I bought this bike used 2 months ago with 1700 kms on it (2001 350 4X4). I changed the oil/differential/rear end fluid on Friday. When I checked the airbox, there was about an inch of oil in the bottom, so I drained it out and cleaned up the airbox. Put 2 Litres of oil in the bike and it showed full. Took it out today, did about 80 kms of driving and again there is oil in the air box, not as much as last time though. I did not flip it over or have it on it's side or anything, is this normal? It still shows full.

 

Could it be from the air filter? Usually its a green or blue color, if its foam oil.
If not, then its probably coming from the crankcase breather.air box That would be #16 in the pictoral.
I dont have a rancher, so i dont know, but is 2 liters too much?

 

Both my Ranchers do this to some extent. More some times than others, but never anything close to an inch of oil! Mostly just a little neuisence amount in the bottom of the box. You are right, it's from the carankcase breather. (As I recall, they put a baffle in the later models, that was supposed to help????) Anyway, if you have a factory foam filter, it usually isn't that bad, but I have a K&N, and it sometimes gets all over my outerwears.

I would say an inch is a fluke thing??? Keep riding it and see if it is that bad consistently.

 

An inch of oil???!!!!! Do a compression, or better yet, a leak down and see where the air goes. Sounds like you will have a hurricane coming out the breather?

 

It's not smoking or anything, I'm pretty sure the compression is fine, there is lots there if I have to pull start it. I'll keep an eye on it and see if it get's worse. Maybe it was slightly overfull with oil or something.

 

If it was over filled then it could go into the box. But an inch of oil is a bunch!!! It is always a good idea to do a compression on a used machine or even a new machine. If it's a used machine that you don't know the histroy, you really should do it. Everything I own I have a record of the compression. I do this to monitor the health of the engine. That way if engine seems a bit lazy, I can check the compression and see if a rebuild is in order or if just a simple tune-up will wake it up.
About your problem, I just don't know how the breather set up is done on your quad. Some of the newer engines are getting very complex with crank case breather systems. Some have computer controlled solenoids; some have simple breathers. Quads and bikes are starting to have smog systems put on them. Sad but true, things are getting complex. Maybe some Honda tech can point you in the right dirrection if your compression turns out ok. Sorry I can't help you more.

 

I bought the bike from my brother in law, of the mileage he put on it, I was with him for 3/4 of it and it wasn't hard driving. I'm starting to think 2 litres is a hare too much. I ride it hard, high rpm's, and the occasional jump. I'll lower the level to between the upper and lower mark and see what happens.

When I found the inch of oil in the airbox, I thought it was from when I did put it on it's side once, which prompted me to change the fluids for peace of mind. This time, there was maybe about 1/8 of an inch in the bottom of the box. I asked the bro in law when the last time he checked the air filter, which he couldn't remember so the oil could have been there for months, possibly a year. Either way, I'll report back my findings this weekend.

 

I have an 03 rancher fm manual shift. when I hillclimb or do wheeles the air box gets oil in it. So I took it to the dealer and they said it was normal and not to worry.

 

i always hear on sites and from mechanics that if you put in too much oil it can get pushed into your airbox, i dont no if it can happen to that extent tho. its just a thought.

 

now that u've said that, I rember the dealer mentioning that the new hondas don't like the oil all the way up to the top mark on the dipstick, it should be half way between the upper and lower level so, I was told.