Topic: Oil spill

[icroof]

I have a '71 CB 750 that I bought about 7 years ago.  It is from what I can tell 100% stock just like it was purchased 40 years ago.  I had it running decently then but it sat for probably 6 years.  I have gone through and cleaned the carbs and tank. I changed the oil and it starts up pretty well.  The idle is not very stable (sometimes revving to 3k sometimes sitting at 950 - 1100).  When I rev the engine it is slow to return to idle (about two seconds).  Also, twice now after it ran for about 5 - 10 minutes it leaked a lot of oil out of the tube coming from the oil tank.  Any reason why it would do that?  Thanks for any help.
Ian

[Johnie]

Which tube from the oil tank? The big ones on the outside or the smaller tube that connects to the tranny from behind the tank? Oh, and welcome to the forum. How about a pic...we like pics here...

[icroof]

It is located at the top, back side of the oil tank and runs to the bottom of the bike emptying just in front of the rear tire.  There are two other hoses that are braided and one smaller rubber hose all of which run from the bottom of the oil tank to the engine / tranny.  This one is just rubber and runs from the top of the oil tank out.

Thanks for the welcome and I will get some pics up.

[Johnie]

That hose emptying just in front of the rear tire is a breather hose. Oil will come from that hose if you overfilled the oil. Keep in mind when these bikes sit oil will drain into the crankcase. Then guys will check the oil level when the motor is cold and it will look like it is low. They add oil and then it blows out the breather hose. Rule of thumb is to check the oil after the motor is warm. Did you by any chance add oil recently?

[tango911]

Also when the revs return slowly after you rev up and release the throttle, could be a sticky throttle cable,  if the throttle snaps back nice and quick then you prob need to sync the carbs and check out your plugs, might be running too lean?  just a thot or two.

[icroof]

Thanks for the thoughts.
I did add oil and apparently too much.  Except for the big oil spot in the driveway and the fact that the wife is going to kill me for it that makes me feel better.  Also I am pretty sure the carbs need to be sync'd. The plugs are new.  I have a lot to learn.
Thanks again.

[tango911]

just do a full tune up.  per the manual.  you'll be good to go.

[MCRider]

Thanks for the thoughts.
I did add oil and apparently too much.  Except for the big oil spot in the driveway and the fact that the wife is going to kill me for it that makes me feel better.  Also I am pretty sure the carbs need to be sync'd. The plugs are new.  I have a lot to learn.
Thanks again.

If the oil spot is truly an issue, try this. Get the bulk of the oil up with rags or whatever. Then pour some "OilDry" granules on it. Grind the oildry into the spot with a 10" or so piece of 2x4. Really grind it in until the oil dry turns to dust. Takes some elbow grease. The spot should be COMPLETELY gone. Just sweep the dust up and you're done. Works best on sealed concrete. If the crete wasn't sealed to begin with, you may not get the oil up completely.

[Johnie]

MC you are a man of knowledge and wealth... I will put that info in my head for future reference. Thanks

[willbird]

Another trick on the oil spot, go get some mineral spirits, or stoddard solvent......in today's EPA ridden world you probably have to do it at night on an evening with no moon, but dump the solvent on the stain, then soak it up with oil dry, repeat a couple times, good as new.

if you go to the farm store you can buy a large syringe, about 1" bore or bigger, with a bike you are not sure how much oil it has in it, add some, then crank it with the kill switch on til the oil light goes out and give it some time to get oil up top (fuel off) then turn fuel on, and fire the engine, and watch the tank, use the syringe to suck the extra oil out without an overflow.

[my78k]

Idle issue is likely airleaks on the engine side of the carbs. One way to know for sure is when it is running spray some wd40 or something around the boots. You will likely notice a sudden jump in revs. Even if the carbs look like they are seated correctly my guess is that they aren't...I'm guessing you're also getting a really loud clacking noise?

Dennis