We all get it, at some point they will all do it. Mine did it early on in its life, right around 3K the rear went from weep to drip drip in a weeks time and 2K later the front started. So I replaced them with the Newest version and the drip drip stopped. However there was from day one after the fix just the smalles amount of weep, just tnough to get wet enough to grab brake dust and other grime. A swipe with the finger and it was good till next week.

Well about a month ago I did a good ride on the slab and got caught in barely creeping traffic on a hot day on oil a few hundred miles past change time. My Castrol 4T dino was toasted. I was not too happy to change the oil only to have to change to my winter oil, for I ride all year, a short time later and waste money and natural resources. So I plunked down at the computer to find a nice synthetic for year round use. Never ran it, EVER in anything so I know next to nothing about fake oil. I was ready to use anything and I have only used Castrol since 1990 in all engines I own. After looking at some stats like cold and operating viscosities and most important the viscosity index, well I learned a few things about fake oil. I now know why M1 15W50 is so popular! There is not a single MC oil out there that can compare, even at twice the price. Only thing I do not like is the low operating viscosity is just over a 40W, but it has solid HTHS numbers. In the end I chose Castrol 20W50 Power RS. With a viscosity index of 157 (real close to the 15W50 M1) it is going to thicken up less than M1 20W50 v twin and MCV is only a 147, still decent but M1 is easier to get and has strong numbers. The Power RS is dang near 60W at operating temps and is thinner at the cold viscosity. After almost a month with this fake oil the noise level is the same as dino oil. Cold and full on hot starts are like the first start of the day and I do indeed notice less vibration

Thats a big lead in there, but here is where the weep/leak at the rocker box covers comes in. It took me almost a month to notice but here it is. That little bit of wet she got at the covers, it is NOT there anymore. Nothing at all. Today I noticed what I would descride as a little bit of crust poking out between the two parts. It looked and felt like oil that had been cooked to a crisp, the old oil left over after the minute amount evaporated off and cooked the rest to a crust.

So as of right now, this being my first and only experience with fake oil is there is no extra noise. There is no extreme leaking going on like dino fanatics (even I probably said it in the past lol) will claim all day and night. And my final observation is M1 15W50 is a solid MC oil with several members here that use that oil as testament. I tend to ride on the hard side so I wanted the extra viscosity at full operating temps. Oh and one last obseravion. The oil temp differences everyone reports. I have yet to notice overall temp differences. What it does do is shoot up to 150 a lot faster then stay there and slowly climb to normal temps and drop quickly at stops. My guess is in extreme use it might stay cooler, or just take longer to get there or cool quicker, who knows. As of now it just takes a lot longer to get there, but the temp is no different once it gets there.

So if you have a minor weep at the rocker boxes after the latest revised rocker box gaskets have been installed, try some Castrol Power RS 20W50. Pretty solid oil as of right now. Also switched to a Hiflofiltro HF170B oil filter (same thing as the K&N without the nut for half the price), gathered if the oil lasts for a longer OCI I would want a filter to match.

 

Good write-up. I've been a synthetic oil fan since the beginning, but, I have found that my sporty likes dino juice better. I ran M1 in it initially; I do think it keeps the bike cooler, and no doubt more lubricated, but it was LOUD. I'm not one of these guys that gets freaked out by the noisy sporty engine, but this puppy was exceptional. I finally decided to try going back to the dino, and it is notably quieter, yet still comfortingly noisy as all sporties should be. I run 50W GTX. On the leak, I just finished dealing with this also. I installed the updated seals and decided to lap the rocker box covers flat on a polished piece of marble using 400 grit. Those things weren't even CLOSE to flat, but they are now, and it only took 30 minutes or so to do. So far, no leaks.

 

The rocker box leaks are not oil dependent. If you get them, they will leak regardless. It's just a fact of life. Pretty cheap if you ask me.

 

Bones, I ran some Syn3, then had a leaky gasket, I replaced the rocker cover gaskets with Cometic gaskets and at the same time started using RevTech 25w60 dino. I have not had any sign of leakage. I changed the gaskets about 7,000 miles ago. So far so good. The leak is obvious and right where it, (the gasket) leans outward. There is a light black film on the inside surface of the gasket. It was obviously doing some breathing there. I don't know if the oil had anything to do with it, but that's the story. The front did not leak but I changed it any way.

