Oil leak mystery... By nalrac (Read 8,187 times)

[nalrac]

Hey Guys,

Here's (hopefully) the final mystery to solve on my scoot. I accidentally posted this elsewhere before I realized.

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?

Sprocket has suggested that I put some silicone around the seam. I think that is a great idea. Any other ideas?

Thanks in advance!

- Adam

Read more: .scooterdoc.proboards.com/index.cgi?action=display&board=150cc&thread=4871&page=1#ixzz1W5yqy5Ev" rel="nofollow" target="_blank">.scooterdoc.proboards.com/index.cgi?action=display&board=150cc&thread=4871&page=1#ixzz1W5yqy5Ev

[JR]

Got to realize that with the shroud around the engine that the fan pushes air through if hot oil is in any way near this area it can and will blow oil every where.

I had a very stranf hair line crack on the head on my bali and it only occasional dripped and I decided to try synthetic oil and the drip went to a nightmare. Replaced the head and canned the synthetic oil and all was well again.

The crankcase seams are very hard to seal with outside things like silicone becasue it's very hard to get the surface completely clean so the silicone can properly stick and seal and even then it's generally a short term solution.

We've got several how to manuals on the break down of the GY-6 IMO open it up buy a new gasket kit and fix it right and be done with it.

JR

[Doug in San Diego]

My 2 cents - Having had a few oil leaks.

I would be extra sure where the leak is coming from. I had a leak from the base of my cylinder, but it really looked like it was coming from the underside of the engine. The problem was, it was really just a slight sheen on the engine until it found somewhere to accumulate on, then a drip would form.

Same thing happened when I had a leak around the starter. That drip formed on the back underside

Really get your engine clean, then get a really really bright light. Turn it on, then watch carefully.

It would be a shame to remove the right side, only to find the leak is somewhere else.

P.S Before I cleaned it from both leaks there was oil everywhere, even up under the floorboards, so that is really no clue.

Doug

[jhbietz]

Oil leaks can be a real PITA. Hopefully you will just have a bad gasket on the rite side. This can be replaced without removing the engine. I use a Hylomar non-setting sealant on the gaskets.

[nalrac]

Thanks for the help, guys! It's been suggested that I use a UV oil dye to help find the leak. Any experience with this?

JR, I agree with you that I should do it right. If I find out that it is indeed coming from the right side then I will just replace the gasket.

Doug, I made sure to get the bottom extra clean so I'm pretty sure that it wasn't running and accumulating from anywhere.

What I've thought about doing however is stripping it down to the bare frame, mounting the seat on it, and taking it for a quick spin. That way, I can get the engine nice and hot and maybe help me confirm where the leak is coming from. As I asked above, would the dye help with this process?

Finally, it been suggested that I just "get a new engine". This is an expensive solution and seems to be the easy way out rather that the cheapest. Thoughts?

[jhbietz]

Yea, I read that one. Replacing an engine to fix an oil leak is kinda like using a nuke to remove a stump!

[JR]

Aug 26, 2011 8:33:03 GMT -6 jhbietz said:

Yea, I read that one. Replacing an engine to fix an oil leak is kinda like using a nuke to remove a stump!

Now I'm gonna remember that one! LOL ;D

[jhbietz]

Now don't be actually trying it JR. I'v heard them nucks is dangerous.

[nalrac]

jhbietz, funny! That's what I thought too

[austinbikergirl]

The majority of oil leaks appear from the valve cover o-ring. Have also had several with hairline cracks on lower right side of cylinder head. Wise to do a valve clearance ck/adj. while your changing cover o-ring. If you drive the scoot looking for a leak, it will still blow all over. It's better to lock the front wheel while on center stand, and let someone give it partial throttle till leak detected. Use caution as you wouldn't want the scoot to jump off stand while giving throttle; seen it happen, not funny.
Another thing is to check that your crankcase breather is functioning properly, not restricted.

[Doug in San Diego]

Keep us posted

[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

[nalrac]

So, I picked up a gasket yesterday. It took a while but I was able to get the cover off and the old gasket stripped. However, there's been some new developments.

When I removed my flywheel I noticed a quarter sized puddle of oil on the lip below the stator. After shining my blacklight on it I could see a trail of oil coming from the crankshaft oil seal. The seal itself was covered in oil (it was glowing really bright under the light). A leaky shaft oil seal explains more easily how the fan could be blowing the oil around.

Now, I have a few questions regarding this and the gasket:

1. I failed to get the size of the oil seal. What should I purchase? I want to pick one up today at the local shop.

2. I was able to use a razor blade and scrape a majority of the old gasket off. However, there's still some residue in a few places. How should I clean this off? Does it matter?

3. Should I use a gasket sealer of some type?

4. Anything I'm missing?

[JR]

Need to pull the old seal and then it can be found at your local shop hopefully is not then we can look it up on the net, some of our vendors here can help also.

Yes you do need to get all of the old gasket material off and using a razor blade along with a fine wire brush will do the trick.

Myself I like to use a thin coat of the high temp red silicone with my new gasket to insure a good seal, easy to get off if you ever tear it apart and does a good job to help the gasket seal properly.

JR

[nalrac]

Thanks for the response, JR. I will have to give the red silicone a try.

I'm not able to get to my bike to remove the seal today. Any idea what your Bali has on it?