Crankcase breather puking blowby, GS1000

[Twowheeledlife]

Hey everyone, I have a 1981 GS1000L that hasn't ran in quite some time. I got the bike to start and run, but when I rev the motor to a high RPM and it starts to decelerate there is a lot of very thin and gassy oil pouring from the crankcase breather hose. I suspect it to be the rings but plan to change the oil prior to pulling the top end apart. As always any advice is appreciated!

Cheers,
Pat

[Agemax]

you should do a cylinder leakage test or at least a compression test to see if it could be rings. are you sure the petcock is not leaking and over filling the oil level? this would cause it to blow through the breather if the level is to high.(and you say it smells of gas)

you may want to check out the petcock first. i would not change the oil yet until you have found the problem.(waste of new oil)

[Twowheeledlife]

Here's a link to the video of what I'm talking about

http://www.youtube.com/watch?v=e533ff0iwwk&feature=youtu.be

[Nessism]

Some blowby gasses are perfectly normal. Especially on an engine that sat for some time. You may be jumping the gun with a tear down. I'd check/adjust the valves and then put some good hard miles on the engine (several hundred if possible) before jumping to any conclusions.

[Twowheeledlife]

I tested the petcock initially to make sure of that issue. I had a faulty petcock on my 1977 GS550 so I'm a bit familiar with that one, but this one works properly

[AJ]

Compression is the first thing that comes to mind. Test it as is, and again with a squirt of light machine oil in each cylinder.

The gas smell could be if you're still using the enrichener circuit ("choke") to get the bike started. Exhaust will still smell like gas until it's fully warm, the pipes are hot AND you've run it down the road a bit. Otherwise you may just be smelling residual, highly rich exhaust that condensed inside the cold exhaust pipes when you started it.

Have you actually had this bike on the road, or is this just your first experience getting the engine running again?

How many miles are on the engine?

Sometimes light rust will build up on the piston rings and cylinder walls of engines that have sat a long time. Sometimes this will fix itself, sometimes it won't. IF the bike is actually running on the street, consider adding some Marvel Mystery Oil (MMO) to the gas as a "top end lubricant" for a tank. This will help clean and lubricate the cylinders. You might also consider a table spoon full of MMO poured into each spark plug hole and let it sit for a couple of days, turning the engine a little bit every day. The MMO will seep into your piston rings, dissolve any gunk in them, and possibly free them up if any of them are stuck.

[hjfisk]

Does the oil it pukes smell of gas? looks kind of thin in the video. How is the oil level. You didn't leave it on prime by mistake and fill the crank with gas did you?

[chef1366]

Your crankcase if full of gas.

[Agemax]

Does the oil it pukes smell of gas? looks kind of thin in the video. How is the oil level. You didn't leave it on prime by mistake and fill the crank with gas did you?

these subjects are covered in previous posts

[bbjumper]

Your crankcase if full of gas.

"DITTO"

[AJ]

I should have looked at the d@mn video before responding! LOL!

[chuck hahn]

Its full of gas for sure..petcock left on PRIme or its gone bad since he tested it. But in any case gas is flowing to the crankcase.