I'm new to the whole working on a quad, my friend gave me his 2001 Honda 400ex, i need to take the carb off and clean it out, since its been sitting over a year, how hard is it to clean it up? anyone do it out there that can give me some tips! Thanks guys!

 

Welcome to the forum, and welcome to ATVing.

If you are going to do your own work, I'd highly suggest getting a manual. Preferably the factory manual, but clymer or hayes aren't bad either.

Generally, once you've got it removed, spray the outside off with some cleaner, pull the bottom float bowl and take the hinge pin and float off. Pull the top apart, and the side cover. You might also want to remove various jets.

Then use a good carb cleaner like B12 Chemtool to blow out all jets and passages. Don't forget to hit any passages inside the bore of the carb. Follow by compressed air. Clean up the float bowl and anything else that needs it.

If the seals look good, and the float needle has a smooth V without ridges, you should be good to reassembe. If the seals or anything else look iffy, snag a rebuild kit.

This page shows a general exploded view of your carb.

http://www.bikebandit.com/hous...urtrax-ex-2001/o/m2658

 

Basically i'm thinking that i need to do a thorough clean with the carb, because the fuel overflow tube keeps pissing gas as soon as you turn on the gas ****, am i right thinking that maybe the float inside is jammed up? im hoping that cleanin the carb will fix the problem. Think it will??

 

If gas is running out of the overflow, most likely the float valve is gummed up or has some debris in it.

You also need to take a good look at the float needle. The end should be a V with smooth sides. If it has a groove, then it needs replaced.

May as well clean everything in the carb as long as you have it apart.

 

Few tips.
When removing the float pin, be careful that you do not snap off the pivot towers when removing pressed in float pins. I use a nail set for removing them. (Looks like a punch but spring loaded that when you push on it it snaps and leaves a dent in a flat surface) The sudden snap loosens float pins without breaking the pivot towers which happens when pounding pins out with a hammer.
Completely disassemble the carb if you intend on spraying carb cleaner through it. Especially if it is a vari venturi carb (diaphram under the top cover. The diaphram can become distorted by carb cleaner or blown if compressed air is blown into the carb passages.
Spray carb cleaner on a Q-Tip and clean the inside of the float needle seat. Probably a good idea to use a golf tee pointed end, sticking it into the float valve seat and spinning it back and forth with a little pressure to smooth out any imperfections in the float valve's tip mating surface.
When removing the fuel air mixture screw, turn in counting the turns until lightly seated first and remember the setting for reinstallation. When removed, account for the mixture screw, spring, small washer and o-ring. The washer and o-ring normally stay stuck in the fuel air mixture screw seat. If not accounted for and carb is blown out, the parts will most likely never be found. Fuel mixture screw screw installed with out them or installed with the o-ring and washer in the wrong position will cause start and driveability issues. O-ring goes in the carb first followed by the washer, spring and then fuel air mixture screw. A small bent tipped wire will come in handy to remove stuck o-ring and washer in the carb.
Don't forget to remove the main and pilot jet and make sure they are not restricted.
If you swell the venturi diaphram with carb cleaner, run it under hot water and dab it dry with a paper towel. Shop rags do not work for this. The hot water expands the rubber's pores and the paper towel will extract the carb cleaner which are swelling the diaphram. Repeat if the diaphram is too big to fit the groove in the top of the carb. Diaphrams that still are too big to fit the groove correctly may need to be run under hot water then put in the freezer for 1/2 hour to shrink them back to origional size. Install into the carb as soon as removed from the freezer and install spring and diaphram cover. Just a little tip not a lot of techs know about. It works on accelerator and fuel cut diaphrams also although most atv carbs do not have them.

Hope this helps


----- Gimpster -----

 

not to hijack this thread but will that trick with a swelled diaphram work with a swelled float bowl gasket/o ring? i took my float bowl off my 250x and the seal swelled up and wont fit into the groove on the bowl.

 

Good advice there.

With the O ring, you might give it a shot, but if it is at all iffy I'd be for getting a rebuild kit that will come with all of those seals.

 

Thanks guys for all the good advice, ill let you know how it works out..

 

not to hijack dvirdone's thread but I have the same issue (must be spring cleaning time). My Honda is older 86 TRX 350 which has a fuel pump. Here is my question- the manual gives me a float height (which is off, low about .200) how do I set that on an all plastic float? Everything I've every worked on had a metal tab to bend for this setting. Follow up is what would have changed over the winter, it worked great when I parked it??

 

I don't think I've ever found a plastic float one that was out of spec, so I can't answer that one.

As far as what happened, the more volitile compounds in gas evaporate first, leaving heavier varnish type stuff behind. Gas goes stale faster in smaller quantities, and when exposed to air (like in the carb float bowl). The problem can be especially bad if you leave the gas on, as more gas enters the float bowl to make more varnish.

I've found that even if a rig is only going to be laid up for a week or so, shutting the fuel off and either running the float bowl dry or drain the carb and it will start much easier. For longer term, some Honda fuel stabilizer (don't use more than recommended) in a full tank (to prevent condensation) and a drained carb will keep the gas fresh, and prevent jets and so on in the carb from getting gunked up.