 

My rear head started leaking. I bought Custom Chrome head covers, spacers, and lower parts. My 2003 has a 3 piece head setup.

They all leaked. But that being said the Harley stock parts leaked also.

I was told that the Harley parts would not leak. Well I bought the Harley parts and the front cylinder has yet to leak, but the rear cylinder has not STOPPED leaking.

 

I also used a piece of marble to check mine. They were as flat as could be. I spent more time trying to find a reason to lap them than it took you to do yours.

I know Harleys are very much individual bikes. What works in mine will never work well in other bikes. I am still a huge fan of Castrol dino oil. Never failed me and even after frying the oil it would have still protected the motor. If this does not work out in the long haul I will go back to dino. But next summer I will be back in MI so the over 100F days will be once a decade if I am lucky. As of right now I kinda dig the no extra noise level and how hot, warm and cool starts are the same. The oil is the same thickness no matter the temp, but we will see when it hits 10F, where even dino 10w40 starts slow. I cant wait for it to get cold!

Scuba, from what I read symthetics are horrible for seals, so they put seal swell additives in the fake oils. I will go out on a limb and say this oil has them seal swell agents in it. Something in the oil stopped the wetting weep it had, and my bet is on it was not me twinkling my nose to stop it.

 

I don't think it's that they are horrible for seals, I think it's that they have a smaller molecular structure, and will often leak through where dino will not. I have experienced this in a few of my automobiles, but not the bike.

 

That's not true, wherever you read it. Almost all oils have some sort of swell-causing additives in them.

Seal swell occurs due to a reaction of the additives in the oil with the seal material. There are specific types of rubber that do or do not react well in the automotive environment. One symptom of poor material choice is the seal can swell too much. This can cause it to break, disintegrate, or other failures.

Mineral and synthetic oils naturally allow some seal swelling, and this is accounted for. The difference between the two is not all that large. Mineral oil tends to be slightly higher. When the OEM tests their engine and specs out fluids, one thing considered is seal durability, which includes the amount of swell allowed. Generally though, in the life of a motor, you're not going to notice any difference between one oil to the next.

In the typical case of high-mileage oils having extra additives to promote seal swell in order to stop leaks, you're really doing more damage than good. The seals weren't designed to be swollen like that and will eventually fail, usually in a more grandiose fashion at that. If you've got a leak, you should really fix it.

Any oil that actively promotes seal swell beyond normal, is NOT approved by ANY manufacturer. That includes some of those high-mileage or stop-leak types as well. It may work temporarily to fix your leak, but just think of all the other seals that are swelling that were not designed to or did not need it.

The bigger reason, and the actual cause in 99% of cases, is the difference in molecule size. Synthetic is much smaller, so they may leak out of something a mineral oil gets blocked by (think of big fish getting caught vs small fish escaping in a cast net).

 

No, it is true. Olefins are known to shrink seals.

I did fix the original leak.

Synthetic oil molecules are uniform in construction, they are not smaller. So the net has non uniform holes, some being larger than the others and some of the smaller fish just swim out (that ever so small amount of wetness I observed).

Maybe, just maybe going waaaaay out there on this one. Just maybe BP tribologists actualy designed an oil for Harley Davidson V twin engines, and just didnt print it on the label to gain sales. Whatever the case is there is no synthetic oil leak, there is no jar full of rocks extra noise. Just a product that lives up to its claims. That just happens to thin less at operating temps and thickens much less at cold temps. Ya know, a product that performs with no white paper wild claims with secret handshakes just to buy it. I can dig that.

I always looked at that little bit of wetness and wondered when the drip would return. I dont wonder anymore, but the day it gets wet or drips again, if it does, I will come back here and let yall know 'bout it.

 

OK my stupid question of the day. When you replace the rocker box gaskets don't you put any type of gasket sealent on them? I've not had this problem on any of my bikes before. maybe I'm just lucky or sold the bikes before experiencing this