Oil very black

[Potts4]

Hey all,

I have been working on a 1979 GS1000E that was given to me as a gift. It was far from running as it was missing lots of parts. I found all the parts from various locations, web sites, friends and with the use of this forum got it on the road and it has been running well all summer and I'm having a ball with it. So this was my first total overhaul of a bike so go easy on me. I'm planning on changing the piston rings this winter because the oil was turning jet black very quickly. Is this the right thing to do, or is there something else I should be changing? The pistons are in good shape and the sleeves don't seem to have any defects that I can see. Oh ya... compression was about 110-130 which is kind of low.

[Nessism]

If the engine is already apart, yes, change the rings. Personally, I wouldn't pull down and engine just because the oil was turning black. I'd check compression and let that be the judge of the rings condition.

when changing rings the cylinder should be bottle-brush honed with a 320 grit hone (240 grit will work also). And assemble with OE gaskets, not aftermarket unless you want to gamble on a leak.

Good luck

[Pendulum]

Have you done a compression or leak down test? Start there if you're concerned with condition of rings and/or valves.

[Potts4]

Sorry, you guys are to quick. I edited my message to include that the compression test reviled 110-130 psi depending on the cylinder. Valve stem seals have been replaced before I put it on the road.

[Potts4]

Is 32.99 to much for a set of rings? Of course I will buy 4 sets....

[5azzmonkey]

Was it dirty from the first oil change or is it happening on all of them? I know my oil (bike was sitting 10 years) was black in less than 100 miles from cleaning up the nice film of sludge that formed when the bike sat for 10 years.

-Dave

[SVSooke]

Drop the bottom pan and see if you have sludge built up on it.My 81GS650E would do the same thing till I cleaned that.

[Potts4]

Engine oil pan was clean, and this has happened on every oil change. I have been using the same oil every time, maybe its time for a change. If I were to buy new piston rings would you recommend OEM or OS 0.5 or OS 1.0??

[GateKeeper]

What do you mean same oil, the same brand and viscosity, or your draining the oil, and reusing it, boy I hope not, and I am just misreading, what you wrote

[DanTheMan]

Bad rings won't cause black oil. They'll cause oil smoke from the exhaust and excessive oil usage, loss of power as well. Good detergent oil and dirty innards will cause black oil. If you're not using oil excessively, and otherwise the bike is running well, it's a lot of trouble to get into for something that doesn't need fixing.
Remember, the tranny runs in that oil too, so there are a lot of places for the oil be cleaning dirt out.

[SqDancerLynn1]

I think you are over thinking the problem. If it is running fine? just ride it. If the motor had a sludge buildup internal it may take 4-5 oil changes to clean it out if at all. WHat type of oil are you using ?

[Potts4]

I had the engine completely apart before it was running and you could eat off of the internal parts and casing. I'm using Castrol 10W-40 and yes it's brand new oil everytime hahaha

[DanTheMan]

I had the engine completely apart before it was running and you could eat off of the internal parts and casing. I'm using Castrol 10W-40 and yes it's brand new oil everytime hahaha

You had it torn all the way down and didn't do the rings? If I have an engine apart that far rings get done, then I don't have to worry about them. How many miles have you put on it since reassembly?

[hjfisk]

I've used caster oil in the past and noticed the same thing that the oil seems to get dark or blacker then other oils. I would switch oils try the Shell Rotella T oil. I would not tear the motor down for black oil unless you have oil smoke. Also these old work horses we love so much will burn a little oil when they get heated up . My Gs 1000 G will use about 1/2 qt every 1500 miles

[BassCliff]

Greetings and Salutations!!

Hi Mr. Potts4,

Let me dump a TON of information on you and share some GS lovin'.

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Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

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Thank you for your indulgence,

BassCliff