Request for info: 1992 Yamaha FZR fork oil weight and cc/mm measurement

[Pat Conlon]

Hello Folks, I converted my '84 FJ to '92 FZR cartridge forks (usd).
Does anyone have access to a maint. manual or shop manual for info. on these forks?
Need to know what weight fork oil was spec'd and what volume or measurement should I use in refilling these forks.
Unfortunately I have no info on what the PO used in these forks, so I will assume oem weight oil..
The forks already have 1.0kg/mm springs and I need to use a bit heavier fork oil for damping, so I need to know where to start on the oil weight and how much to add...

Thanks in advance...
Pat

[LA Mike]

Pat,

When I did mine I went to the fzr forum and they gave me some info. They said the manual has 15wt, but the fj is a bigger bike so I mixed 15 and 20 and used that. I have not mounted them on the '87 yet so I not sure how this is going to feel.

I'll try to find the oil level they gave me also it was about 16oz, but don't hold me to that. Do have the tool to take them a part they are a pain in the a$$. I made mine race tech's cost to much for something you use every once in awhile.

Michael

[Pat Conlon]

Thanks Mike. I'm gonna try new fork oil and see how that goes.  I was in a big hurry to get to the WCR and get the conversion completed so I just ran with the OP's oil. I should have at least checked the oil level but I didn't although I did set the sag. Typical last minute rush...
If heaver oil is of no help, I'll have to look at springing for the Race Tech cartridges and experiment with the compression and rebound shim stacks...Then I will need you to tell me how you made your tool (or borrow yours, wink wink)

At least once I get the Race Tech shims where I want them, I won't have to open them up again (unless a seal leaks)

Even though the FZR dampening was not up to the F3 level, between the added leverage of the wider handlebars and the stiffness due to the usd design, I really liked how the bike felt at Lake Sonoma...

Pat

[racerman_27410]

Pat,


A common misconception is that heavier fork oil for a heavier bike..... not true with cartridge forks.


the springs control the weight of the motorcycle   all the oil has to do is damp the motions of the spring.


in my FZ1 cartridge forks i run spectro 5wt "cartridge fork oil" and get smooth reliable action from my forks. it was recommended by Max (traxxion dynamics)

thick oil will not flow smoothly thru the valves resulting in a harsh ride.

KOokaloo!

Frank

[Pat Conlon]

Hey Frank, agreed. I was considering Golden Spectro 125/150 cartridge oil recommemded by GS for Kayaba cartridges.

Do you know how that compares to your 5w?

Pat,


A common misconception is that heavier fork oil for a heavier bike..... not true with cartridge forks.


the springs control the weight of the motorcycle   all the oil has to do is damp the motions of the spring.


in my FZ1 cartridge forks i run spectro 5wt "cartridge fork oil" and get smooth reliable action from my forks. it was recommended by Max (traxxion dynamics)

thick oil will not flow smoothly thru the valves resulting in a harsh ride.

KOokaloo!

Frank

[racerman_27410]

PAt,

the factory Yamaha fork oil "01" is equivalent to Spectro 125/150 or 7.5wt.

the 85/150 is = to 5wt..... which is what i use with 1.05kg springs.... if you are still running the stock valves then i would try a thinner oil than stock. IE the 85/150

i'm gonna see if i can round up the chart that mike at Spectro oils sent me showing comparative numbers from different brands of oils.... i have a feeling it was on a hard drive that crashed though.

KOokaloo!

[Pat Conlon]

Thanks Frank, that chart would be bitchen in our files....Pat