oil in airbox after 80mph+ for 150 miles

[tconroy]

I did a search but did not come up with anything.First of all the bike ran great like always.Went 600 plus miles saturday.This was mostly 60 to 85 mph.all day long.When i parked it and checked later I had about a quarter size puddle that came out of the airbox drain tube.If i ride all day long and stay under 60 this does not happen.The bike never uses oil in between changes either.I had to add 4 ounces of oil also which I would say was probably what came out of the airbox.My bike always runs great and never leaves a puddle till i go down the highway for a long period of time at a high rate of speed.The oil doesnt bother me and this does have ahigh oil pressure since it's a 650 L model and has sleeve bearings.I have never pulled the valve cover off but I here there is a filter above the cam cover that is suppose to stop the oil from going down the crankcase vent tube and into the airbox,is this right?? Any input would be helpful.I just don't know if it is something to be concerned about.

[t3rmin]

Do you have an oil-type air filter?

[tconroy]

Do you have an oil-type air filter?

Yes I do but I have made sure not to overdo the oil on the air filter.I have had this bike for 3 years now and always take care of it to the book.

[TheRedlineMan]

You're blowing overheated oil through the engine breather pipe, which attaches to the airbox. Rings are probably showing some wear as well, which is only showing up under prolonged harder than normal riding

If you're going to maintain those sort of speeds/duration then think about putting on a small oil cooler.

You're right about the filter, but it's more like scrunched up chicken wire than an oil filter material, and can only deal with so much oil mist.

[tconroy]

You're blowing overheated oil through the engine breather pipe, which attaches to the airbox. Rings are probably showing some wear as well, which is only showing up under prolonged harder than normal riding

If you're going to maintain those sort of speeds/duration then think about putting on a small oil cooler.

You're right about the filter, but it's more like scrunched up chicken wire than an oil filter material, and can only deal with so much oil mist.

I have 31750 miles on it now and I will do a valve adjustment soon when winter hits.It is possible that it is missing the scrunched up chicken wire and I also make sure it is at the full level before going on a long trip.I dont burn or use oil otherwise.The bike runs cool and doesnt "tick" or anything after turning off.If I run the oil a little lower in the glass,say about half to 3/4 it does not do this.The plugs have excellent reading and are perfect in all 4 cylinders.I have also read on another sight that this little bit is normal. Would valves have anything to do with this?Getting back to the chicken wire thing,Im almost certain that this has been removed in the past for some reason, but why????

[TheRedlineMan]

PO probably didn't understand the importance of it (the filter that is), and you will end up with more oil ending up in the airbox without it. The reason that they use such material is that it doesn't restrict the flow of air, while 'collecting' a lot of the misted oil. It also doesn't require regular replacing like a normal oil filter.

Running an air-cooled 650cc bike all day long at those speeds will get the motor hot, not necessarily over heat it, but it will be hot. Even 1100's will run reasonably hot under those conditions.

The rings can show wear, and at the mileage on yours they will definitely be showing signs of wear, without it being a significant problem, replacing the filter material could well sort out the problem. An oil cooler isn't necessary but it will prolong the life of the motor if you are planning many such rides.

Be careful about running low oil levels on GS's, the stator runs in an oil bath and will rapidly deteriorate if there is insufficient oil.

[tconroy]

PO probably didn't understand the importance of it (the filter that is), and you will end up with more oil ending up in the airbox without it. The reason that they use such material is that it doesn't restrict the flow of air, while 'collecting' a lot of the misted oil. It also doesn't require regular replacing like a normal oil filter.

Running an air-cooled 650cc bike all day long at those speeds will get the motor hot, not necessarily over heat it, but it will be hot. Even 1100's will run reasonably hot under those conditions.

The rings can show wear, and at the mileage on yours they will definitely be showing signs of wear, without it being a significant problem, replacing the filter material could well sort out the problem. An oil cooler isn't necessary but it will prolong the life of the motor if you are planning many such rides.

Be careful about running low oil levels on GS's, the stator runs in an oil bath and will rapidly deteriorate if there is insufficient oil.

That's why i keep it to the full mark cause I just put in a new stator 3 months ago.I would rahter have the oil in the airbox than a fried stator.I only run it like that when I go on long trips down the highway.Maybe I should just stick with the posted speed limit, ya think??LOL!!! I will be taking it apart for a valve clearance check and then find out whats really in there.I do change the oil every 1500 miles and filter every other and use genuine Suzuki 10w40.

[Greg O.]

I realize this is an old post, but I want to share what I just learned on my bike. My 1979 750 has been dripping small amounts of oil from the airbox since I have owned it. Not enough to call it oil consumption. I add about a pint between oil changes. But is just enough to make a small mess. Well when I removed the valve cover two weeks ago to check valve clearance, I was cleaning the cover. I removed the screens in the cover, and noticed there are two small drain holes under the screens, to drain excess oil. Both of them were plugged. Last summer I took a long piece of hose and made a loop out of it and replaced the straight crankcase breather hose. Seemed to make some differance. I am hoping cleaning the holes under the screen in the cover will make a differance by allowing more oil to drain back towards the oil pan. My thinking is that oil pooled at the point where the crankcase vapors pass is more likely to be picked up and blown out, especially at high speeds. Has anyone else here seen these small holes plugged?

Greg O

[tconroy]

I just did a valve adjustment and did not have the screens at all!!!! I got some new ones and put them in ...problem solved!!!

[Greg O.]

tconroy,

Did you happen to notice if 2 holes under the screens were open?

Greg O

[tconroy]

tconroy,

Did you happen to notice if 2 holes under the screens were open?

Greg O

Yes the holes were open but no screens were in place. I have not had a problem since replacing the screens.

[BassCliff]

Breathing right

Mr. tconroy,

I'm glad you found the wire mesh for the breather. For those of you who have never had your breather or valve cover off, here's what it looks like (at least on my bike).



This information is included in the valve adjustment pictorial guide at my little BikeCliff website. Please feel free to drop by and take what you want. It's all free for the downloading, guides, manuals, wiring diagrams.

Thank you for your indulgence,

BassCliff