Please note that there was a comment on our site indicating a problem with the current Harley-Davidson brand synthetic lubricant. We have it from a reliable source at the motor company, as well as from several H-D dealers, that there is in fact NO problems with the current or any of the past H-D Synthetic lubricants. Harley Davidson dealers are continuing to sell the product as well as use it in their service departments.

We apologize for any confusion the previous post may have caused.

Thanks for the clarification on that.

Saw a couple of comments on the synthetic vs oil poll regarding Amsoil.

Is Amsoil different then the other Synthetics?

What makes it better?

I have been running AMSOIL in both my harleys(ok one of them is the wifes) for the past four years. I average around 15k a year. I do a complete fliud change in the spring. I am running 20W-50 MVC in the Engine and the Primary and    75W- 140 SVO severe gear lube. I change my filter every 3-5K  add what is needed. My bikes run cool. The highest my 06 Road king 95 " has ever got with AMSOIL is 224. Below are some links that can answer some of you questions.   Thanks

 http://www.cyclefish.com/forum/topic/11/index/74

https://www.amsoil.com/lit/G-2156.pdf

http://www.amsoil.com/articlespr/articlegreatdebate.aspx

http://www.jlh-oils.com/

I have personally never ran Amsoil in any of my bikes, but I am hearing more and more good things about it. Guess I'll give it a try and let you know if I see any difference.

I've run Amsoil Synthetics in all three holes in my last 4 HD's and have no complaints. 20/50 in the engine, 10/40 and 75/90 gear lube. It doesn't leak or burn but I do trade or sell my Bikes between 10 and 25K miles.

Synthetics all the way,period.

I'm getting in this disscusion a little late and have read the previous postings all with good info, the question I have is , can you run the stuff in older evos? I've gotten conflicting info, the most disturbing is that it is so slick that your bearings won't spin correctly.

I have never heard of any problems running the syn in the Evos. As a matter of fact the following statement is on the Amsoil site....

According to Harley-Davidson, one of the unique benefits offered by Screamin' Eagle Synthetic Motorcycle Oil is its versatility. For the first time the company is recommending and oil that can be used in the engines, primary chain cases and transmission of most Harley-Davidson motorcycles, including Evolution XL, Evolution 1340, Twin Cam 88 and 88B, Revolution and Buell models. This feature, however, is not unique. AMSOIL 20W-50W Synthetic Motorcycle Oil may also be used in the engines. Primary chaincases and transmission of these applications, providing superior lubrication protection in each component.

I'm not a mechanic and don't play one on tv.

I've always used Royal Purple. Because it works, and it makes it easy to figure out which one goes in which hole. You can use it in all three hole. 20W50

YMMV

I have been a certified harley tech for 10 years now and I can tell you it all realy depends on the aplication and outside temp. As for the whole should I run Synthetic I can only really see doing it for fluids that don't get changed much. even then it is still not worth the cost. If you maintain any vehical at its recomended intervels or more your not going to have an issue.  evo motors were desinged to go 80K plus before needing a remaufature to bring back to stock specs.  Twin cams are 100K plus be reman.  If you are beating on your bike: cold starts, excessive reving,  burn outs, no clutch shifting yea you want sythtic. It sticks to metal parts or metal parts can absorb it a little. 
In other words if you are nice and care for you ride  you dont really need synthtic. If you beat the crap out of it yes you do.

Full Syn. Rotella T Syn in everything I own.

Amsoil all three holes

I bought my Suzuki Boulevard C90 new. Did the breakin miles and the First service. Used Amsoil in the Motor/Transmission and also the shaft drive gear. The Motor ran cooler, Clutch Gear was quieter, shaft gear cooler, and milage increased 1.2 mpg over next 1200 miles. Oil cooled ran nice in an escourted parade that walked near a half mile while some others were smokin. I will stay with it

I use synthetic oil in my 2010 street glide. so far so good!!

Use conventional oil until your bike is broken in, then switch to Amsoil Synthetic Oil.

This is a rather lengthy article but addresses the difference between synthetic and "dino", breaking in with synthetic and viscosity.  The author recommends synthetic oil for unit constructed engines, like the Sportster or Big Four bikes and feels you get the most bang for your buck with Rotella T Full Synthetic.

All About Motor Oil (LINK)

Yes,,, The author is correct that Rotella T Full Synthetic is good and readily available. IF YOU CAN NOT GET AMSOIL, then you should buy Rotella Fulll Synthetics until you locate your AMSOIL SYNTHETICS Motorcycle Oil. Amsoil is THE BEST synthetic oil out there. Follow this link and read comparison test: 

http://www.lubedealer.com/embry-synthetics

What syn would be an improvement for a wet clutch in a Honda 4 stroke motor? Been running the Honda oil w/out moly since I purchased the bike,per the manufacturer instructions.Change the oil at 3-5000 miles,yet I have never noticed any metal shavings? Do you use magnification to see the shavings?
TIA