Where is my oil going?

[Macmatic]

I've got about 300 miles on the GS750 now and in that time I had to add two quarts of oil! The first was at around 100 miles and I thought I'd found the reason (and a reason to be thankful things didn't get bad fast) when I found the drain plug finger tight from when I installed the engine and took it out to clear the frame. I assumed my oil loss would stop for the most part...


100 mi later I needed another quart.

Now another 100mi later the level seems to be OK. This is the first time the engine has been run in around 10 years so maybe rings/seals and things needed to reseat but once I noticed the oil dropping I kept a close eye on the engine for leaks and tried to watch for smoke out the back.

I checked in the mirrors myself for smoke and didn't see any under hard acceleration or after coasting down in gear (to suck oil past the valve stem seals) and then opening it up.

I also repeated this with a "chase car" watching me and still no signs of smoke. The pipes have a little carbon build up in the ends but not much....I mean its an internal combustion engine after all! I can wipe a finger in the pipe and see the carbon on my finger but still see my print too.

I guess I won't worry about it if it doesn't drop in the future but any thoughts on why it would have been dropping and then stop?

/\/\ac

[Guest]

Hi Mac, My GS 1000 seems to use a quart in about 800 to 1000 miles. Also have no smoke or drips although the right exhaust is a little oily. I'm undecided about pulling the cylinder this winter as it seems to be running fine. I'm thinking this is just the nature of the beast, but still don't like it. What are you other guys seeing for oil comsumption? I don't want to waste the money for gaskets etc. if this is normal. Ray

[shortlid]

Normal if not run for awhile

Macmatic, I would not worry about it. I bougt my '80 GS850 out of a junk yard for $275 it had sat for 2 YEARS in the junk yard and who knows how long before that!

When I first got her running she used about a qt. every 300 miles on highway trips. It stoped using that much oil around 1000 miles after I got it. Now it uses about a qt. every 1,000 miles and I think that is OK for a AIRCOOLED motor that is 25 years old with 37k on it. When I do get on it it does blow VERY LIGHT blue smoke though.

[focus frenzy]

with these air cooled engines oil consumption can and does vary widely dependent on multiple conditions.

engine temperature being the biggest factor on oil consumption, the hotter the engine the more oil it will use, get into allot of stop and go traffic and the engine will get hot and use more oil.

ambient temperature ties into engine temp, the hotter it is outside the more likely the engine will get hot.

how hard you run the engine also effects oil consumption.

my bike can suck down oil pretty fast in the heat of summer here if I get caught in bumper to bumper traffic, yet during the cooler months on long rides it will almost not use any oil at all.
I currently have better than 45,000 miles on the top end overhaul.

[rustybronco]

the aeromatics in motor oil burn off, with mine using quaker state 10w40 lost about 10-15% when using rotella-t 15w40 nada....
just a thought http://motorcycleinfo.calsci.com/Oils1.html
p.s. and volatility

[cloudbreakmd]

Are you running the stock airbox?

[Macmatic]

Are you running the stock airbox?

Yep. Stock airbox and foam filter. Getting 42-48mpg so far too. the 42mpg tank was about 1/3 70mph highway riding.

I just put on another 100mi in the rain and the oil level is still the same...maybe it was the lighter parts of the oil burning off...

Thanks for the input and ideas everyone!
/\/\ac

[Buffalo Breath]

oil

when you have a motor that has been sitting in various positions all the nooks and crevesis as well as the top end drain off so even if you filled it up on the site glass, after running it the oil finds those dry spots an stays there so after a ride the oil is down, also the clutch will go dry from sitting, and after running will soak up some oil

[tfb]

I've had two GS Suzukis (a GS1000S and now a GSX1100 Katana) and when I got them they were both chronic oil-burners. OPEC sponsorship was looking like an attractive option.

But after a fresh set of rings, honing the cylinder bores, and a new set of valve seals, each bike barely burnt a drop between oil changes (3000km = 1864 miles) -- there was no visible change in the oil level at the sight-glass. And both engines remained in this happy state for years.

So IMHO, burning oil is not acceptable, and it means something has worn out. Of course, topping the motor up with oil is waaaay cheaper than a top-end rebuild, and unless your compression is so low that she won't start, or burnt oil is fouling the plugs, there's no harm in continuing as you are.

Mike.

[KGB]

tfb is on the right track.

My 1000S sat for about 5 years before I rescued it 16 years ago....

The valve guides were dried out. Oil was weeping past them under hard throttle.
This turned from a simple valve job, top end, to a complete motor rebuild 10 years ago.

Just a warning, be prepared. I have a very good mechanic, that is amazing with a boring machine. We went from doing a top end, to
"wel lthe center 2 cylinders are out of round, "OK bore it" to
replacing everything except the crank,rods and cams.


Was it worth it? Of course, the bike, 10 years later still runs strong.
My point. long winded, is be prepared. Once you open up that motor
one thing will lead to another.
Vunny, the mechanic, smiles everytime he sees my bike.

Oh and it doesn't use very much oil, about 1qt every 1000-1200 miles
depending on how hard it's ridden.