How to find and fix an oil leak on a Yamaha scooter

Question

Some months after I had my scooter serviced I noticed oil splotches under my bike everytime I left if for a while in the one spot. The company that serviced the bike did numerous things wrong including getting a cable stuck in the throttle assembly (since been fixed). So I suspect that something they did during the service has caused the oil leak. The whole bottom of the engine is now coated in oil.

Have a look: http://memecode.com/temp/scooter/index.html

Said company won't obviously take responsibility for the leak and I'm a little short on cash, on top of that all the reputable companies in the area have waiting lists longer than a month.

So I'm up for attempting to fix it myself. The scooter is not worth a whole lot anymore, so I don't have that much to lose :-|

I heard from a friend that there is some sort of seal that has to be applied when the oil change is done? And if it's not changed you can get a slow leak like this? I've removed a lot of the panels so I can access the bike, but I can't see enough to know where the leak is.

Help?

Update: The engine has been degreased and the leak is between the cylinder block and the crank case. And that seems like it's just too hard for me to attempt at this point. And probably too expensive to pay someone else to do as well. I might have to put up with just filling it up with oil in the meantime.

Answer 1

First thing you should do is get the engine nice and clean using some good quality degreaser, a brush and a hose to wash it down, this will make identifying the leak much easier.

After everything is nice and clean take the scooter for a 10 minute ride, then have a another look. This time it should be much easier identifying the source of the leak.

Most likely your friend meant the sealing washer on the sump plug. This should be replaced whenever the oil is changed to ensure a good seal. I would also check to make sure the sump plug and the oil filter have been tightened correctly. Either of these could be the source of your leak.

While your at it you might want to add some oil to your engine. By the looks of those photos it's leaking quite a bit of oil.

Answer 2

That kind of leak can be quickly fixed with gasket silicone (which is VERY cheap and great stuff, I use it everywhere because its easy to use, tolerates high temperatures and seals oil better than the regular gaskets! You can use it together with the regular gaskets to get a seal that last for life!

However in your case it would be a temporary fix, if you just put the silicone on top of the leak (after of course cleaning the surrounding area thoroughly with e.g alcohol), but its better to have a temporary fix than nothing. Just make sure you use enough silicone and that the silicone sticks to the engine all around the leaking area.

I realize your question was posted a year ago, however for future problems with leaks and bad seals, this should help a lot both you and others viewing this thread as its a common problem.

Answer 3

Use a oil die to find your leak http://www.truckpartsandservice.com/tracer-introduces-oil-leak-detector/ to fix your leak buy a new gasket / seal or repair the existing one with Oil Resistant silicon.

Answer 4

This is not a serious issue as long you keep from riding your bike in the same condition. Every bike has oil seals. Your friend is rite. To avoid leaking of the oil from the crank case, we have oil seals. Changing a set of oil seals wont cause you much. I don't have much details on how to get it done, but i know it requires a mechanic. Its a cheap and simple process for a mechanic. But first clean the engine properly and add new fresh oil. That should fix the problem. I own two bikes and changing the oil seals in both the bikes never took more than a day.