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Primary oil for '99 Fat Boy......

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Ok let's start with I HATE BUYING STUFF THAT SAYS H-D on it for my bike....
That being said, I've been running 80-90 weight gear oil in my primary at first because I had a bad leak while on a 1600 mile trip then after I fixed the leak I saw no reason to change....... Basically I'm looking for some thoughts about this as far as what damage if any could possibly come from doing this.......


Thanks!! :cheers
 
Thanks for your quick reply Glider...... I guess I wanted to be sure that my newfound no charging problem wasn't somehow gonna fall back on what oil I used in my primary. I've tested as well as I can by using my H-D manual and pretty much the instructions on this site are basically the same, I had no light at the regulator prongs when using my test light and I unfortunately saw no VAC when using my multimeter at the outlet plug for the stator so I'll assume my stator took a dump on me so I'll replace it as soon as the money tree is ripe........
 
I think I would stay away from the gear oil in the primary myself.

Most any dino oil will do the job in there like 10-40 or 20-50 but without friction modifiers.
 
Glider you beat me to it.

No Friction Modifiers!

I run Mobile synthetic 75/90. But I live in Memphis area. Summer here is brutal.
 
Let me guess. I bet when your bike is stone cold and you drop it in 1st, it bangs.

My bike has gone into 1st a little hard on a cold morning but like wlbowers I also live in a very warm climate, Georgia and Florida along with my place in Pennsylvania, and the only time I really notice the bang is while I'm up here in PA. I never noticed any clutch drag or hard shifting at this point.

I'll assume the "No Friction Modifiers" comment is for the clutch pack so I guess when I put the new stator in I'll consider the Mobile synthetic 75/90 as an alternative.....

Thanks for your input guys!!

Rick
 
The synthetics aren't the best way to go in the primary either. They can cause slippage in the clutch when you get a few miles on them over a dino oil in the primary.
 
The synthetics aren't the best way to go in the primary either. They can cause slippage in the clutch when you get a few miles on them over a dino oil in the primary.

All right Glider, out of curiosity what do you use in your primary? I've apparently been doing wrong with the 80/90 so now you have me at a point in my mind where I should just use what I use in EVERY engine I have, Castrol 20/50.... Every bike I presently own from my '69 Triumph, '76 AMF Sportster, my custom and the '99 Fat Boy ALL run Castrol 20/50 bike oil and every vehicle I have uses Castrol 20/50 including my riding mower. I've used this brand oil since I was a youngster with no complaints, the '76 AMF was my first American bike and I still own her. She tought me how to wrench on a bike, LoL......... :cheers
Sorry to be beating this dead horse so severely, but I am always open to opinions with good reasoning behind them.

Rick
 
All right Glider, out of curiosity what do you use in your primary? I've apparently been doing wrong with the 80/90 so now you have me at a point in my mind where I should just use what I use in EVERY engine I have, Castrol 20/50.... Every bike I presently own from my '69 Triumph, '76 AMF Sportster, my custom and the '99 Fat Boy ALL run Castrol 20/50 bike oil and every vehicle I have uses Castrol 20/50 including my riding mower. I've used this brand oil since I was a youngster with no complaints, the '76 AMF was my first American bike and I still own her. She tought me how to wrench on a bike, LoL......... :cheers
Sorry to be beating this dead horse so severely, but I am always open to opinions with good reasoning behind them.

Rick

Is this motorcycle oil or car oil, big changes in the additive packages:s
 
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