Engine Knock When Hot
 

This is my first Harley and still getting used to the air cooled engines. While I was at the Laconia Bike Week I got stuck in some pretty dense traffic at Hampton Beach and the bikes got real hot. Was contemplating on pulling over for a little while but we were almost out of the traffic so we kept going. Not too long after when I released the clutch I could hear a knocking or clunking sound. That definitely made us pull over. Waited for about 45mins for the bikes to cool off and the drove away and it never did it again. Happened to me again yesterday in mild traffic but it's extremely hot here lately (Montreal). Any ideas what the hell that is and how bad it is? How the hell can you judge how hot the bike is with no heat guage?
Bike is 2010 Nightster with about 700miles on it.
Thanks

Get yourself one of those oil temp gage and don't ride if it goes over 200 degrees. Also have Royal Purple put in at your 1,000 mile service.

Man there is no way it gets too hot in Montreal for your Nightster.
Put in some 15/50 Mobil 1 and that alone will bring your operating temp down 20º.

A stage one is a good idea to help it run cooler also, the bikes come leaned out from the factory for EPA laws.

For the clunking noise you may need to adjust your primary chain more than likely.
Some Mobil 1 75/95 Gear oil in the primary is a good idea also. ;)

Don't ride with oil temp over 200 degrees???? What does yours run at?

E-

160-180 sometimes 190.

Also, don't sit in traffic, ride that white line or go around everybody on the shoulder. I had leo's see me do this many time, they don't do a thing about it, most leo's know Harley's are air cooled.

We were around or over 100º for almost the entire month of June. My bike pretty much stayed at 200º for a few 200 mile days.

Synth. oil and a good oil cooler works wonders. If your scoot is shifting correctly, I doubt it would be the primary chain that made the noise, probibally ignition knock from heat and lean condition. Pull your plugs and check them for carbon deposits, that will cause pretty much the same thing.

Thanks for the suggestions guys. Will definitely change oil types and get a guage.

Its definitely lean
 

Those bikes are way too lean from tha factory,Richen it up and u will be set.