Thinking about buying a 400ex

[Skerry1]

Hey guys, I need some advice. A buddy of mine has offered me an 01 Honda 400ex for $600. I'm concerned though about the amount of money that will have to go into it if I buy it. Here are the details.

It's been sitting for a couple years but was running when it was put up. It was submerged in water at some point and smokes because the rings need to be replaced. It has been bored out to a "408cc". The motor does turn over. The plastics are good but there is rust on the frame. My Uncle in Law works on atvs on the side and has agreed to work on it for me for cheap.

Here is what I think I know along with the contradictions I would like to have cleared up. The rings definitely need to be replaced. The guy selling it to me says that I only need to replace the rings. The guy doing the work says I should replace the piston as well. He also says that the cylinder needs to be bored but cannot be because it would make it too thin. Guy I'm buying it from says that it can bored up to a 440. Internet says that it can go to 416cc without a problem but will require a sleeve if I go to 440cc. So to recap, guy I'm buying it from says I can just replace the rings and clean the carbeurator and I'm ready to go, mechanic says that I would need a new cylinder, ring and pistons if the rings are messed up. My thoughts after researching on the internet, and nothing else, is that I'd like to bore it out to a 416 and replace the rings and pinion and call it a day.

What do you guys think? Recommend? Should I just turn down the deal?

Help please
Stephen

[ansimation]

I'd do it. You figure if you dump another 600 into it, that's $1200 for a decent 400ex. I just dropped my son's off at the shop yesterday to get his bored out to a 426 and some other stuff like a new timing chain/tensioner and a stage 2 cam as well. All together I spent about 700 on the kit but that's with a cam that ran me $175 ( You can find them for $130 on ebay ), new timing chain, timing chain tensioner and some other goodies you might not necessarily need with big bore kit.

I think it's worth it but that's my opinion. Hope it helps

[Skerry1]

I appreciate the advice. I can get a newer model 400ex in running shape for $1500 all day long down here though. So I really don't want to go over $1000 on this thing. My temptation is to just tell the mechanic what I want. Bore it out to 87mm, put in a this ring and piston and if something goes wrong it's on me. I hate to assume that I, someone who has never worked on an atv in their life, knows more. But all my reasearch including this forum and others says that should work. I'd love if someone could tell me what they think from the technical standpoint.

[punk rock kiel]

what do you want for 600 bucks. your lucky it turns over and runs but smokes. if everything else is half decent, buy it and fix it.

or instead of paying 600 and having to fix some things, pay 1500 buy another thats "perfect" and when something goes wrong, find a cliff and push it off.

being cheap and owning a toy that takes abuse and tends to break doesnt go together.

[Skerry1]

I never said "perfect" and trust me I understand whats coming financially which I why I'm asking for advice. I'm not cheap but I'm not going to throw away money. Since I've never done this, I'm looking for some incite into angles I'm not seeing. I never said I could find something "perfect" for $1500, I just said running. I thought this was a good deal and was ready to pull the trigger. But so many things have come up that I'm seeking advice. I never meant to seem to be complaining. So please, if anybody can offer any more useful suggestions, I would greatly appreciate it.

Thanks

[TheAwesomehonda]

On the motor i wouldn't expect to get by very cheap, you probably need to bore your stock cylinder to 416 and get new piston, rings gaskets. Also other things that may be worn out would be the cam, head/valves, cam chain, and clutch but they may also still be good.

[JOHNDOE83]

Basically, it's worth $600 in part's alone if you part it out and sell it. Rust on the frame is easily taken care of with a wire wheel on a grinder and some spray paint, as long as the brakes work well "not the pad's the actual brake's" nothing is bent or rusted through on the frame and the tire's are "ok" and the motor spins and the starter work's, it look's like a decent deal.

I have a whole running 440ex motor with valve's, stage 2 cam, heavy duty clutch and 450r carb Im gonna be selling here soon if your interested. It will probaly be more convienent to rebuild your current motor tho...

Offer him $450 and see if he bite's, if not wait a week and offer it again, if he says no again say $500 is all I can afford cause I have to rebuild it. If he says no again...well.....only you can decide if it's worth $600, it will still be a good deal in my opinion.

