Topic: 'Oil Stop Leak' in a motorcycle engine

[newcomtd]

I just put fresh oil in my 1975 CB550-F and started it up for the first time in four months today.  It runs great and I went for the first ride of the season and everything seemed to be great.  I ran it through all the gears and got up pretty high in the rpm range when I took it 95mph.  I though all was fine but when I got back I noticed some drops on the ground and oil on my center stand.  The bike has only 5,500 original miles on is in excellent condition and has never leaked before.  One spot is the shifter seal which I can easily replace.  However, there is another leak higher up that I cannot see and I was wondering if some kind of 'Oil Stop Leak' product is suitable for motorcycle engines/transmissions.  I have used it in cars before and it works great but I am thinking that is probaly isn't a good idea to use in a motorcycle.  Any thoughts, experiences, comments?  Also, is there any real difference between motorcycle specific oil and car oil?

Thanks

[Terry in Australia]

There are probably several archived threads on this subject mate, I've used oil stop leak on CB750 engines with limited success, it shouldn't hurt your engine by adding some "oil thickener" as it'll stay on your cam, rockers etc to reduce wear on start-up and reduce engine and transmission noise, but remember that the oilways on our bikes are tiny, and while it's doubtful that an oil thickener will actually block an oilway, it may reduce the oil flow when cold. Bike specific oils tend not to contain "friction modifiers" which will make your clutch slip in a wet clutch setup, common to our bikes. Cheers, Terry.

[Phaedrus]

I tried that stuff in my scoot and it made no difference.  Nothing seemed to be affected mechanically, but it did not stop the leak.  My leak could be worse than yours though.  I got a 605 kit and gasket kit comming and that will take care of it though.

[bryanj]

On the 550 there are only 3 possible (probable) leaks inside that case:-
(1) Shifter seal---easy fix seal still available
(2) Oil pump cover "O" ring--"O" ring not available from Honda but I have some kits i made up
(3) Oil pressure switch--still available but pricey

I NEVER had an undamaged sprocket seal leak.

[crazypj]

What oil did you use and did you warm up engine before revving it? The oil pressure switch is screwde into the top of pump on 550. It opens at 4psi, I blew the tops off a bunch under warranty until I found out what I was doing wrong (being 19!!!, damn, thats 30yrs ago)

[clarkjh]

What oil did you use and did you warm up engine before revving it? The oil pressure switch is screwde into the top of pump on 550. It opens at 4psi, I blew the tops off a bunch under warranty until I found out what I was doing wrong (being 19!!!, damn, thats 30yrs ago)

So.........
what were you doing wrong, I don't want to pop the top off mine.

James

[crazypj]

getting motor over 7,000 rpm before warm up (hell if your going to wear it out, do it under warranty!)
And yes , I did get an engine rebuild before the year was out. Took things a bit more gently when I had to pay for it, made sure it was hot before I revved the hell out of it then did a 591 homebrew kit at 30,00miles (was working for the dealer I bought it from by this time)
PJ