Oil pumping out?

Before I jump in, let me re-introduce myself. I used to be on this forum a lot when I turned a 1981 XJ650 into a bit of a custom bobber. It looked like this when I traded it off for another project:



But, things come full circle. Tomorrow I am going to look at a 1982 650. The owner/seller says that he was revving it up in the driveway when "oil started pumping out of the oil box" so he shut it off and wants to sell it.

I have zero plans for any customization, rather want to keep it stock.

The pictures look pretty decent and the bike has 7700 miles on it. I don't know what he's talking about...oil box??? Maybe it's pumping out the crankcase breather through the air box??

Can anyone tell me what may be going on? Thanks in advance for any hlep on what to look for.

 

If the oil is coming out of the air box, the crankcase is full of gas from stuck/flooding carbs. Don't run the bike anymore and get the gas/oil mix out of the crankcase ASAP.

Mn

 

That's what I'm thinking. I'll take a whiff of the oil fill hole and see if that's the issue. Seems it's always the carbs with these bikes! ha ha. Oh boy. Here I go again.

 

Welcome back !!
Actually, this idea of pumping oil out just came up, and it was suggested that gas was in the crankcase, which starts to boil off when hot, blowing oil into the airbox.

The gas comes from a faulty petcock AND a dodgey needle/seat/float at the same time.

If so, should be an easy fix, as you're buying a "runner" with minor problems.

(MN beat me !)

 

The carbs on these bikes are why you see alot of low mile ones sitting around. The carbs screw up and if you were to take the bike back to Yamaha back in the day, it would be too expensive to fix. It was alot easyier to leave sit in the back of the garage until the owner had some spare cash to spend that never happened.
Be carefull when you unscew the oil fill plug , it might just pour gas out of there.

MN

 

I hope that is the problem. I am very comfortable working on these carbs. I should be. I had the carbs off and apart so many times on my '81 that I think I could have done it blindfolded. Of course that was the one advantage of the pod air filters.....I could have the carbs off the bike and on the bench in about two minutes, tops.

If it looks decent, and I believe the mileage, 7700 is nothing.

 

Some would say, ... that, ... that is the ONLY advantage of having Pod Filters.

 

hopefully its the gas thing .It almost sounds like exsessive back pressure if the motor is forcing all the oil into the air box do they have a 2nd breather hose most bikes do that might be clogged .has the bike sat for a long period of time the rings could need to re seat themselves. was the oil overfilled i have seen that happen more then 1 time. change the oil first see if there is exsessive pressure there where it goes in the box

 

I know. Now.

Over the last couple years I have become more and more of a "stock" guy. The bike was fun and ran ok, but never great. I went through a lot of jetting combinations trying to perfect it. As you know, I spent some time chasing my tail.

QUICK story about pods....my brother-in-law has a 1979 Honda 750 Custom (or whatever the model is...) that came with pods. They are the ones that are kind of ugly, with a foam outer filter element. Over the winter a couple years ago he brought it to my place and we did a bunch of work to it. He wanted it to be awesome in the spring. One of the things he bought were the typical steel-mesh pods. Well, spring rolls around and he comes to get his bike. He starts it up and it sounds like crap. He goes out and rides up and down the road in front of my house. It sounds like crap. He swears it needs this, that and the other thing. I told him to put the old air filters back on, they were more restrictive. No no no. Can't be. He rides off to do whatever. About a week later he calls me..."Hey I fixed my bike. You wouldn't ever guess, but I put my old air filters on and that's all it was". And he was serious. Like I had never said a word! :roll:

 

How do you get gas/oil mix fom crankcase? Drain, new filter...run a min, drain and new oil?

 

You change the oil and filter, DO NOT run the motor without oil in it.

Just do another oil change within a couple hundred miles of getting it fixed.

It may take multiple oil changes to completely get rid of all traces of gasoline, so don't extend the oil change intervals right away.

 

Have a good look at the front brake rotors. If it is low mileage there should be no lip or very little lip on the outer edge of the rotors if they are original.