I notice after about 1500 miles or so i have to top off with between half to full quart in my oil cooled 107, using regular castrol gtx 20w50. Would using 10w60 as a full oil change be better than topping off with sae50 or sae60 with the 20w50? in heat indexes of 115-120 degrees? Temps in the west are 120 today.

 

115-120 straight 60

 

there is no advantage to using a 10w60 oil in a harely, unless it is subjected to VERY cold temps. you might take the suggestion of running a straight 50 or 60 weight, but my suggestion would be to try Specto 25w60.
the weight of the oil is most likely not contributing to the engine using oil. do a quick compression and leak down test and try to get a better feeling/data on how well you rings and valves are sealing..
the motor company used to allow 1qt of usage in 1000 miles, which i thought was absurd, but it was their spec and i couldnt fight it with the tech guys, no matter how hard i tired.
m

 

oil weight of today is no way near of old.
research the subject.
i agree with mr. marco
it wasn't a warranty issue till 500/qt. my out the box 1974 ch used 1000/qt till it got a rebuild at 175k miles and it was only done as a bird in hand as the main deal was frame restoration. the funny thing is i used what ever i had on hand from 30 to 60, mostly diesel engine oil, maintenance was an over kill though at 2k miles till rebuild and added spin on filter system then i up to 3>5k

 

 

A quart every 1000 miles? I give harley credit for really going retro with the new bikes by going back to a constant loss oil system.

 

Straight 60W in that high ambient air temp environment.
Service manual calls it out.
Scott

 

research mr. mj research
you found the keyboard so i know you can find the net.
another interesting subject is does oil really change weights as in multi-vis oils.

 

That spec is quite common throughout the auto industry Ford , Porsche etc

 

my 'comment' pertained to how painful and drifting in and out of relevance yours was to read, spelling, grammar..pretty rough
"my out the box 1974 ch used 1000/qt till it got a rebuild at 175k miles and it was only done as a bird in hand as the main deal was frame restoration. the funny thing is i used what ever i had on hand from 30 to 60, mostly diesel engine oil, maintenance was an over kill though at 2k miles till rebuild and added spin on filter system then i up to 3>5k"