't give it any throttle until it fires off.

HOT STARTS
Use the same technique as above (without the choke) if you crash the bike or if it's gotten very hot and doesn't want to start.

REGULAR STARTS (after warmup)

Use the procedure from #8 onwards. ALWAYS use the decompressor to get the piston just past top dead center whenever you start the bike. It's faster and easier on the bike (and the rider :)

If it's really cold out, or if you haven't started the bike in awhile (weeks) - use the "lay the bike over" technique mentioned above. Lay the bike on its side until fuel flows out the overflow tubes (coming out of the carb). This will give the carb a nice full charge of fresh fuel.

I am 5'4". I'm a wimp. I've used this technique to start everything from XR200's to bored and stroked YZF 426's. It really does work.

BTW, every bike has it's own "best" starting procedure - at some point, you will find that your XR4 may want a tiny bit of throttle just as you're kicking it and it starts easier. Some do, some don't. Experiment with it :)

Happy Trails!
 

fremontguy

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#10
Turning the idle up and choke full on to partially cracked open at TDC will help on cold starts. The hot starts(after tipping over) are best done by holding throttle wide open when kicking, and then let off slightly when it starts and rev the heck out of it. I finally mastered that last techniqe and it starts after 2nd kick:cool:
 
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Feb 12, 2001
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#11
My new xr4 was also hard to start when cold. After unplugging the air box, fitting a PC T-4 pipe and grinding out the welds in the head pipe, I jetted the bike according to" SRC Jetting Recommendations" that I got from my dealer.

98-00 XR 400

STD low med open
52pilot 55 58 62
142 152 155 162
needle
2nd from 2nd 2nd 3rd
top

'low' is is stock exhaust or after market with low volume baffle(quiet)
'med' is stock exhaust that has been slightly modified(different tip) or after market with a medium volume baffle or average amount of discs installed
'open' stock exhaust with no baffle, after market with maximum amount of discs or open volume baffle(loud)

I used these as a starting point, then corrected for elevation according to the charts in the service manual. The bike now starts in 2-4 kicks cold, and usually 1 when hot. Cold- full choke, no throttle(if not in 3 kicks, I go to half choke and it fires right up). I never touch the throttle when starting it now, but stock it did seem to like it cracked open a little. Also, I always start to kick with the piston at TDC. XR4's have an automatic decompressor geared into the kick starter, so there is no need to use the decompression lever. Just push down untill it gets hard, return to the top, and kick all the way through.
:)
 
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#12
Sorry, my attempt at the chart above didn't come out to good:confused:

STD - 52pilot , 142main , needle 2nd from top

low - 55 pilot , 152main , needle 2nd from top

med - 58 pilot , 155main , needle 2nd from top

open - 62pilot , 162main , needle 3rd from top