'85 Front Fork Oil Level

[balky1]

I know this info is here somewhere but I simply can not find it. I know the capacity and I found the level info for later forks but I just can't find the info for the 1985. Someone?

Thanks!

[FJ_Hooligan]

120 to 130mm with tube/slider fully collapsed and no spring.

Then do yourself a favor and expand the fork, install the spring and make a measurement of the oil level in this condition.  That way you can change the fork oil without having to collapse the forks to measure again.

[Pat Conlon]

This sure makes the getting the oil level easy.

[red]

This sure makes the getting the oil level easy.

Pat,

Assuming for a minute that I will buy that nifty gadget, what is the oil level going to be, with the forks extended and the springs installed?
Thanks.

[Pat Conlon]

I don't know....I always measure with springs out and fork lowers collapsed.

I always take my forks off to change the oil. Once I take the cap off and it's no big deal to take the springs out, then I turn the fork tubes upside down and drain them overnight.

[balky1]

120 to 130mm with tube/slider fully collapsed and no spring.

Then do yourself a favor and expand the fork, install the spring and make a measurement of the oil level in this condition.  That way you can change the fork oil without having to collapse the forks to measure again.

Thanks!

I've seen that level for later models. Are you sure it applies to an '85?

[Old Rider]

Here are a pick from the workshop manual for FJ1100  it says 424 cl  it says to use 10w30 engine oil. You can use forkoil bot keep in mind that if the label says 10w  the viscosity
Can be very different on different brands or if they are mineral or synthetic based. As an example i once used castrol 10w mineralbased and later i used castrol 10w synthetic and the synthetic made my forks way harder and very harsh compared to when used 10w mineral because the viscosity is almost 3 times thicker in the synthetic version.
. I don't remember what the viskose index at cS@40C should be but i think it is 15  cSt@40C on the fj.  Now i use Yamalube 5w and that works for me maybe a little soft so maybe
i try Yamalube 7.5w next time.
Take a look at this viscosity chart and see the difference on castrol 10w synthetic vs castrol 10w mineral
http://mahonkin.com/~milktree/motorcycle/fork-oil.html

[Old Rider]

Here is another pick from another manual that shows the level ,but on the 1100 it is not specified.
Caution !!! the the manual here has a big fault and that is the torque value on the oildrain bolt- it says 43 NM that is way to hard and will strip the treads .21 NM has worked for me

Wait there is more faults in this pick (manual) and that is the drive chainslack it says 15-20mm and to measure with the bike on centerstand. That is way to tight. when riding  the bike and will stretch the chain and make heavy load on the transmission output bearing. Take instead the measurement 15-20mm when someone is sitting on the bike .

[balky1]

Thanks, I have both of those manuals.
I know the capacity, but problem is measuring that amount. Even with the laboratory measuring cylinders I have, it is hard to get it correctly because oil is very viscous and some always stays inside the measuring cylinder. Plus, there's always some oil left in the legs if you don't do a complete rebuild, which I'm not planning to, and I end up with wrong level. I suppose there's not much harm in +- 10 mL, but measuring the level seems also easier.

[krusty]

I would normally use ATF but, as my 1200 has the RPM kit I go with the recommended Motul.

[Pat Conlon]

"I know the capacity, but problem is measuring that amount. Even with the laboratory measuring cylinders I have, it is hard to get it correctly..."

Experiment with different levels on the fork oil, was one of the first things I did to my oem damper rod forks on my 84 to try and keep the fork dive away. That and a longer preload spacer. Progressive springs were the next step.  These were the days before Race Tech made their cartridge emulators.

Try a little more fork fluid....you may like it.

[red]

120 to 130mm with tube/slider fully collapsed and no spring.
Then do yourself a favor and expand the fork, install the spring and make a measurement of the oil level in this condition.  That way you can change the fork oil without having to collapse the forks to measure again.

Guys,

Indeed, Yes!   ^^^^ THIS!  And then please do share the measurement results with the rest of us.  Thanks.

[FJ_Hooligan]

120 to 130mm with tube/slider fully collapsed and no spring.

Then do yourself a favor and expand the fork, install the spring and make a measurement of the oil level in this condition.  That way you can change the fork oil without having to collapse the forks to measure again.

Thanks!

I've seen that level for later models. Are you sure it applies to an '85?

It's what I've been using on my '85 for decades

I also use 120 to 130mm for my FZ1s

[balky1]

I finally got the time to swap the front springs. I measured the oil level with springs in and forks extended. It is 270 mm. While this works for me, it might not work for you because you don't have the same springs (different gauge wire or more/less coils in oil).
I've put the 10W oil level to 120 mm (compressed and empty) and will see if it needs adjusting.