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a bitch to start!

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ok. I 've got the low-end idle thing worked out on my new/used '02 XR400... but the bike is still a bitch to start when it's cold. Yeah, I find TDC or whatever it is... Yeah, I do six or eight kicks with the decompress lever... plug is fine. I've tried full, partial, minimal, and no throttle. And yes, the ignition switch is on. PITA!

It starts right up when its warm. (And BTW, I have an '85 XR400 that starts flawlessly every time, cold or not.)

Any suggestions?

Thanks, -d

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Sounds like a small jetting adjustment may be needed. Make sure your fuel screw in front of the carb is adjusted accordingly. I think the Gordon Mod write up explains it well.

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properly jet it, adjust the valves & install an iridium spark plug.

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Is your choke full on? Has it been modified? Try turning up your idle one turn (clockwise) kick through 10 times with decompressor on. Find TDC (the hard part of the compression stroke) without decompressor lever on. Use decompressor lever to go just past TDC. let kicker come all the way up and it should fire first time with a strong kick.

Next thing...pilot jetting is off.

BTW, your other bike is an 85 xr400? maybe a xr350??? if so, different beast.

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Thanks for the responses, folks. And forgive my ignorance with this stuff, but how would valve clearances affect starting?

nmhinton, yeah, it's an '85, and the pink slip says 400, it performs like a 400, but I guess it could be a 350, or maybe it was bored out.... why? Did Honda not make the 400 back in the day? -d

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Thanks for the responses, folks. And forgive my ignorance with this stuff, but how would valve clearances affect starting?

nmhinton, yeah, it's an '85, and the pink slip says 400, it performs like a 400, but I guess it could be a 350, or maybe it was bored out.... why? Did Honda not make the 400 back in the day? -d

I've heard that valves out of spec will make the bike really hard to start. It's probably valves, unless your carb is dirty.

Hey, once you get those valves adjusted, will you come show me how to do it? :applause:

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Thanks for the responses, folks. And forgive my ignorance with this stuff, but how would valve clearances affect starting?

nmhinton, yeah, it's an '85, and the pink slip says 400, it performs like a 400, but I guess it could be a 350, or maybe it was bored out.... why? Did Honda not make the 400 back in the day? -d

If they're tight it could be holding the valves open a little bit, making it hard to start. At least that's what I've read, and it makes sense, I haven't had that problem yet.

XR400's were first made in 1996, before that it was XR350's.

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milje wrote:

XR400's were first made in 1996, before that it was XR350's.

I did not know that! I guess I'm riding a bored-out 350. -d

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Hey this might be minor but it could work. My friend has a 1999 xr4 and i was trying to start it forever one day (out on a trail). I tried everything I could think of... clearing a flood, roll starting, checked the plug, etc etc. then he finally came back to find me and jiggled the kill switch it started right up. Might not be your situation but sometimes it can just be something simple.

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ok. I 've got the low-end idle thing worked out on my new/used '02 XR400... but the bike is still a bitch to start when it's cold. Yeah, I find TDC or whatever it is... Yeah, I do six or eight kicks with the decompress lever... plug is fine. I've tried full, partial, minimal, and no throttle. And yes, the ignition switch is on. PITA!

It starts right up when its warm. (And BTW, I have an '85 XR400 that starts flawlessly every time, cold or not.)

Any suggestions?

Thanks, -d

I don't see any mention of using the choke. It will never start without it when cold. It's also a 2 position choke, so if you only apply half choke it's still not enough for cold starting.

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Choke's on. I've messed with the kill switch, too. I've cleaned the carb, and replaced the slow jet which was completely clogged. I've installed a new plug. I have not checked the valve clearances, but I will when I get home... Babs- Ill let you know how it goes! -d

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Valves make a big difference. If they are opening not enough, loose specs, you are not getting the air you need and the exhaust is not being pushed completely out. If they are opening too much, tight specs, the exhaust stroke will open too soon and you will lose compression. And the intake valve will open to soon allowing exhaust to be pushed into your intake.

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I don't see any mention of using the choke. It will never start without it when cold. It's also a 2 position choke, so if you only apply half choke it's still not enough for cold starting.

I have to set my 2003 xr400r at full choke for cold starts AND warm. Even if I have been riding for an hour, I still have to use full choke to start it.

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Rob, yeah me too on the choke thing. Even when warm. That's why I'm intrigued by the discussion on the effects of proper/improper valve adjustment. My carb is clean as a whistle.

Gumby, thanks for the additional info... -d

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I have to set my 2003 xr400r at full choke for cold starts AND warm. Even if I have been riding for an hour, I still have to use full choke to start it.

That suggests your fuel screw and/or pilot jet circuit has a problem - maybe too lean/pilot jet too small? My 98 with a stock carb needs full choke for a cold start, but once it's warm, one kick on the compression stroke is all it takes. No choke required at all. The bike has Gordon mods, and is jetted 160/60, 2 turns on the fuel screw, I ride mostly at 100 - 400 feet above sea level and the jetting is just about perfect.

What's your pilot jet number? How many turns on the fuel screw? Bike run okay otherwise? Does it idle properly warm with no choke? No other mods? If you've done the Gordon mods, or otherwise modified the intake or exhaust, you'll need to rejet the stock carb.

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