I ran her low on oil

[Anonymous]

I can't believe this has happened but when I was parking my bike I had the low oil light come on!! In the end it took a whole litre of oil to get my bike topped up and I'm wondering how much damage, if any, I have done. For the last two days I've had trouble idling but it isn't an indication of the engine seizing as I topped the bike up and it is okay now.

The reason I figure this happened is that I had a total break-down of the oil in my bike. After changing the bikes oil and filter I put 1400km on the bike in one trip with no problem and then let the bike sit for a month. After the month of sitting I checked the oil and headed out on another 600km trip and thought nothing on checking the oil since I did so well after the previous trip but one week later here I am down 1 litre and it isn't from a leak. Is this a normal phenomenom? I had the same sort of trouble with burning oil before the previously mentioned oil change but I didn't expect it to resurface again as I am using a different brand of oil and I have been in the mountains since.

Any ideas on the two concerns? Thanks, Steve

[Jethro]

If you have no leaks you must be burning oil. There's no coolant resevoir for oil to leak into so it's gotta be burning out the exhaust. Have someone (or do yourself) a compression test of the cylinders. Burning oil on these old air cooled beauties most likely means you need to hone the barrels and replace the rings. You may need to perform a leak down test if the wear is minimal. If you lost that much oil in 600k, then I would think you would see quite a lot of white smoke out the exhaust. Notice any smoke? Any loss in performance or fuel economy? If it is stalling out when warm than oil could be seeping past the rings and into the cylinders. When you blip the throttle, you regain stability because you have burned out the seeping oil. Have you any leaks (even slight) at the head gasket? Have you recently tourqed the head down? When was your last valve adjustment?

[Anonymous]

Hi Jethro,
I agree with you that the oil is burning out the exhaust but I haven't figured out why exactly. As for smoke? I dunno, I'll have to rev her up tomorrow when she's warm to see if I can get any oil to puff out the exhaust because I don't see any when I start her up in the morning. This weekend I'll pull the plugs and have a look at them as well as do a compression test just in case.

As for maintenance, I set the valves when I changed the oil so it isn't due yet. I could probably torque down the head if I can find a decent wrench but is it necessary? The bike has 26,000km on it. No doubt all of them have been abusive though. :roll: I can't believe I'm the bikes 8th owner and it is still running.

Oh yeah, did you mean hone (remove metal) the cylinders or just re-cross hatch them? I guess it depends on the condition of the jugs...but pistons aren't available any more from what I've been told.

Steve

[saaz]

Not getting oil smoke when starting does not mean you don't have ring related oil consumption problems (my 78 gs1000 can smoke on starting due to oil guide seals being a bit old). Under load is probbaly where it is using oil. Before I rebuilt mine it used to smoke going up hills under load. I could be that the bike was not run in properly and has glazed the bores. hard to tell without a compression test and engine pull down.

[Anonymous]

If you intend on removing metal from your cylinder walls that is best handled at a machine shop. They have grinders that are dedicated for that purpose. To deglaze buy a piston hone tool and run that sucker at LOW speed (40 to 60 RPMs) to deglaze and get your crosshatch set. AS far as pistons not being available for your bike, that can be cured with a little imagination. There is probably something out there that is really close and that with a little machining can be made to work. The big thing to watch for when matching pistons to a block is the diameter of the bore, the shoulder depth of the piston and the distance from the center of your wrist pin to the surface of the piston. If you can find something that is very close and slightly oversized (.025 to .050 over) it would be a piece of cake to have it sized to match the bore. You would have to cut the ring grooves to the correct depth and make sure the shoulder was trimmed (if neccessary) so it wouldn't bounce off your connecting rods. If the depth of the piston from the wrist pin to the surface was within .050 you could probably run it with no problems. Being shorter than the stock piston isn't ideal but will still work, but longer.......you'll have to buy a slighly shorter spark plug or shim out your plugs to keep them from hitting the piston at TDC (top dead center). As far as rings go, they are manufactured in every conceivable diameter and be bought oversized or undersized to match the diameter of your bore. Good luck with your project.

[robinjo]

I wonder if a GS500E engine (the 2 cilinder one) would fit, I had a '81 GS450 and a '92 GS500 and compared the engines, they look very similar to me and you can find them quite easily.

[Anonymous]

I just remembered something! Ofcourse it just make me look like a bigger fool but I put in a tank of, uh, Ethanol, before this all happened. The confusing part about Canadian ethanol is that it can have less Ethanol content than regular gasoline so I decided to put it in as it was the highest octane fuel available at the station. Maybe I have ruined my rings since this stuff could have washed off my cylinder walls. I got worse mileage with it as well. Any Canadians have any comments of the Ethanol(green pumps) in Ontario?

Steve