Oil leak mess! By nalrac (Read 6,651 times)

[nalrac]

Hey Guys,

Here's (hopefully) the final mystery to solve on my scoot.

As I've mentioned before, I have an oil leak and boy is it a mess! Oil is getting everywhere. It was just plain impossible to see where it was coming from so I took the suggestion to strip ever bit of plastic and degrease the entire thing. Then, I let it run for about 20 minutes and noticed an oil seepage at the bottom of the right crankcase cover, near the bottom of the filler spout. Oil was also seeping from between the right crankcase and crankcase cover in front of the back wheel, inside the wheel well.

So, I tightened the bolts on the cover and cleaned again. I ran it for a while and didn't see a leak so I hoped that it had stopped it. However, this morning I reassembled the whole thing (ugh) and within two miles had another oily mess under the engine. So, here are my questions:

1. Can oil from the right crankcase get all the way up to the front of the engine area? I imagine that the wheel turning and the airflow inside the engine area can make a big mess. It's even getting under the plastic shroud over the engine. Could the flywheel be slinging it around?

2. What do I need to know about removing the right crankcase cover?

Thanks in advance!

- Adam

[sprocket]

yes.. the cooling fan actually whips an oil leak all over the engine...sounds like you have gaskets failing...

How much oil do you have in the engine? Is your valve cover vent tube clear and open?

[nalrac]

That's what I thought would happen.

The oil is right at the middle of the dip stick. The vent tube seems to be clear and free. I'll take it off and double check though.

[sprocket]

I have fixed engine oil leaks from the outside by cleaning the seams with acetone or something similar and the running a bead of clear silicone down the seam, pushing it into the seam as you go. Let it cure for a day...

Some engines are probably 4 years old and not a leak...

If you are using synthetic oil.. go back to dino oil.. synthetics are known to leak along case seams in these engines...they wick like crazy.

[nalrac]

Cool! That's a good idea. Would silicone gasket maker work for that as well?

[sprocket]

I use clear cause it looks better...sure you could use high heat red if you wanted to... but there is a difference between RTV silicone and silicone gasket maker...not certain what it is, I never liked the gasket maker...

[nalrac]

OK. Well, what I have is "Blue RTV Silicone". I imagine that would do the trick.

The issue seems to be that I can't be sure that is the only leak. Unfortunately, it only leaks when I take it down the road. Any ideas how I can't get it to reveal itself?

[jct842]

like sprocket says loose the synthetic oil. there is dye that can be put into the oil, imagine an auto parts place may have it. for an out side leak repair I would only use the red high temp stuff. when you are on the road your engine is going to see much higher temps than at idle. cracks have been known to open up when they get hot then close back when the temp goes down. john

[Bashan]

Here is the right case cover coming off. Before any of this happens you need to remove your stator which isn't that big of a deal:

Now, Blue RTV....a lot of guys use it for everything but if you look on the label it has warnings about contact with oil and especially gas. Yet when I go in the local Auto Weinie down the street they start waving Blue RTV around as if it's a cure for all disease. If you're going to try that route Sprocket is right about the clear silicone, it just seems to stick better. If you're going to go RTV use the red or black. John has a good idea with the oil dye. I think you said you had your plastic cooling shroud off once. If it was me, I'd take it off again, use the dye, and take it for a spin. Don't go so far you'll overheat it but it shouldn't take long to figure out where all the oil is coming from.

If I can interject my opinion here, you're going to spend a lot of time trying to fix this oil leak and end up with an oil leak. Once you develop a problem like that it's not going away. You can get a seal set and split the case but if you're not comfortable taking an engine apart this could be problematic. If it was me, I'd look into a complete engine and swap it out. If you try to replace the seals you're going to have the engine out anyway. Get an engine, you've got spare parts for a winter's project, and your leak is fixed. JMO, Rich

[nalrac]

Thanks for the suggestions. I'm leaning heavily toward just replacing the seals. I don't want a temporary solution. I want it fixed.

Also, I'm thinking about grabbing some UV oil dye. This looks like a great way to find the leak, IMO.

Finally, Rich, I appreciate you opinion and would absolutely do a full replacement if it was within my budget. But, $50 compared to $300+ is a big difference. I'll try the fix first.

Thanks!

- Adam

[drjeff]

I have seen new engines on Amazon.com for ~$239.00.

[nalrac]

drjeff, right, but as far as I can tell shipping is usually around $70 or more.

[sprocket]

I would be very careful about those grey market engines.. some people have done OK with them other haven't. Sort of buying a pig in a poke...

[mmm1966]

I have always used the "ultra black" silicone gasket maker . A lot of different auto makers use it in place of gaskets on the pans. It is some tuff stuff and once it dries it wont leak.

[nalrac]

Positive update! ;D

I found the leak. I used InterdynamicsUV Oil Dye (bit.ly/rftIF4) and used a black light and it was beautiful. The leak glowed so bright I couldn't miss it.

Fortunately, I didn't see any other leaks at all. The only leak that I found was at the back of the crankcase. It's definitely a bad gasket because it's leaking out right along the seal. The location of the leak is circled in the image below:



I'm going to order this gasket and install it over the weekend (bit.ly/nzDrV6)

Let me know if you have any thoughts,

Adam