All of the oil reservoirs on our bikes have levels, to which they should be filled. The quantities or fluid ounces in the manuals are only a guide - in other words have this amount to hand before you start.

 

First timer asking question here. I don't see anybody stating proper orientation of forks while checking oil level. Installed and at an angle or removed and basically vertical? Impression I get from the manual is that they would be removed during this service. also according to 2012 FLHTK manual, lower leg should be pushed up all the way on the tube when using depth gauge with syringe , but again i don't see any one here stating that?

 

Doesn't make any difference, as far as fork legs are concerned. When tipping them over at the stock angle, the mean level of the fluid is going to be the same as if they were vertical. Also the diameter of the forks is small enough that as long as both levels are the same any difference compared with measuring them when vertical is going to be negligible.

 

You're right. The viscosity of fork oil can significantly impact the suspension's performance. It's generally best to stick to manufacturer recommendations or experiment with minor changes. 20W and 30W could indeed be too high for many models, potentially causing a harsh ride. Always refer to your specific bike's manual for accurate specifications.

 

 

I have a 2002 heritage classic I use 20 weight with 1000 miles on the oil, and it bounces very easily just pushing down on it

 

Why wouldn't someone buy a manual for a vehicle they own and desire to work on? Even the cost of new manuals is less than 3 shop hours.

Ebay and Facebook market place is where I've found OEM manuals. Sometimes mmfoubd manuals on DVD that are searchable.