Need some help with a dead 400

[boggerman]

First off, the bike is my sister's, so I don't really work on it. But it is beyond her or my dads comfort level now. It has not seen much riding for a while, but dad runs it up and down the driveway once in a while to keep the battery charged and fluids stirred up. Now to the problem - it won't start anymore. Not on the booster or anything. It just cranks and cranks, but no fire. Where do I start? I am assuming valve lash needs adjusting, as it probably has not been done since she has owned it (5 years or so). What else? What problems do I look for? It is a bone stock 2000 400EX.

[mr._bowtie]

First thing to check is make sure its getting spark... Take the plug out and lay it on the frame, crank it and see if its sparking. Ifnot replace it and youll be good. If so, then its a fuel problem which is more likely if its sat for a long time. Id say that the carb has old varnished fuel in it and needs to be taken apart, soaked and cleaned completly. Its not that hard just pay attention to how it came apart, not many pieces. It help to have an air compressor to blow through the just and orrifaces to clear them out good.

If neither of those works then well have to get more serious.

[moorhous]

^^^ agreed

[KXrider656]

check for spark and change the plug. i seen this problem a million times, usually the plug does the trick

[boggerman]

Thansk for the quick replies. Unfortunately, both the plug change and carb cleaning have been done and neither did the trick. What next?

[moorhous]

ok You change the plug but did you check for spark? how old is the gas?

[boggerman]

Checked for spark and it looks strong. I cannot say how old the gas is, but probably pretty old. Is there someplace to find the service manual online for the 400?

[moorhous]

there may be but I dont know it whats your e mail I have it on disk I think I could email you it

[Honda#4]

dump the old gas out and put new in, if you did all that then I would suggest getting your valves checked.

[400EXTRA]

Originally posted by mr._bowtie
First thing to check is make sure its getting spark... Take the plug out and lay it on the frame, crank it and see if its sparking. Ifnot replace it and youll be good. If so, then its a fuel problem which is more likely if its sat for a long time. Id say that the carb has old varnished fuel in it and needs to be taken apart, soaked and cleaned completly. Its not that hard just pay attention to how it came apart, not many pieces. It help to have an air compressor to blow through the just and orrifaces to clear them out good.

If neither of those works then well have to get more serious.

agree also

[KXrider656]

idk man, i would do a carb cleaning, nothing could have gone wrong with the motor if it has just been sitting for a while. its not uncommon for the gas to varnish up, and ebay will get u a 400ex repair manual cheap, they are all identical from 99-04 so it shouldnt be a problem

[GPracer2500]

Try some starting fluid maybe? If it wants to run with starting fluid then I'd zero in on it being a fueling problem.

[flauge]

^^ x2. Ive found that is the best way to narrow things down.

[boggerman]

Thanks for all the replies. I'll try the starting fluid and see if it tries to light. It's very possible that the carb is gunked up considering how much it sits (shame really, it's a pretty decent bike to just leave sitting).