ALSO!!! it is a good time to get rid of the EX motor and build a hybrid if you really wanna get down.....:macho

[Skerry1]

So that's what you would do if it's possible? Bore it to 416 and replace then rings and pinion? I know that this could completely change if we open it up and find a bunch of damage. I can get 416 ring, pinion, gasket set for $140 and the guy that's fixing it has a machine shop so he can bore it. This seems like the best solution to me but I'm being told it can't be done. That 408 is as big as it can get without replacing the cylinder. Even if I want to replace the cylinder, I can get all the parts for around $350.

Money is only in an issue in the sense of: "Is it worth it to spend this amount of money on an 11 year old vehicle that will likely have many more problems coming soon?"

I understand I'm dealing in what-ifs and nobody can assess the bike without looking at it. I'm just saying, based on the information I have. Would you buy it?

Thanks

[Skerry1]

Originally posted by JOHNDOE83
Basically, it's worth $600 in part's alone if you part it out and sell it. Rust on the frame is easily taken care of with a wire wheel on a grinder and some spray paint, as long as the brakes work well "not the pad's the actual brake's" nothing is bent or rusted through on the frame and the tire's are "ok" and the motor spins and the starter work's, it look's like a decent deal.

I have a whole running 440ex motor with valve's, stage 2 cam, heavy duty clutch and 450r carb Im gonna be selling here soon if your interested. It will probaly be more convienent to rebuild your current motor tho...

Offer him $450 and see if he bite's, if not wait a week and offer it again, if he says no again say $500 is all I can afford cause I have to rebuild it. If he says no again...well.....only you can decide if it's worth $600, it will still be a good deal in my opinion.

ALSO!!! it is a good time to get rid of the EX motor and build a hybrid if you really wanna get down.....:macho

This is what I'm looking for,thanks for the response.. He's pretty dead set on $600 and that seems like a good deal from what I've seen. I don't need anything fancy right now, I just want to crank and ride it. I'm a beginner. I'm told this is the best option as a bike that I can grow with. What I don't want is something that breaks everytime I try to ride it.

[dxcody]

Originally posted by Skerry1
What I don't want is something that breaks everytime I try to ride it.

As long as you dont ride like me, that wont happen! :D

[JOHNDOE83]

Originally posted by Skerry1
This is what I'm looking for,thanks for the response.. He's pretty dead set on $600 and that seems like a good deal from what I've seen. I don't need anything fancy right now, I just want to crank and ride it. I'm a beginner. I'm told this is the best option as a bike that I can grow with. What I don't want is something that breaks everytime I try to ride it.

Ya, the 400ex is a extremely reliable Atv when it's taken care of.

Other then the motor issue's the only other issue you may have would be the swing arm bolt being froze in place "which is fixable" we've all had stuck swinger bolt's, the other thing Would be the axle bearing carrier, but if it roll's fine now its probaly ok.

I had a friend who bought a 250xs atc for $35 yes $35 and we got it to run but it smoked bad, he rode it everyday for a year with it smoking like that and he sold it for $500.

If your a beginer trying to learn, get it running with it smoking and replace the little thing's like brake pad's and bearing's and cable's and re-painting while your getting the feel of the ATV and learning to ride it.

If you go to 416 you'll need to re-jet it for sure also, which is pretty easy and there's a ton of info on this site on how to do it.

post pics of it after you buy it:D

[Skerry1]

Haha, dxcody those types of breaks I can deal with lol

Would riding it with it smoking cause any other damage? I thought about doing that and then ultimately just replacing the cylinder,pistons and rings. I'm certainly not going to be going too far on it and I could care less about smoke.

Thanks

[ansimation]

Originally posted by JOHNDOE83
Ya, the 400ex is a extremely reliable Atv when it's taken care of.

Other then the motor issue's the only other issue you may have would be the swing arm bolt being froze in place "which is fixable" we've all had stuck swinger bolt's, the other thing Would be the axle bearing carrier, but if it roll's fine now its probaly ok.

I had a friend who bought a 250xs atc for $35 yes $35 and we got it to run but it smoked bad, he rode it everyday for a year with it smoking like that and he sold it for $500.

If your a beginer trying to learn, get it running with it smoking and replace the little thing's like brake pad's and bearing's and cable's and re-painting while your getting the feel of the ATV and learning to ride it.

