What are you running for octane in the twin cooled 103? Recommended 91, but I know in the metric world a lot of people run regular and believe the bikes run better.

Any advice is eagerly accepted by the newbie!

 

I run 94. That is the only fuel I have used since day 1.......

 

I'm not sure I can even get 94 in Ontario. I know I can get 91, which is what the manual recommends.

 

If You run regular it will knock and ping.I learned by accident!Grabbed the wrong pump handle and said, oh well,filled up.Pinged and knocked until I filled with premium gas.

 

The new FLHTK's are 10:01 compression...

I got a bit of ping yesterday running 93....

But that was in a stop and go traffic jam here in San Antonio with AAT of 100f and ET of 260f.

I wouldn't run lower.... but I wouldn't stress searching for higher either.

 

I try to find 100% gas foremost.

It's usually at least 91 octane.

 

In chicago area I get 93. Never saw 94. Somestations have "racing fuel" which is 103 I believe but never tried it.

 

I'd stick with 91. The ECU will back out timing if it detects knock so you may not hurt anything with lower octane but you sure as hell won't help anything.

I'll tell anybody all day not to run more octane than they need, but these engines really should be running on premium.

Also the metric bikes don't really compare. When conditions are right you can make more power with less octane, however you need octane to cope with more heat and HD's liquid cooling almost isn't liquid cooling at all. Those metric bikes run a lot cooler.

 

Octane is additives to reduce pre-ignition of gasoline. It in itself does not increase performance. 91 is the minimum HD recommends for the 103. If you want to give lower octane a try, go for it. But, I'm betting the first hot day, pulling a hill, or accelerating you will wish you hadn't tried to save $2 on a fill up. Be prepared with some good octane boost like Lucas, when you find out why HD recommends 91.

The 103 is a low RPM torque monster. The torque partially comes from compression. Where as stock metrics are rev animals, and many have lower compression and can run on lower octane. Don't even begin to compare the 103 to metrics.

 

I run whatever the pump premium is around here, 92 I think.