I have a 2001 gs500 and if memory serves me right 295 miles ago i topped the oil off and checked it. Now 2 days before my problem came up i checked it say at about 260ish miles and it is 3/4 full still which is just fine, i drive it to work and back the next 2 days then that night went drinking with a friend and left it chained in his front yard. next morning i wake up and got to get home to get clothes for work and it started raining sometime that night i go out start the bike and it fires up, i notice it back firing a little more then normal through the carb ( been doing this since i got it last owner didn't jet it right and haven't had time to learn how to rejet yet). The bike has no weird sounds once it is warmed up i start driving get about 3 blocks and have to keep on the gas to keep it alive at stops make it another 6 blocks in this time i notice when i start driving (might be m eyes playing tricks on me cause it only at low miles) that i see what i assume is smoke coming from the front of the engine left hand side. 1 block later i finally say there is something wrong here, pushed it to a gas station for cover from rain to look it over.

Now this is were i get super confused i dint see anything wrong with were the exhaust connects or anywere else so i go and check my oil it is at the Emark  . Now i am am like wtf i just checked it 30ish miles ago not that low i always carry some oil in my backpack so i top her up and fire her up, still doesn't want to stay alive with out my help but i see no smoke from exhaust while just revving it no weird sounds either. I end up walking the bike 2 miles to my friends apartment and leave her there while i go to work in my old wet soaking clothes later that night i head over check for oil leaks loose nuts/ bolts and find nothing so me and friend decide to fire her up. she just purrs to life nothing weird we notice some WHITE smoke for the first 2 min or 3 but it has no smell to it and it just leaves the hand like a highschool boy who is nervous as f%$k about asking out some girl.

We rev her up and down for 10 maybe 15 mins checking for oil leaks and smelling the exhaust for the terrible oil smell...NOTHING. Now i have a cobra FR1 exhaust on it and it sits at a really stupid angle were i thinking rain water got in there and caused the keeping her alive at stops and all the backfiring at the beginning and after sitting in a garage for a day and the some driving i did she dried out but i still cant get to were my oil went because there is no smell/leak and if i went through 3/4 of the stick from F to E in 30ish miles i would think there would be a lot of smoke and strong smell coming from my bike. Now the friends house that i stayed at was on the worse part of town and he thinks someone might have f%&ked with my bike at night cause they saw i had it chained. I will be riding some tomorrow 15 miles then checking for most the day and report back on my finds but i am at a really confused state right now. If anyone can help me that would be amazing.

Now before you ask yes i waiting 5 to 10 mins before checking oil level and yes always on flat ground with it on the center stand.

Vapor/bubble lock somewhere up in the oil galleries when you check and was low? .. maybe? ...

You had a stuck open exhaust valve, wonky  piston rings and spewed oil out in a short distance..  bike cooled, valve returned to normal. ... maybe?

.. hang on. . 260 miles and it was down to 3/4 mark? ... ok I know these bikes use oil.... a bit! ... and that each bike according to age and use will vary.

But while I haven't ridden mine in 6 months... I remember adding oil maybe every 1500km?  . Whatever that is in miles... your usage seems excessive to me at least?!

so 1500km is 933 miles give or take 1 mile and that is what my bike did tell this problem rose up. not super smart on mechanical things but i did just check my exhaust shims and they were right were the book tells them to be at. So could be reading that exhaust valve part wrong, any way to know if piston rings are "wonky".

I can't imagine why somebody would drain your oil just because it's chained up.... but people do amaze me.

When you checked it when it was full, did you screw the dipstick in or just lower it in? That's all I can think of...

just let the dip stick rest right on it no screwing what so ever. Yeah i understand the why would someone mess with it thing also but i am running out of ideals and the friend brought it up due to the fact that 2 weeks ago some guy slashed close to 30 car tires for no reason. Just hoping for the best preparing for the worst.

To drain the oil from your bike seems a bit sophisticated to me, for someone to do just for the lulz.

I will have you know that i have had to refill my oil yesterday (nothing on the dipstick, seated in place, not screwed) This while 100 miles ago i checked my oil, and it was at full. So you're not the only one :p

Im going to investigate my problem, and ill be checking regularely for leaks, oil level etc. If i find anything, ill let you know.

Yeah me to man keep in touch hoping it was just a fluke to a the day and ride

Just finish riding 200 miles and not a drop missing from her now even more confused what happened to the oil a couple days ago

When the oil went missing.. Had you been riding it hard/very hard/like you stole it? 

no i have not i never have ridden my bikes hard like i stole them. The day it went missing though i do remember the bike didn't want to push up to 80mph to well once i hit 70-75 range, but that went away on its own.

My gs burns some oil, maybe a quart per 3k miles. I would think a loss like that would be noticeable. Tell me, is your chain very oily? Old yamaha twins used to leak from the clutch pushrod seal, and it could be hard to notice, other than the mysterious feature of a self oiling chain. If you are mechanically inclined, pull off the front sprocket cover and look for a lot of oil buildup around the clutch rod or behind the sprocket itself. I dont think its common for the gs, but rubber is rubber, and it gets old and hard over time.

Quote from: i8ball on May 20, 2015, 08:58:59 PM
no i have not i never have ridden my bikes hard like i stole them. The day it went missing though i do remember the bike didn't want to push up to 80mph to well once i hit 70-75 range, but that went away on its own.

That's the point where the bike burns oil and fuel economy goes down....near 7K rpm and above.

Driven it many times at that speed with no problems ever. Still that much oil in 20 wish miles is a lot

mine also doesn't lose oil. I've never had to refill it. Usually I fill it up to the 'full' line, and change it at 3k miles being more than half full (on the dipstick).

.... yep... the dipstick! ...

Confusing things sometimes. .. you gotta handle them right or they give you false info!

Quote from: MeeLee on May 31, 2015, 04:27:46 PM
mine also doesn't lose oil. I've never had to refill it. Usually I fill it up to the 'full' line, and change it at 3k miles being more than half full (on the dipstick).

Hard to believe unless you have low mileage or never do prolonged highway speeds over 65mph

Slippery little things those dipsticks! !!