I have committed bike abuse I know! I have only put around 3000 miles on my Heritage in 18 months. It has HD full synthetic oil in it. I am wondering if I should change it because of time or would I be throwing away perfectly good oil away? Thanks for your input.

 

I don't consider it bike abuse. I change my oil in my bike at 5K or at the start of each season. Usually I'll ride about 5K a year here. If you live in a colder area where you aren't riding in the winter, I'd prob change it at the start of next season if you're putting the bike away soon. If it's an area like where I lived years ago (Vegas), I'd change it at 5K. But I don't see the harm if you're running Syn

 

The factory recommendation for engine oil changes is every 5000 miles or one year; whichever comes first.

 

Manual is based on dino oils. Personally, I wouldn't change the synthetic, I'd put another 2K on it unless it was going to sit up another 18 months.

 

Most oil manufacturers (even synthetic) state 5K or one year. Which ever comes first.

You spent a lot of $ investing in your bike, feeding it new oil every year is such a low cost to see it last you a very long time.

 

My opinion would be to change it unless you are going to park it for a while. Then I'd change it when you get it back out again.

 

You've gone the 18 months. When in doubt and you've got the money, just change it. I don't put all that many miles on my bike and will probably do mine before then. It's fairly cheap to do and I'm sure your scoot won't hate you for it.

 

yes u would be synthetic is good for 10,000 unless it's dirty as hell I would leave it. I use dino oil change it every 5,000. u think if oil sits it will go bad. don't believe all the hype it will be fine. u should ride it more.

 

Remember your oil has just as much to do with cooling the engine as it does lubrication in an air cooled motor! Watch your oil temp! If I have sat in traffic and my oil gets to hot I'll change it. As soon as it starts breaking down it won't transfer heat or lube as efficiently. I've changed my oil with as little as 500 miles on it. When you spend 20k on somthing why wait as long as you can ? $20 - 40 for oil and knowing my bike is in top running order is a no brainer for me!

 

Its not the oil thats going bad sitting there. Its the contaminates it picks up.
I like Baker's explanation. Figure it applies to the engine oil even more since the combustion has air & carbon.

Q: How often should I change my transmission & primary fluid?
A: At least once a year, and preferably when you do your ‘before’ winter service. Oil, once exposed to oxygen through the vent, will begin to attract moisture and other contaminants that can eat away at seals, rust parts and degrade the fluid. A transmission breathes through the vent in the top cover as it is thermally cycled. As the transmission warms up, it exhales through the vent. As it cools, it breathes in through the vent. The primary drive housing also breathes through the vent in transmission top cover via the hole through the center of the mainshaft. Changing the fluid when warm is preferred as all the oil and its contaminants are in a homogenous solution and you will remove more of the heavy particulates and debris.

http://bakerdrivetrain.com/frequently-asked-questions