Time to split the cases?

[Guest]

Hi there. Recently i pulled the head on my 79 gs750 to go through valves and clean it up, I put it back on and realized the motor was leaking from the base gasket, so i decided to pull the jugs off and do all new gaskets on the top end. However as i was cleaning up the jugs i found gravelly/grit in the jugs between the cylinders in what i believe are the oil galleys. I also found some grit in the chain area between 2 and 3 cylinders. S

So is it time to split the cases? I don't even know how gravel got into the oil, and it's been running fine as far as that goes. Can i split the cases and pull the crank without having to mess with the transmission? That's the part that scares me the most.

[Jedz123]

Curious... Did you pull out the oil filter? Did it look gritty? Is there one on there? Wouldn't be the first time I've seen a very old oil filter too loaded with grime, rip and let is contents go...

I would try to use some kerosene and compressed air through all the oil passages to clean out and derbies... Run a new filter and see how it goes... Very good possibility that this was dirt built up in the air fins that fell into the cases and passage ways when you took the cylinder block off the case... I wouldn't worry too greatly... I wouldn't split the case unless there is a major flaw... But it if runs well I'm guessing it's really no biggie.

My 2 Cents, I'm sure others may say differently. It's an old school Zook with a roller bearing crank...Very very hard to kill that thing.

[tkent02]

Gravel and rust gets stuck between the cylinders and the two center studs, it's open to the elements in there. It goes in the engine when you lift the cylinders, unless you know about it ahead of time and do something about it first.

[Sandy]

Don't use compressed air, it'll blow stuff around to who knows where. Also don't turn the crank yet. Pick out what you can with a bit of grease or some thing sticky on a stick or screwdriver then pull the oil pan and put a catch basin under the motor. Now get some mineral spirits, varsol or paint thinner and gradually flush the remaining debris into the catch basin, repeat until you're sure everything is out. Now you can spin the crank a bit and flush some more just to be sure there's nothing in the bearings. At this point if you're confident everything is out flush some oil through to displace any remaining solvent. If all looks good continue with the top end job, if not it has to come apart. On first startup run it until just warm so you can do a retorque and change the oil and filter.

[allojohn]

Drop the pan and see what's in the grime.