My 400ex is burning oil right now. What should I do about it? Should I get a 416? Is it easy to rebuild?

 

Its not too tough to do if you have some basic tools and knowledge, and since your quad is over 5 years old (just like mine, and this ones been apart many times lol) it may very well need to be done, but you should first just determine that the oil is being burnt in the cylinder and that a worn piston to cylinder or rings are the real cause unless you are more interested in the power gains etc and are going to do it anyway.

A simple leakdown and compression test should tell you the condition of the cylinder.

One other thing to keep in mind is that if you increase the bore, and the power thru a better seal in the engine from not burning oil and most likely the higher compression you will get from a new piston is that your also working with a 5+ year old clutch unless its been changed already. I cant say the condition of the clutch componets, or how long they will last or even if they have been changed already, but if its tired etc it would be the next thing you might be working on so may as well plan on doing it up front.

Funny thing is that if you are lucky and depending on how it was ridden etc it may still be in great shape too so I guess you could get away with it also.

If your concerned about how to go about the rebuild just do some searching around the net (especially here since I know there has been threads on this many times before) and then if you still have questions post them up etc

Good luck

 

nicely said 440ex026 where at in jersey are you located I am in south jersey like right around the corner from atco raceway

 

From what I have heard, the valve guides go long before the rings or piston, so it may just be something that simple.

 

Great, I look forward to spending my money. I'm still a student right now but I'll be able to afford this stuff with my 0% student loan yay.

My 400ex is burning oil, my bearings just went again (they went in the summer and I put some cheap ones in), I messed up one of my A-Arms (I was being stupid), my rear light doesn't work (I need to check the wiring) and the front lights are dim and the starter doesn't work anymore (I think there's a short or something from the battery).

I also need new rear tires.

 

I have a 400ex too, and I was wondering what the symptons of burning oil are. Thanks

 

I am in central ocean county about 5 miles south of toms river.

 

Good thought, and I really didnt think of it, but thats prob because the ones I took out of mine when I updated the valvetrain were nearly as tight as the ones I replaced them with.

Still I have seen them where there totally shot too so its a very good place to look unless your really wanting to rebuild for more power and only using the oil thing as a motivator or excuse (what I think may be the case here too lol)

 

Jed it sounds like you have some work cut out for you in the future
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I am going to try and hit these in order/

The bearings I think your talking about are most likely the carrier bearings, and they go bad a lot for a couple of reasons. First there the wrong bearing for this application, and thats no secret either. There designed to be thin so that you dont end up with a monster carrier that robs ground clearence and just wont look nice, but this comes at the price of the bearing not being able to handle the thrust or side loads that we put on them every time we turn or slide etc. as there just isnt enough material available to do the job and eventually over time the steel fatigues more and more till it fails. Another issue is the ability for water (and usually dirty water at that) to get into the bearings and cause corrision to make them fail, or at least to wash out the grease and then they fail from lack of lubrication (normally these happen well before they fail from thrust loads, but those of us who know how to deal with the water contamination and washout end up dealing with the other cause of failure).

The "cheap" bearings are normally the inferior made ones from China, and just like most everything you find at the dollar store they were made as inexpensively as possible, and many of the things that find there way to the US are actually rejects too. If that is the same as you meant by cheap bearings then all you really did was save some $$$ as I would bet their life expentancy to be no less than the others unless you used the expensive seals from the dealer, and properly maintained them (removing them to check on their condition, and address any problems from contamination etc).

Only real problem is that they are honestly junk in my opinion (not only for the carrier either) and I wount risk my **** getting messed up running on inferior chinese junk.

If you dont want to spend the extra $$$ at the dealer then find an industrial distributor (try your local bearing house or even something like grainger) that handles one of the better Japanese brands and give them the number that is on the bearing. That way you still get a quality product, and save at the same time.

I dont know what you did to that front end, but if its bad enough see if you can afford to update here too as even if you run the stock arms a good set of aftermarket shocks (set up properly, search everything you always wanted to know about suspension here) will make you a whole lot faster than having more power.

Now judging by the info avail I am going to take a guess that you run thru water pretty often, and I bet there is a good chance that anything from the basic wiring connectors to the starter itself and potentially everything in between have some kind of corrision on or in them that could be causing the problem you are stating.

Take a look at the easy stuff first like the wire connectors, and clean them out if needed and then spray them doan with a water displacing lube for elec connections (not WD or other kerosene based stuff) and if that doesnt help then move on to the starter, and other parts.

Elec can be a pain so have patience and a manual handy as it will help you pin point the problem.

 

I guess the most obvious is the smoke, but since not all causes create the same amounts (some hardly any) the best way is when your oil level drops a lot.

If your needing to add oil, and there are not any leaks then its time to look at the internals.