Ok I have just purchased a 68 xlch. The guy I had purchased it from said that he had heard from a few a few mechanics that it is best to run 40weight oil in this well considering its a kicker It makes it kinda tough to kick.So I was looking in the seivice manual and they state
medium Heavy 75 grade above 40F
special Light 58 grade below 40F
Regular Heavy 105 grade sever e operating conditions at high air temperatures.

Now this is where I am lost and yes I am a noob first bike no clue as far as grades of oil I am suspecting I am suppose to use A 75 grade since I do live in MN. Know the question is is 75 grade = to 40 weight oil or is that guy filling me a line of crap lol. And can I use a lighter weight oil any help would be great or suggestions
Thanks Roger

 

I believe those numbers equate to straight 50 wt, 60wt, and 70wt. under 40 degrees 50 wt is what you want to use. might get by with 40 wt if its alot colder then that.Then 60 wt from 40 degrees to 70 degrees. over 80 use the 70wt. especially if it gets close to the 100's.

 

I ran 60 wt in my 75 xlch

[IMG]local://upfiles/20407/2DBA56F8572A4728A5EE2C87B57334EC.jpg[/IMG]

 

Run straight 50 or 60 weight in both the engine and the primary/tranny. You need the viscocity. The primary has a breather in it that will mix oils if you use different types so that's why you use the same in both.

 

I'd run 20w-50.

 

I had talked to the harley dealer they said not to run and thing real light weight cause of the cast heads still wondering about the whole thing

 

I dont know where your at but being its summer, I would't hesitate to use straight 50 wt oil ,or 60 wt if the motor is a little tired. In a older bike I feel 20/50 might be a little on the light side.

 

I've been running 20w-50 Pennzin my Ironhead for 15+ years with no problems.