2005 400ex breaking up!

[alpha6164]

I have two 2005 400ex and back in Oct i pretty much tore both of them down. I adjusted the valves, changed oil, filter, cleaned the carbs, removed the choke, put a larger, 42 pilot jets, and put new spark plugs. They both ran great and crisp and ran them for a couple of hours each in some trails.

They both have sit for about two months without starting. Now when i did all this it was 80deg and not it is 50deg in florida. Yesterday i went to start both of them up and it took a while for both to start. One of them eventually stared and after it warmed up, it sounded very crisp with no issues.

The 2nd one took twice as long to start and maintain an idle but even after idling for 3-4 minutes when i hit the throttle i hear cracks and pops and does not rev smoothly. Is there something i need to adjust? All inputs appreciated.

[rocky_mtn_honda]

try some fresh gas, and im sure another carb cleaning is in order, at least the pilot circuit...gas is only really good for about a month or so

[alpha6164]

Originally posted by rocky_mtn_honda
try some fresh gas, and im sure another carb cleaning is in order, at least the pilot circuit...gas is only really good for about a month or so



I thought about that but the fact that both of them have been garaged and one runs perfect and the other ones dont is what threw me off. And since the last carb cleaning they were run no more than 2hrs each. I didnt think that the carb would get dirty so quickly.


Honestly, my first thought was that due to temperature change that I am running lean due to denser colder air, just not sure how to richen the mixture up.

[rocky_mtn_honda]

drop the needle a clip position, or adjust via your air mixture screw...you shouldnt have to run a fatter main in the colder months

[alpha6164]

Originally posted by rocky_mtn_honda
drop the needle a clip position, or adjust via your air mixture screw...you shouldnt have to run a fatter main in the colder months


Sorry if sound like an idiot, but what do you mean "drop the needle a clip position" Any pics or diagrams on where this air mixture screw is located? I remember reading somewhere that i would need a D- shaped tool to adjust this? Or was i reading the wrong thing. Thanks for the input.

[rocky_mtn_honda]

a good blown up 2005-2009 carb image...the clip you should move is on the jet needle, you raise it by dropping the clip down one slot, and this in turn lets more fuel in. do you have the manual for your bike? reason i ask is because im not too sure about the d wrench for the air screw and i dont know for sure if your clip is adjustable...im only really super familiar with the first generation 400ex's. i have the whole manual in pdf if you need it.
http://i759.photobucket.com/albums/xx239/rocky_mtn_honda/TRX400EX%20Manual%20Pages/2005-2009400ex400xcarb.jpg

[alpha6164]

^^^Thanks for the info. Yes, i do have the service manual. When i took apart the carb i dont remember the needle being adjustable, but i might have over looked it completely. I have to check.

If any of the other members know please let me know.

[trx400Rider]

My 2007 is the same way as your 2005 400ex Alpha. It takes a while for it to start, then its a PITA to maintian an idle. I tryed adjusting my idle screw, it didnt raise it or lower it. What could be wrong with that? Some sorta internal problem? It really pisses me off, it shouldnt be that hard starting when its like 35 degrees out, should it?

[rocky_mtn_honda]

yea the clip isnt adjustable, otherwise it would be in these specifications...are you guys using the choke to start em?

the top table is for 2005-2009 and the bottom table is for 1999-2004, notice theres no jet needle clip position for the 2005-2009

http://i759.photobucket.com/albums/xx239/rocky_mtn_honda/TRX400EX%20Manual%20Pages/400excarbspecs.jpg

[colesdaddy02]

try to start it in the reserve fuel posistion and see how it runs. I had the same problem after it sat for a while but i cleaned the carb and gave it fresh gas.

[trx400Rider]

Originally posted by colesdaddy02
try to start it in the reserve fuel posistion and see how it runs. I had the same problem after it sat for a while but i cleaned the carb and gave it fresh gas.


Yeah Ive been running it on reserve, on like a half a tank. My idle screw doesnt work, how can i fix that? I can turn it and turn it, and my idle stays the same. Its a little low right now.

[rob_990]

it noramallys gotta idle a little bit before it changes

[trx400Rider]

Originally posted by rob_990
it noramallys gotta idle a little bit before it changes


I let it warm up for about 5 mins, and it doesnt want to idle right even when its hot.
I think im guna tear the carb down today and clean it. I gota figure out my idle screw problem to.

[rocky_mtn_honda]

i think what rob is referring to is, you dont notice the difference right away when you change the idle, you have to give it a few moments before the changes you've made take effect and it evens itself out.