Engine overhaul?

[Goldie]

Hi everyone, Let me first say just how much I,ve learned off this forum from nothing more than reading through old threads, lots of great info here!

I bough a pretty decent 77 GL 1000 last February and have been cleaning here up for the past few weeks. It originally didn't have spark, and I didn't own a compression gauge at the time so I couldn't test the engine. after replacing the timing belts, and converting to electronic ignition I got it running last week.....well kind of. While running it was spewing a good amount oil out of the left side exhaust. Obviously this was a red flag for me! I went out bought a compression gauge and did a check. Sure enough compression in cylinder #4 was super low "85 PSI" the rest were all around 120.

My question is kind of just re assurance before I do a complete bottom end overhaul. There isn't a chance this is a top end problem right? oil coming out the exhaust and low compression in a cylinder strongly suggests at the very least the rings are bad???

Also any recommendations for the best place for parts?? rings, bearings gasket kit ect?


Here she is in her glorious before pic, cant wait to take the afters LOL

And a snapshot of her current state.

Any help would be appreciated, Thanks!!!

 

[dan filipi]

Oil wouldn't normally travel that far back.
Are you sure it isn't coolant washing the pipes of old carbon which could look like oil?

 

[Goldie]

Oil wouldn't normally travel that far back.
Are you sure it isn't coolant washing the pipes of old carbon which could look like oil?

It doesn't smell like coolant, and it has the consistency of old dirty oil.

 

[dan filipi]

Then I would say it's likely a broken oil ring.

 

[Goldie]

Then I would say it's likely a broken oil ring.

Oil ring? is that the same as a piston ring or something different.

 

[dan filipi]

At the top of the piston are the compression rings and at bottom is the oil ring.
All part of "the rings" as a package.

Spraying that much oil as you describe has me curios though. I would expect that plug could not even fire.
How do your plugs look?
One of them on that side should be wet with oil.

 

[joedrum]

okay this could all be in the exhaust valve ....obviously it has sat ....if it sat with this valve open a long time it could be coroaded up with old oil rust and water damage...its very possible the valve will tighten up along with the rings isay this is the cylinder that suffered the worst ....if its not making lowend noise ...and staying cool in tempiture id ride it some to see if it gets better the more it runs ...watch the temp too ...it could be blown head gasket too ....

 

[Goldie]

At the top of the piston are the compression rings and at bottom is the oil ring.
All part of "the rings" as a package.

Spraying that much oil as you describe has me curios though. I would expect that plug could not even fire.
How do your plugs look?
One of them on that side should be wet with oil.

Ok, thanks for explaining that. Yes the #4 plug is completely soaked in oil. it may not be firing "but it has spark out when tested out of the cylinder" i cant keep her running long enough to listen for a missing cylinder. I don't hear any knocking though.

It would be awesome if its a top end problem. I will have to remove the left head and inspect it before completely removing the engine.

 

[mcgovern61]

How long did the bike sit? Many times the rings will loosen with running. I would say that it is unlikely a bottom end problem.

 

[Goldie]

How long did the bike sit? Many times the rings will loosen with running. I would say that it is unlikely a bottom end problem.

It sat for at least ten years in a garage

 

[dan filipi]

The full history of this bike would help.

Often the rings will loosen and seat with run time, I've experienced that 2 times on 2 different engines.
That much oil though, hmm.

Maybe a flush with with atf in the oil would speed up freeing the rings.

 

[Goldie]

The full history of this bike would help.

Often the rings will loosen and seat with run time, I've experienced that 2 times on 2 different engines.
That much oil though, hmm.

Maybe a flush with with atf in the oil would speed up freeing the rings.

As far as a full history goes heres what I have " heresay from P.O."

Originally purchased by older gentlemen here in MI who rode it for about 20K

sold to his neighbor in late 90's early 2000's where it sat in his garage till 2010.

Given to his brother in law who rebuilt the carbs, realized it was too big a project for him and sold it to me.

That's all I know


Sounds like it would be worth trying to run it for a bit if I can get the carbs tuned half way decent

 

[dan filipi]

Get it running as best it can is what I would do then flush the engine and see from there.

 

[Goldie]

Get it running as best it can is what I would do then flush the engine and see from there.

I think that's what I will do, hopefully I get lucky! thanks.

 

[Steve83]

With only 20k miles, the bottom end should be like new. Just a thought - if it was on the side stand during storage, the left side cylinders might have taken some oil, which after all those years would leak past the rings. With an open exhaust valve, the header pipe and muffler would collect some of it. Either way, the more it runs, the better it should get - take Dan's advice with the oil/ATF flush.

120 PSI in three and 85 in one is low all around, but that's normal after sitting for a long time. It should come up after being run a while.

Also, is there lots of blue smoke from the left side, or just oil spitting out?

 

[Goldie]

With only 20k miles, the bottom end should be like new. Just a thought - if it was on the side stand during storage, the left side cylinders might have taken some oil, which after all those years would leak past the rings. With an open exhaust valve, the header pipe and muffler would collect some of it. Either way, the more it runs, the better it should get - take Dan's advice with the oil/ATF flush.

120 PSI in three and 85 in one is low all around, but that's normal after sitting for a long time. It should come up after being run a while.

Also, is there lots of blue smoke from the left side, or just oil spitting out?

I will definitely do the oil/ATF flush.


There is lots of blue smoke, and oil spitting out the left side.

 

[toytender01]

Sorry about the broken mufler, but you did a real good job with the cast :smilie_happy: :smilie_happy: :smilie_happy:

 

[Goldie]

Sorry about the broken mufler, but you did a real good job with the cast :smilie_happy: :smilie_happy: :smilie_happy:

Haha, yeah I may have gone a bit overboard with the heat wrap. Ya spend 50 bucks for a roll you really want to use it all!!

Here,s a photo of my first bike 72 cb750

I'm still in love with her and wanted to transfer some of the style I used with her to my new bike. Maybe I should just stick with the headers being wrapped again.

 

[mcgovern61]

If it sat that long and the PO claimed to rebuild the carbs, I would change the oil....there is a god chance that gas has leaked into the crankcase. I also agree that if it sat on its side oil (and potentially gas mixed in) would have leaked past the rings easily. Change the oil, clean the plugs and run for a while.

 

[Goldie]

If it sat that long and the PO claimed to rebuild the carbs, I would change the oil....there is a god chance that gas has leaked into the crankcase. I also agree that if it sat on its side oil (and potentially gas mixed in) would have leaked past the rings easily. Change the oil, clean the plugs and run for a while.

Yeah, that's a good call. The oil has already been changed once since I bought it. I will change it again add the atf for cleaning. then change it again with fresh oil.