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HELP XR400R 1997

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Hey everyone new to forum , I was wondering if anyone has seen these issues with my dirtbike first off I'll start with my Honda xr400r (1997) , so first off the bikes would ride fine but have been stored for more than a few months,  to start my Honda I have to open the choke all the way or it won't start once I get it on after 2-4 kicks with the choke open she starts up and once I turn off the choke it idles ok sometimes it'll sound low idle but will than stay idling and when I lightly pump the throttle it sounds fine but once I open past half way it sounds kind of boggy and if I hold it open it'll just completely just bogg down and die and I've tried filling the tank complete of gas and it's still the same issue could it be the carbs ? Would cleaning the floats be enough or would I have to clean the jets aswell ? And how would I adjust them back how they should be ? What could be causing it to die like that because I can ride it fine if I don't use too much throttle but if I try and open it a little too much it's starts to bogg or will just bogg down and die ...?? Any help please I want to open carbs and clean them but unsure if I remove jets that I will not tune them back how they should be if they need tuning??

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Take carb apart and clean jets for sure. Use carb/choke cleaner from your local Auto parts shop. Compressed air to blow out holes. Jets are just pieces of brass so as far as messing up settings you really can't mess it up. Setting the float height may be the only problem you encounter. This site has great forums already designated to carbs/jets/jetting. Check those out as well.

And what may  be causing it to get boggy could be too large main jet. Whats the spark plug look like?

Also, ALWAYS have owners manual nearby.

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2 minutes ago, 506 yz125 said:

Take carb apart and clean jets for sure. Use carb/choke cleaner from your local Auto parts shop. Compressed air to blow out holes. Jets are just pieces of brass so as far as messing up settings you really can't mess it up. Setting the float height may be the only problem you encounter. This site has great forums already designated to carbs/jets/jetting. Check those out as well.

And what may  be causing it to get boggy could be too large main jet. Whats the spark plug look like?

Also, ALWAYS have owners manual nearby.

Hey thanks for quick reply , so for the jets if I remove them and get new ones or clean them I would just screw them back in completely? No adjusting? As for the float I thought that was the one that wouldn't need adjusting thanks for the heads up! ? how wouI'd I find these threads on carbs/jets /jetting?

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Your problem is most often caused by a dirty/plugged up fuel screw passage. The fuel screw tunes the pilot jet system.

The jets themselves are not adjustable, just clean them and screw them all the way back in.

This video should help with working on your carb.

 

Edited by Trailryder42
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also, read this article. I understand it is for a Yamaha 2 stroke but carbs (as confusing as they are) are all basically the same.

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11 minutes ago, ThumperCurtis said:

^^^^^^^^^^^^ This 

 

It sounds like you have a carb passage blocked. Clean it well and try again. 

If I don't have compressed air can i just wait until it's completely dry ?

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3 minutes ago, Carlos Galindo said:

If I don't have compressed air can i just wait until it's completely dry ?

If you don't have compressed air, take it to a friend with a compressor or friendly garage and have them shoot air through the passages. Last resort - buy some air in a can (like a air duster) or brakeleen and use that. The whole point is to blow out any gunk in the passage. If you let it dry it stays in the passage and does nothing.  

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Just now, ThumperCurtis said:

If you don't have compressed air, take it to a friend with a compressor or friendly garage and have them shoot air through the passages. Last resort - buy some air in a can (like a air duster) or brakeleen and use that. The whole point is to blow out any gunk in the passage. If you let it dry it stays in the passage and does nothing.  

So I can go to Wal-Mart and get like a dust-off can and that'll work? , also quick question I havnt had this bike for very long but to use the choke which way is the choke open and which way is closed when I have it down all the way it sounds like a high idle and when I have it up it's a slow steady idle and the middle one sounds the same as if I had it down all the way ?

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If you don't have compressed air, take it to a friend with a compressor or friendly garage and have them shoot air through the passages. Last resort - buy some air in a can (like a air duster) or brakeleen and use that. The whole point is to blow out any gunk in the passage. If you let it dry it stays in the passage and does nothing.  

Or you may be able to unplug with a needle or small piece of wire... I would think the culprit will end up being tarnish in the the carb bowl. But (and I'm not 100% on this), couldn't it also be an altitude (clip height postion, as well as improper jetting for elevation)?

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1 minute ago, Carlos Galindo said:

So I can go to Wal-Mart and get like a dust-off can and that'll work? , also quick question I havnt had this bike for very long but to use the choke which way is the choke open and which way is closed when I have it down all the way it sounds like a high idle and when I have it up it's a slow steady idle and the middle one sounds the same as if I had it down all the way ?

Yes a dust off can will work. 

 

As for the choke when the lever is in the "UP" position you are engaging the choke and restricting airflow to richen up the air fuel mixture. When it is "DOWN" then the choke is disengaged. In the DOWN position you can use the idle screw to adjust the idle down. It is the one with the ridged black plastic knob (see picture). In this picture the choke is DOWN (disengaged). 

02xr400carb.JPG

 

 

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Just now, Brolobowlin said:


Or you may be able to unplug with a needle or small piece of wire... I would think the culprit will end up being tarnish in the the carb bowl. But (and I'm not 100% on this), couldn't it also be an altitude (clip height postion, as well as improper jetting for elevation)?

I would not use any sort of wire in the carb as it could cause more harm than good - especially in brass jets or inserts.

 

As for the clip position you are correct it could be an altitude issue however he didn't mention that he or the bike has had a change in altitude. Good point. Check that the jet needle is on the middle clip.   

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29 minutes ago, ThumperCurtis said:

Yes a dust off can will work. 

 

As for the choke when the lever is in the "UP" position you are engaging the choke and restricting airflow to richen up the air fuel mixture. When it is "DOWN" then the choke is disengaged. In the DOWN position you can use the idle screw to adjust the idle down. It is the one with the ridged black plastic knob (see picture). In this picture the choke is DOWN (disengaged). 

02xr400carb.JPG

 

 

So than everything I start the bike I have the choke off? Because it would only start middle position or down position or atleast I tried my hardest to get it on in those positions .. so I definitely want to turn the knob way down to adjust that high idle?

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Whenever I have the gas open at the tap there's these two overflow hoses I believe they are from the bottom of the carb that they just dump out gas whenever the bike is off but not when the bike is on ..?

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When I startup I put the choke to 1/2 (there is a little detent that goes to 1/2 way), kick over 3-4 times with the decompression lever in, find TDC and then with one sturdy kick - WHOOOM. After 10 sec I flip the choke to the down position (off).  

 

If the idle is high then adjust the knob

Edited by ThumperCurtis

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3 minutes ago, Carlos Galindo said:

Whenever I have the gas open at the tap there's these two overflow hoses I believe they are from the bottom of the carb that they just dump out gas whenever the bike is off but not when the bike is on ..?

Carlos - that typically happens with the float high is too high and the excess fuel dumps out the overflow. Pull the carb and give it the once over (clean and adjust). 

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4 minutes ago, ThumperCurtis said:

When I startup I put the choke to 1/2 (there is a little detent that goes to 1/2 way), kick over 3-4 times with the decompression lever in, find TDC and then with one sturdy kick - WHOOOM. After 10 sec I flip the choke to the down position (off).  

 

If the idle is high then adjust the knob

Yes I have bike on right now but I have choke in up position and it sounds like a steady idle but as soon as I go down half or all the way down it idles very high I've been trying to take videos but won't let me post them

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