Harley air breather-oil issue and filters. . .

[Robster]

I've got an '03 Harley Sportster 1200 that I've been running Amsoil V-Twin oil in and using Amsoil Superduty oil filters and I've had the common problem of oil blowing out of the air cleaner (small amounts, just enough to make a mess). I've been happy with the quality of Amsoil products thus far, but during a recent oil change I found myself lacking an Amsoil oil filter, so I put on the appropriate Harley filter instead with the Amsoil oil. To my surprise the oil stopped blowing out of the air cleaner immediately after switching to the Harley oil filter. Since the oil change I've run the bike at low speeds, high speeds (75-80 for @90 minutes at a time) and speeds in between, without the leakage that was occuring with the Amsoil filter.

I've racked my brain and the filter is the only thing that has changed since the last oil change; the air filter is the same one (original equipment).

I'm certain that the Amsoil filter is a quality product, but now I'm wondering if perhaps it is too restrictive for the Harley's relatively low oil pressure which is resulting in a pressure build-up in the case (causing the oil to blow out the head breathers). If this is the case, perhaps Amsoil should be made aware so they can design a filter that meets this need.

Has anyone else made this observation? Could an Amsoil rep comment on my observations? I'd be glad to give more information if needed.

Regards,

Rob

 

[KW]

I don't see how the oil filter and crank case vent would affect each other. In any case I'd leave the Amsoil filters of the bike and use the other ones.

 

[garyb80]

On Harley engines, there are two parts to the oil pump. There is the feed side from the oil tank to the engine, and the scavenge side from the crankcase, through the filter, and back to the tank. If the filter is too restrictive, the scavenge side of the pump can't keep up and excess oil backs up in the crankcase. The only place for the excess oil to go is out the breather. No engine harm is done because there is no oil starvation to the motor, but it does make a mess.
Make sure the filter that you are using isn't one that should be used on the TC 88 motors. That filter is much more restictive than a Sportster filter. If you don't want to run a stock Harley filter, J&P Cycles has some good oversize, low restriction filters. Some even have magnets on the inner core to catch ferrous particles that might have worked through the filter media.

 

[Dick in Falls Church]

Robster-
I recommend you send the info to AMSOIL and see if the tech service department has any explanation or comments.
You can contact them through the AMSOIL website.

 

[Robster]

I'll probably continue using the Harley filters until Amsoil comes up with something different; the Harley filters have a good reputation for quality and they're a little cheaper than Amsoil anyway.

I've been using the recommended Amsoil oil filter for this model bike, and the problem may only affect this model (Sportster 1200); that's why I posted this topic--to see if anyone else who had this problem had the same experience after changing filter brands.

I just sent Amsoil's tech support a copy of my earlier post describing the problem. I'll be sure to post their reply when I get it.

Rob

 

[hk33ka1]

I can't comment on the Evo XL but on Twin Cam HD filters and Revtech Tc88 filters there is a bypass valve. Amsoil HD filters do not have a bypass. I have been running AMV in my TC88 Softail for a couple of years with no loss or breather leaks. I always use the HD OEM filter.

 

[arkainzeye]

sounds to me like what i just went through on my kawasaki vn800B. In my case it had nothing to do with the filter. it was too Much oil in my crank case. and i removed the filter and drained oil out of it , then reinstalled the filter. and i NO longer had this problem. for me this problem was a fine oily mist that would get all over my chrome. 8( I wonder in your case by changing the oil filter you just lessened the amount of oil.. but i could be wrong as i don't fully understand HD's oil config. i just wanted to share what happened to me..

 

[KW]

Harleys have a dry sump. The oil is kept in an oil tank and is pumped throw the engine. Then it is pumped back into the oil tank. This enables them at have a smaller crankcase.

 

[Robster]

The Amsoil filters DO have a bypass valve according to their literature. . .I've never heard of an oil filter without one anyway; I'm still waiting on Amsoil's reply.

Regards,

Rob

 

[BobbyB]

The Amsoil filters do have a by-pass valve. I put one on Sunday and could easily see it.
Bobby

 

[Mike_dup1]

here are the features from thier web site

• Traps Dirt Throughout Media Thickness
• Up to 100% More Capacity
• Up to 20% More Efficiency
• Built for Rugged Performance
• Heavy-duty Steel Case Withstands Extreme Conditions
• Assures Oil Flow With Relief Valve
• Prevents Oil Drainage During Engine Shutdown

 

[road_rascal]

Find a copy of May 2004 Motorcycle Consumer News. Great article concerning Sportster oil blowby and how to fix it.

 

[Robster]

The documented fixes for oil blow-by are numerous. . .what I'm thinking is that people are applying these "fixes" for a problem that could be solved by simply changing their brand of oil filter. Personally, I like the path of least resistance. . .or. . .if it ain't broke, don't fix it.

Rob

 

[hk33ka1]

Perhpas the Amsoil filter I recieved was an older one, it did not have a bypass valve or spring visible, I did not cut it open. I gave it away to someone else and continued to use HD filters. I have also seen the Revtech TC88 filter and it does have the visible bypass. What part number was the Amsoil with a bypass that you had? I cannot recall the one I had but it was the number that www.amsoil.com listed for my Twin Cam.

 

[Robster]

The by-pass valve (spring) is located at the top of the filter (opposite end from the threaded hole) and cannot be seen by looking into the filter. What you may be referring to "seeing" is the anti-drainback valve. . .it has one of them too and it can be seen!! Every filter made today has a by-pass mechanism to prevent engine oil starvation, and I believe all must have the anti-drainback valve too, but I may be wrong on that.

I've had Amsoil and Harley motorcycle filters apart and they are both well-constructed, but I'm thinking that the Amsoil filters might be a little too restrictive for a Harley application--as I said before, I'll post Amsoil's reply when I get it.

Rob

 

[Pablo]

What oil filter part # are you talking about?

 

[msparks]

I don't have any comment except that has this done it with multiple Amsoil filters or just this one?

Would you be interested in trying it again to see if the results are repeatable?

Could have just been a coincedance.

 

[garyb80]

On the Sportster (and about every other Harley that comes to mind), the filter is located well below the crankcase and the oil tank. An antidrainback valve is unnecessary in this app. There is no place lower for the oil to drain to.

 

[Robster]

I've changed the oil on this bike 3 times (8500 miles); the first two changes were with the Amsoil filter; the oil blow-by occurred with both Amsoil filters.

I now have the Harley filter on. . and no blow-by. I'd be willing to try another Amsoil filter for a test.

Rob

 

[Robster]

Hmmmmm. . .no reply from Amsoil yet. . .kinda discouraging. . .thought they'd be a little more responsive.