I sure hope someone here can help me.

I have 2 TRX300EX quads, both stock except for DG pipes and exhaust on both. One is a 96 and the other is a 98. Both run great with one exception. The 98 blows oil out of the crankcase breather tube (i think that is what it is called).
It is a tube that runs from the bottom up over the top of the engine. There is a T connection that looks like it goes into the cylinder wall. The top of the tube is open and the bottom is crimped. Oil blows out of the top of it when the throttle is wide open in any gear. It ONLY does it when it is wide open and the gear is topped out with max rpms. I can ride all day long with no problem, but as soon as someone tops out the rpms in say seecond gear to climb a sand hill, oil sprays all over the place.

I changed the oil, filter and plugs before I went out to Ocotillo Wells over the weekend and I also noticed that when I got home that the oil in the 98 is a lot darker than the 96. Smoke also comes out of the tube as well when idleing after a ride. They were both rode about the same amount of miles as well.

I don't have any of these problems with the 96. I used the 10W-40 Honda oil. The plugs look great, no oil on them or any fouling. I have been told that this is just normal and that it just does it cause of such high compression and it needs to be releived someplace so it shoots out of the tube. That seemed to make sence to me because that was what I have been told by a couple of shops, but now I wonder about it after seeing that the oil is darker that the other one. I have also been told it could be too much oil, but I don't know how that could be since it is just up to the line and I put in the same amount as the 96 and that one never blows oil or has smoke coming out of the tube when it is idling after a ride.

HELP!! Anyone have any ideas what could be causing this? If it IS normal then thats fine, I will live with it. I just need to know if it IS normal. My concern is that something might be wrong which will lead to bigger problems and a lot of money to fix down the road. I am trying to avoid just taking it in to a shop and paying to have them give it the once over and just telling me that there is nothing wrong.

Thanks!! and sorry for the long post, I am just frustrated.

 

My guess would be that your rings are worn and that you are getting some blow-by causing this to happen. It may also be worn valve guide seals. How much time is on the quad? Was it broken in properly? You may need to rebuild your top end. Let me stress that this is a guess based on a LITTLE knowledge. Someone with more experience will give you a better and or different answer that I will use to expand my own knowledge [img]i/expressions/face-icon-small-wink.gif[/img]

 

I bought it used from a dealer, so I don't know how it was broken in or how much time it had on it. It looked really clean and runs great though, except for the oil thing. If the rings are worn, would'nt the plug show signs of oil fouling though?? Everytime I look at it, it is always clean and dry with a nice tan color.

 

If the rings were worn, you would notice a lose of power, smoking, and fowling of the spark plug. It sounds to me like a crankcase breathing problem. Have you taken the hose off the crankcase and inspected the vent hole to make sure it is free from gunk buildup and that nothing is restricting ventilation flow. Also make sure that the restriction is not in the tube or plastic T. You mentioned that it was pinched off in the bottom??? That would cause the problem.

 

The first thing that I would chech is the vent tube and make sure that it is clear. Next I would check the rings or valve guides. I've seen that kinda thing before on my old XR250.