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87 trx 350 question

1266 Views 12 Replies 3 Participants Last post by  retro
Hey everyone! I went for a pretty long ride today but had to cut it short because I thought my oil cooler, or the left hand oil hose was leaking. There was enough drops of oil to make me concerned. Upon getting home I removed the left hand mud shield and much to my surprise the oil was coming out of one of the breather hoses right there up high next to the frame. Crank case breather hose? Anyone have any idea why that would happen? I was cruising right along when it happened. Going about 30-32mph. Not sure what that translates to In rpm's but I'm guessing near 4000? And thoughts wold be much appreciated as I had a long ride with my girlfriend planned for this saturday. Thanks!
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Is it the fat hose that hangs in the top frame rail on the righthand side? That fat one goes down toward the cross frame under the seat to a T, then one hose from that T loops over the frame thru a holder clamp and plugs into the top of the motor next to the chain tensioner... the other hose from that T goes down to a swingarm loop where its capped with a one-way drain valve... Is that vent tube assembly the one you are referring to?
Yeah thats gotta be the one. My machine may be plumbed different than yours but it sounds like we're on the same page. First thing I would do is unhook the hose from the motor and rev it a bit to see if its blowing a lot of air/oil mist out of there or not. If it looks excessive then its time to troubleshoot the motor for the reason...

Oops, we were posting at the same time, sorry 'bout that. I type pretty slow as you can probably tell...
Is the rear diff vent hose hose hung up high under the steering head where it belongs? If that happened to me I'd be keeping an eye on the oil level in the rearend in case a pinion seal is going out or something... seems like if it can vent oil way up high, then its possible that air is getting whipped into the oil making it foam up..? Maybe its just cause you were going fast and warmed it up... like you said.

Is the viscosity of the oil pretty close to 80w that you have in it now? Anyway, glad ya got a handle on it...
Oh yeah... I remember your front diff problem from a while back now... I think I have that thread bookmarked somewhere, cause I'm interested in finding out why that happened and why the thick oil fixed it, some day. After your thread I almost took my front diff apart to have a looksee... but I don't have all the right tools to complete the job so its back on the watch list. Let us know if you learn anymore.... thanks.
Yeah I'm wondering the same thing... don't know why it would go that high if everything is normal. Stranger things have happened though...
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