Fork oil for an 1985 RTL250? What do people use and what capacity?

Seals went on mine and changed seals but can't find anywhere what oil to use.

joe

When I bought my RTL back in the 80s, it came with an HRC manual. It describes a complex method of measuring down the inside of the fork leg to the oil meniscus. In practise, this equates to 250cc. Experimentation with plus or minus 20cc will make a significant difference. I use the recommended 10 grade fork oil. If I was able to attack the hard course (how I wish) or weighed in above 12 stone, a higher viscosity oil would be advantageous. I also use 0.5 inch long PTFE pre load spacers, above the springs, to compensate for the coil springs settling over 30 years of abuse.

The manual recommended 258cc of oil which should be 160mm from the top of the fork leg. You should move each fork leg up and down a few times before measuring to make sure the air has escaped. I do this by bending a bit of wire so that 160mm dips into the fork.

The oil is describes as SS8 hydrolic oil, which must be something close to 10 weight or I've heard of people mixing 5 weight and 10 weight, but I've never been that sensitive a rider!!

Thank you, big help both of you.

I'm certain while changing the dam seals I've misplaced - read that as lost, the spacer for the front spindle. Can someone with an RTL measure the width and diameter of there's. I can machine a new one up out of alloy but just need accurate measurements.

Will do that for you Joe, when I get home from work tomorrow.

Edit: sorry, just realised yours is an 85 drum brake model, mines a disk 88, so it won't be correct.

Edited April 8, 201511 yr by shedracer

Found it in the end mate, it must have got kicked out of the garage somehow and when I walked to the car I spotted it. bloody lucky!

Thank you though.