400EX wont start

[ben98gs]

Let me start off by saying I know tons about cars, but NOTHING about quads.

I have a 2001 Honda 400EX that I got through a trade. My better side told me I should just sell the car and not trade, but wanted to help the guy out. When the guy pulled it off the truck, it fired RIGHT up and I took it on a ride. Rode great, pulled the front wheels easily off the ground and everything.

Over the next few days I started it up and took it for a few more rides around the neighborhood, ran great. Then I parked it so that I could finish rebuilding the motor in my Saturn to get it out of the garage. Quad sat for about 2 weeks. Went to start it and (again I know/knew nothing about quads) and it would just crank, but not fire. Finally someone mentioned the choke. Turned on the choke, and it fired up, but did not want to idle... If you would hold onto the gas a bit and let off it would backfire pretty bad. I tried to get it warmed up thinking it was just being tempermental when cold like some of the quads I have ridden in the past were. Even after warm though, it would not idle.

Parked it again and it sat for about a week. Now it will crank still, but I cannot get it to fire at all. Seems to smell like gas, so I thought it might be flooded, pulled the plug and cranked it, let it sit for about 30 minutes with the plug out hoping it would be good, but even after cleaning the plug and reinstalling it, the quad still wont fire and exhaust still smells like fuel.

What should I do to start trying to solve this problem?

Again, it is a 2001 400EX has HMF header and pipe and is jetted. That is really about all I know about it.

[gcart2]

about the smells like gas part... that just means its most likely bought time to pack your exhaust. that cost like 10 bucks to do.

[JBDIV]

ben98gs --> Congrats on your inheritance, I think!

First, let me say this. 400ex' can be cold natured as you know what. And depedning on the weather, elevation etc. they can sometimes be very difficult to warm up.

Anyway, here are my suggestions:

Buy a mannual for this bike. They are true time savers. You'll likely need it to solve this problem anyway.

Next, inspect the plug for fowling. You being a car guy know this is one of the best onboard diagnostic tools for measuring your bike's health. Look for excessive carbon build up, oil fowling etc.

Given that, I would do some good old fashion maintenance on this bike given that you do not know its history. All of which will likely fix this problem anyhow.

After inspecting the plug, regardless of its condition get a new one.

Check the plug wire. Could be worn out and is easy to replace.

Remove the air box. Check the air filter and inside of box. Clean and or replace the filter as necessary.

Remove the fuel tank. Drain it and rinse with new gas. Yes, you have to take off some body panels but, it is not hard.

I would remove the carb. Remove the drain plug and bottom plate. Check the inside for dirt/grit. If you've purchased a mannual by this point. I would remove the pilot and main jet and check the sizes. They could very well be wrong and will most certainly cause starting problems if they are. Clean everything and replace.

While you have all this off, check your valve clearance and cyclinder compression. Not hard to do again if you have a mannual and basic tools. You might want to get some angled feeler guages to help here.

Change the oil and oil filter. Don't forget to clean the screen in the bottom of the oil resevoir. The mannual will tell you this. Oil is cheap, engines are not :-)

If you haven't found anything majorly wrong, put it back together and give it a try. If nothing else you'll have a good clean starting point for more in depth diagnosis of the problem.

Good luck and let us know what you find!

[gmoney]

First before you start messing with everything else, make sure you are getting spark. If you smell gas then there is gas getting to the engine. Also make sure the Off/Run switch is in run.

[ben98gs]

I might start tearing it down tonight then as I am waiting on parts for my car. There is a lot of just "dirt" built up on the outside of the motor.

Plug did not look excessively fouled and I was planning on getting a new one anyway, but was hoping to at least get it to start again and see if that might have been the problem.

Just a little frustrated that it ran fine and now just wont start after sitting.

[ben98gs]

Update, got it to start again, and it will fire right up... But it still falls on its face and dies and also backfires when you let off the gas after it had revved up a bit.

Air filter is FILTHY, it is a K&N and I am going to buy a recharge kit tonight when I get the new spark plug.

Any other ideas...

I have not done all that you mentioned, JBDIV, but working my way down the list, I just have too many other projects that take priority over this thing. I am just trying to get it running to sell it.

[the Z Man]

I had a similar problem, I had water in my gas, just use your overfill line out of the bottom of the carb, stick it in a clear bottle and turn the screw (flat) at the bottom of the carb shifter side counterclockwise til fuel comes out, inspect for water, also pull the 17mm plug from the very bottom of the carb, turn off the gas first, look for debris..

[ben98gs]

Well, I pulled the carburetor completely apart and clean it all. I think the jet "might" have been clogged. I sent some compressed air through it backwards because I really could not see through it, and then I could see about a needle sized hole after sending the air through it. I have not gotten it completely back together. I hope to do that today.

Will let you know.

Ben

[my88r]

Originally posted by ben98gs
Well, I pulled the carburetor completely apart and clean it all. I think the jet "might" have been clogged. I sent some compressed air through it backwards because I really could not see through it, and then I could see about a needle sized hole after sending the air through it. I have not gotten it completely back together. I hope to do that today.

Will let you know.

Ben

ya it sounds like the carb is gummed up. make sure you drain the float bowl when siting.:macho

[ben98gs]

How do I do that?


As for everything else, I got it all back together and changed the oil. Fired right up. I had adjusted the idle screw back to the point that it was not pushing the throttle and it ALMOST wanted to idle. A few turns of the screw and it idles perfectly fine now.

Thanks for all the help.

my88r, or others, what do you mean by drain the float bowl when sitting??? how do I do that? Is this something I should do anytime I am not going to drive it for a week or so?

Thanks again.

[JOEX]

Originally posted by ben98gs
...
my88r, or others, what do you mean by drain the float bowl when sitting??? how do I do that? Is this something I should do anytime I am not going to drive it for a week or so?

Thanks again.
To drain the bowl I usually just turn the gas off and let the motor idle till it dies.

[my88r]

Originally posted by JOEX
To drain the bowl I usually just turn the gas off and let the motor idle till it dies.

yep that's what i do. or there's a bolt on the bottom of the carb. but be careful as it has gas in.:macho

[ben98gs]

Sounds easy enough... Thanks for the tip guys.

And everyone else, thanks for the help.

[JBDIV]

Ben,

Glad everything worked out! Maybe you'll keep it now and get some fun out of it.

Cheers!

[ben98gs]

I wish... Besides having nowhere to ride it, we (my wife and I) recently found out we are expecting. Too early to know the sex, but our first son/daughter will be born in May. I have too many other projects and just traded the car for this 400EX to help the guy out (as he really needed a car to get to/from work). The quad was worth more than the car anyway.

I do have a blast riding it though and if I lived out in the country a bit more and owned more land, then I would probably definitely keep it.

[JBDIV]

Ben -- Congratulations! That is great news! We had our first child this past October -- a girl -- and man, it is a wonderful thing.

I understand your points about keeping the bike. Mine sat in the garage untouched a lot more this year than I would have prefered :ermm:

Well, best wishes to you and your growing family. Take care and maybe we'll meet up on a trail one day!

Cheers!

[ben98gs]

Thanks. With our neighborhood association we are not allowed to have mini barns and if I store the quad then I cannot park a car in that side of the garage. I would rather see someone enjoying it then it just sitting.

Thank you again for your wishes. There will be plenty of time for me to get another quad (or two) when my child(ren) are old enough to enjoy it with me. Congrats on your daughter getting ready to turn 1 here next month too.

Thanks again for all the help, I knew it was not anything major, I just needed to take the time to sort it out.