If you go to 416 you'll need to re-jet it for sure also, which is pretty easy and there's a ton of info on this site on how to do it.

post pics of it after you buy it:D

I probably sold you that ATC if you live in the acreage and it was over 10 years ago that you bought it at a yard sale on 130th

[JOHNDOE83]

Originally posted by ansimation
I probably sold you that ATC if you live in the acreage and it was over 10 years ago that you bought it at a yard sale on 130th

OMG thats hilarious.... I live in the acreage by 130th:blah:

That 3 wheeler was in my friends yard for years, this just happend about 3 years ago when my friend purchased it from another friend off of 110th and persimmon area. He may have got it from you bacK then and just never fixed it.

Man, its a small world huh?

[Drfat400ex]

Originally posted by Skerry1
So that's what you would do if it's possible? Bore it to 416 and replace then rings and pinion? I know that this could completely change if we open it up and find a bunch of damage. I can get 416 ring, pinion, gasket set for $140 and the guy that's fixing it has a machine shop so he can bore it. This seems like the best solution to me but I'm being told it can't be done. That 408 is as big as it can get without replacing the cylinder. Even if I want to replace the cylinder, I can get all the parts for around $350.

Money is only in an issue in the sense of: "Is it worth it to spend this amount of money on an 11 year old vehicle that will likely have many more problems coming soon?"

I understand I'm dealing in what-ifs and nobody can assess the bike without looking at it. I'm just saying, based on the information I have. Would you buy it?

Thanks
Whoever said that you will need to replace the cylinder for a 416 is wrong, you can use the stock cylinder and sleeve for up to 440 as far as I understand.

[dxcody]

Originally posted by Drfat400ex
Whoever said that you will need to replace the cylinder for a 416 is wrong, you can use the stock cylinder and sleeve for up to 440 as far as I understand.

I dont think you can have it bored to a 440, but i might be wrong.

Either way though, you can bore from 85-88 MM with no problems.

[Drfat400ex]

Originally posted by dxcody
I dont think you can have it bored to a 440, but i might be wrong.

Either way though, you can bore from 85-88 MM with no problems. No no actually I think you are right, the 440 might require resleeving and overboring the clyinder walls? Lol never planning on doing a 440 unless I have to so let's let someone else chyme in about that. Anyways you can do 416 fine.

[CJM]

440 needs a special sleeve.

If you want it, Id offer 450 like John said and see where it goes.

If you can do the work yourself or pay a cheap price for the person to repair:
-Piston 120
-Gaskets 35
-Bore job 50-75
-Might as well do a hotcam stage 2 for 130
-Misc.

Figure in total misc your gonna need 300-500 bucks worth of junk more than likely.

Do a 416 kit, new piston, cam and whatnot. Id also check the timing chain, tensioner and guides as well.

[Skerry1]

Thanks for all the responses guys. I think I'm going to go ahead and just get it running then decide from there. I'm leaning toward just get the full stock cylinder kit. I don't think I need the extra horses but I can just get it running and see how it feels. Like was suggested, I'd also like to focus on the other minor problems that will probably show up with a used bike. Thanks again for all the advice. I'm sure I will have more questions in the future.

[dxcody]

Originally posted by Skerry1
Thanks for all the responses guys. I think I'm going to go ahead and just get it running then decide from there. I'm leaning toward just get the full stock cylinder kit. I don't think I need the extra horses but I can just get it running and see how it feels. Like was suggested, I'd also like to focus on the other minor problems that will probably show up with a used bike. Thanks again for all the advice. I'm sure I will have more questions in the future.

I have a good stock cam if interested :)

[Skerry1]

Always interested for the right price ;)

[Skerry1]

Alright guys, I've decided to get the joy out of doing the work myself on this thing. The first thing I'm going to run into is the carb. It's been sitting up for 2 years with fuel in it so it will definitely be gummed up.

Should I?

A.)take the carb apart and clean it real good?
B.)take carb apart clean and rebuild it?
C.)Replace the carb with a new one.

Next I've decided to go ahead and address the rings now. I will prob go ahead and replace the piston as well. If the cylinder is scoured, that's when I have a decision to make. It's bored to a 408 as I mentioned before.

Options(add them if you know of anything else)

A.)Bore to 416cc and replace ring and piston(Does this require a sleeve?)
B.)Replace with new cylinder and if so which size(400,407,416,426,440).


I'm thinking about going with the new 440 cylinder kit, wiseco for $350 on ebay. Then a Hot Cam stage 2 $127 on ebay. I'm worried this might be too much power for a beginner but I also don't want to do this again in 2 years.

