Blowing Oil after long high speed runs.

[Redneck]

Okay a few of you might know that I attempted to make it down to skateguy's charity run he put together. Well, my lack of gear and the cold temperatures turned me around. (in hind sight a good thing) I had gone down about 58 miles, all interstate before I stopped at McD's to warm up and head back home once I could feel my fingers. It was as I turned onto the road in front of my house that I noticed my left boot was covered in oil. I got home put the bike on the center stand and found that she was a little over a quart low on oil. I left the bike alone for the next three days but noticed no more leaking oil. I have ridden it back and forth to work for a week and a half and have not been leaking any significant amounts of oil. So my question is this. Could the prolonged ride on the interstate, running the engine at high RPM, I was running about 70-75 mph on the interstate, have created enough pressure in the crankcase to blow the oil out the base seal? I do have a small seepage leak on the base gasket but it has never spewed oil out. Inquiring minds want to know. Thanks in advance.

Paul

[drejal]

valve cover gasket?

a couple of the bolts in mine had vibrated their way loose, I came home with the same oily shin as you. are any of the cooling fins on the cylinders oily?

[Graham]

Okay a few of you might know that I attempted to make it down to skateguy's charity run he put together. Well, my lack of gear and the cold temperatures turned me around. (in hind sight a good thing) I had gone down about 58 miles, all interstate before I stopped at McD's to warm up and head back home once I could feel my fingers. It was as I turned onto the road in front of my house that I noticed my left boot was covered in oil. I got home put the bike on the center stand and found that she was a little over a quart low on oil. I left the bike alone for the next three days but noticed no more leaking oil. I have ridden it back and forth to work for a week and a half and have not been leaking any significant amounts of oil. So my question is this. Could the prolonged ride on the interstate, running the engine at high RPM, I was running about 70-75 mph on the interstate, have created enough pressure in the crankcase to blow the oil out the base seal? I do have a small seepage leak on the base gasket but it has never spewed oil out. Inquiring minds want to know. Thanks in advance.

Paul

Hmm, 31 year old motorcycle plus high RPM on a cold day? Yes!

[Carter Turk]

Check the crankcase breather hose to the airbox. When 2 pistons chunked between the rings on my 750 ET, the airbox behind the carbs was full of oil. The starter motor cavity, and the very bottom of the stator cover might be a place to look also.

[tkent02]

Could the prolonged ride on the interstate, running the engine at high RPM, I was running about 70-75 mph on the interstate, have created enough pressure in the crankcase to blow the oil out the base seal?

No, a 550 in good shape can spin high RPM forever with no problems. If it leaks, there is a leak to fix, plain and simple. If pressure is building up in the crank case, fix the breather too. The leak will only get worse. I would suggest going on such a ride, when it starts to leak, clean the oil off the engine immediately, (maybe pull in at one of those coin op self spray car washes) then blast down the highway a mile. You should be able to see where it is leaking. Maybe use some powder to help spot the leak.

[49er]

Check your crankcase breather where it enters the airbox. If the 550's are metal boxes like the early 850's are, there is a thin flat tract inside the top of the airbox that rusts and closes off, causing pressure build up in the crankcase. When this happens, any old gasket surfaces usually leak oil. Base gaskets, cam chain tensioners and speedo drives are all areas that can be afflicted with leaks.

As tkent02 has pointed out, you'll still need to fix the leak.

[mlinder]

Also check inside your starter enclosure.

We had an issue on a friends GS750, the seal for the stator cable which passes through the it had gone bad.

Took us a while to figure out wtf.

[cyclefvr2]

id say check the head,and valve cover ,and timing tensioner, well check all the bolts, mine had a lot that vibrated loose, mine was leaking oil on the right, at high rpm's it was the valve cover, and 1 small head bolt not the main head bolts
dosesnt hurt to check everything though

[almarconi]

The leak could be in the head,running down and leaking on your boot. Leak may not be evident at low RPM's. I had a KZ 550 with a cracked cam journal that would leak after a spirited run on the highway but was fine around town. I would remove the valve cover and have a look. Washing the engine and then using powder as Tom suggested is a good idea.

[Redneck]

Thanks a lot for all your suggestions. I will definitely check and see if the breather is good. Another question is there suppose to be oil in the stator cover? I took it off a couple weeks ago to check the wiring because I am having a charging issue, and found a lot of oil inside the cover? I need to break out the stator papers and go through everything, to find the problem with the charging, maybe this weekend, for now I have the kickstarter.

[cowboyup3371]

Yea, everything I read says the oil helps keep the stator cool. But I'm no expert either.

[tas850g]

Yes oil should be in there to help cool the stator.