Originally Posted by Bearcat1

Man, when I read the original post I had to do a double take to be sure it wasn't me that had posted it and forgot I did because the exact thing happen to me last summer in Arkansas on a trip. Temps were hovering near 100 degrees in June and a buddy and I were on a 6 day trip to the Ozarks coming from the Houston area. The first day of the trip we stopped for lunch around noon. When I came out from lunch and fired the bike I noticed some engine tapping that I had never heard before. It wasn't super bad so I just rode on and it eventually cleared out. Later on that evening we were close to Hot Springs Arkansas and found a hotel for the evening. Several hours later we came out to the bikes to ride somewhere for dinner and when I fired the bike it was tapping so loud I thought something may come apart. My buddy come over and listened. We checked around, checked the oil level, it was fine. I had Amsoil 20w-50 with roughly 1700 miles on the oil. Amsoil oil filter also. It eventually quieted down some so we rode on to dinner. The next morning we rode straight to Lander's HD in Hot Springs to have it checked out. They said the oil went bad and had broke down. So they changed my oil and filter. Never had the problem again. True story to a T. Since the trip I have switched to Mobil 1 and went back to HD oil filters. Been happy ever since with no more problems. Fortunately I didn't have to tear into my engine like they did Dave's to figure it out. I contacted Amsoil via email about the whole experience and the Amsoil rep came to the conclusion that he thought I acutally had an oil filter go bad instead of the oil going bad. Something to do with the anti-drain valve. Not sure if he was right or not but I didn't care. I could not use anymore Amsoil products after that experience. I was high and mighty on Amsoil prior to that. I realize it was hot out but I could not help but mention to the rep that there slogan "ride hard, run cool" was the exact opposite for me. I acutally like the way my bikes runs with the Mobil 1 better than the Amsoil did before the experience. Like they say, I guess each may be different.

Originally Posted by Quadancer

The change from dino to syn is noisier. The reason is that the molecules of dino are all different sizes and in the syn they are the same size. But this is also the reason syn has more shear strength, even though it "acts" thinner. So the noise means nothing. If clatter is apparent, valve train could be loose, but otherwise, there is slightly more noise. I get it from the primary and a tiny bit from valve train...but the engine running cooler tells me that there is less friction.

Originally Posted by Bearcat1

After I had more time later on to ponder my experience I have come to the conclusion that it was indeed a faulty oil filter that could not keep enough oil for the top end at start up hence the loud tapping until the oil got flowing and then it got quieter. But there again, it was an Amsoil oil filter I was using at the time. Must of had something to do with the anti-drain valve in the oil filter. I would bet anything that Dave's issue was probably the same. Especially since no damage was found to his engine. But having said that I am just not sold on Amsoil anymore. For me, the Amsoil was always a lot darker than what I find with the Mobil 1 when I checked the level at various times. To each his own I guess.

Originally Posted by bbflhrs

I read in another post where it is OK to mix oils. If I pull out 2 quarts of Amsoil and replace it with Syn3 do you think the noise would go away? I can't help but think that the clattering (or however the noise is defined) can be good for the engine. Has anyone done this?

Originally Posted by HDV-GLIDE

I have the same issue now with an Amsoil filter....Going to replace it tomorrow with a HD filter.....

It just started about 3 weeks ago....Tapping at start up and after a few miles, everything quiets down. Filter has about 2200 miles on it....

Originally Posted by RandyDowdy

I run filters from Drag Racing Specialties, and never have any issues. Expensive, but worth it.

Originally Posted by smokindave

Sorry for not getting back sooner, I had to go out after my post and never got back. Never thought I would get this many responses. I will try and answer them all.

First off I have been doing my own oil changes on Harleys for over 45 years. Before the trip I put in Amsoil 20-50 with a new K&N oil filter. The oil had maybe 50 miles on it before I left. I have been running the K&N oil filter for over 10 years and using Amsoil for about 2 years with no problems. I get average about 42 mpg on the highway and do not believe the I am washing the cyl's with excessive gas as I have never smelled gas in any oil changes or seen the oil as thin. Also the trip out to Sturgis does not involve any steep grades where you coast down long grades. The mechanic at Black Hills Harley cut apart my K&N filter and found no metal particles in the can ( good thing). My motor had over 4K on my new build before this trip and had been through 2 oil changes with no issues.

After the teardown and installing HD syn oil I rode another 5k over the hot desert twice and the bike ran fine. No black oil when I changed it again back home and no engine noises, so I don't believe I have an engine problem. I am not trying to sway anyone either way about what oil they use, only relate what happened to me. I like many others have used many other brands of oil but, this is the first time this has happened to me with ANY oil. I am as perplexed about this as the many that have posted but, feel I can no longer trust this brand of oil.