[CJM]

Your going to need to buy a carb rebuild kit and find a yamaha dealer and buy the carb dip they sell (or berrymans thats sold at walmart also works pretty good). Replace EVERYTHING inside the carb, make sure the jets are clean and not clogged, check the accelerator pump as well. Replace the needle float as well as check the float to make sure it still floats. May also need to replace the rubber liens as they dry out and crack.

As for the piston, buy a 416 piston and have it bored, you dont need a new sleeve. In 2 years your going to have to bore it again if you ride it enough anyways and a 440 is not something for a beginner and also must be jetted right or you will have issues. Also with a 440, should you have to bore it you cant-you need a new sleeve.

Buy the hotcam stage 2 now as well, the stock cam sucks.

[Skerry1]

Alright guys, I've got it. Now it's time to figure out some issues. We were able to get it started but had to push start it. The starter was spinning but the bike wasn't firing up. It seemed fine when he was on the gas but it didn't want to idol. Also, after we finished riding fuel dripping from the carb. I'm thinking maybe there was some clogging somewhere? Anyway, this is what I've come up with solutions.

Number one, I'm planning on rebuilding the carb. I'm hoping that will fix the idoling problem and will allow me to detect what's causing the leaking. I have basic mechanical skills but I've never done this, is it difficult?

Next, there seems to be a problem with the starter clutch. The sprocket coming out of the top of the engine case that it's supposed to spin just spins freely. I've heard this is prob a one bearing. If so, do I replace the entire assembly or is there an actual bearing I would replace? How difficult is it to get to all this?

Thanks
Stephen

[JOHNDOE83]

You have a clogged pilot jett causing you not to idol, you have a stuck float and needle ceet causing you to leak gas. A good rebuild kit should clean all this up. Any atv that sat for some time will have the same issue.

The starter clutch free spining? I believe its suposed to free spin until you try to start it, then it engages the flywheel.

If you paid $600 and thats your only issues so far, you got a really good deal.

[red200040ex]

When you tear into the carb replace the pilot jet with a size 42 as well.

[Skerry1]

Thanks John, my concern with the carb rebuild is jetting it once it's complete. I've never done it and everybody makes it sound like a tough process that can create lots of problems if done wrong. I hate having someone else do the work because I won't learn anything but I don't want to screw this up either.

As far as the starter clutch, it's not engaging. You can hear everything spinning but it doesn't even try to turn over.

Thanks Red,

What's the benefit of size 42?

[CJM]

Pilots too lean from the factory, 42 will make it MUCH easier to start.

If the starter clutch is bad and just spinning then your gonna need all the parts for that then. Its not a super cheap fix but it wont cost an arm and a leg either.

[Skerry1]

Which brand/style pilot jet should I get for the stock carb? Also, did you guys have any recommendations for the the rebuild kit? There are a bunch on ebay but I'm not sure if they're any good.

[JOHNDOE83]

Call www.jetsrus.com they are the best for stuff like that.

The best meaning they will make sure you get a oem or oem type kit, not aftermarket junk.

Check out their FAQ section also for some great "basic" jetting info.

[Skerry1]

Thanks for the advice guys, I'm ordering the parts and rebuilding the carb next weekend. I still have to dig in and figure out what's wrong with the starter clutch. If the battery is low, could that prevent it from engaging?

[Skerry1]

Well I finally got the bike here to the house. First focus is going to be the carb, I'm going to pull it off this week to rebuild it. Then I'll be looking to fix the starter clutch. Also, it looks like I'm going to need some tires for the front at least. We were able to fire it up when I went and got it. He thought there was smoke before but we didn't see any.

Here are the specs from what I've been told and what I can see.

Motor has been bored to a 408 with a Hot Cam Stage 2.

Alien DMC exhaust

Lone Star rear axle that was apparently chrome at some point, now has a nice color I call rust. lol

A couple of pics



http://us.mg5.mail.yahoo.com/ya/download?mid=2_0_0_1_25355278_AI5XimIAAK3HT9T5mgxQ fRYMlyE&pid=2&fid=Inbox&inline=1

http://us.mg5.mail.yahoo.com/ya/download?mid=2_0_0_1_25356001_AI1XimIAALpNT9T5sgBm GnROMjg&pid=2&fid=Inbox&inline=1