Front Fork oil adjustment help

[rmracer]

Hello,

After completing several problems on my 98 rm 80, I am ready to move on to the next one. My front shocks seem like they have no oil in them :yikes: , at least my dad says. You can compress the forks all the way almost when you bounce up and down on the bike. That doesn't seem right to me. It should have more of a spring feeling I believe :think: . My question is how do I add oil into the forks? The only way my manual tells me how is to take the forks totally apart and I don't want to do that! Can you drop oil down the air bleed hole at the top of the fork while the fork is compressed? Also, how do I measure the oil level currently in there? I really don't want to buy a tool just for that. I appreciate any input. Thanks :worship:

 

[wornknobby]

well first get the bike off the ground so that the front wheel isn't touching, then bleed the air out of the forks. if you ar 100% positive that there is oil in the forks and that it is the same level in each then you can just remove the big cap screw on the top of the forks and pour some fork oil in with a funnel. just make sure you put the same amount in each fork.

 

[i_955]

You have to take the forks out of the bike.
Well you don't have to but "you" have to.
Not knowing what is in there you must remove the springs to get the same amount in each fork.
If you had just finished a complete service on your forks "then" ya, you could just add some.

Like your manual states, the springs must be removed and tubes compressed. Then pour oil in and suck out extra.

I used a $1.00 syringe with a tube stuffed in the end. Might be $2.00 including tax. measure the height on the tube and put some tape around the tube. This must be measured before the tube gets near oil or the tape won't stay put.

5 weight fork oil would most likely be what to buy. If your bike shops are anything like mine around her be careful, all they stock is Harley Davidson 20 weight. It is no good in your bike unless you weigh 7 to 800lbs..

 

[rmracer]

Update

This morning I took the caps off per what wornknobby said. I took the spring out ( I was amazed I was able to go this far since I had no idea what I was doing) :coocoo: and compressed the forks like the manual said. Now, my question is how do I measure the oil level ? The oil that is in there (very little i may add) is a dirty grayish color :ohmy: . I think I may have to replace the oil. I don't really want to take all the seals out and "tear" apart the fork since my seals are fine and everything. So, should I just take the forks off the bike, empty them upside down and refill them with the recommended amount? :think:
Thanks. I hope you can guide me through this. :ugg:

 

[wornknobby]

yes you could do that, but that will never get all of the old dirty oil out and what is left in there could contaiminate your "new" oil. if you where to do that, i would take as much of the fork apart as possible and clean every thing. What i did was completly removed every thing and cleaned every part in there. then i washed the tubes out to make sure they were nice and clean for a while. :) but if you don't want to remove the seals, (i don't blame you :bang: ) then remove as mouch as possible and just fill with the recomended amout.

i know many dissagree with this procedure, but it has worked for me for years and no problems since: use a measuring bottle with accurate hatch marks , then fill bottle to get recommended amount of oil and just pour slowley down the forks. then slowly work the for to distribute the oil,, make sure you oil the upper parts of your forks as they will not be in the "bath". i know my forks say standard is 21 ounces.

 

[rmracer]

I plan on filling my forks sometime tonight. My question is that my dad has some old Bel Ray SAE 20 ( 20 weight ? ). I was wondering if this would work since my manual recommends 10 weight, not anything else. Could I maybe mix some 5 or 10 weight motor oil with it to bring the viscosity down? My weight is 120 lbs. Thanks

 

[nickyd]

this is the absolute scariest thread I have ever read. dude, take the forks to the shop and let them do it...people are telling you the RIGHT way to do this, which with patience and a manual is not impossible. you keep on suggesting shortcut ways to rig up your forks, like mixing oil and using 20 weight.....get the right oil. get the right tools and get it done...as was mentioned earlier if you don't get the old oil out, your new oil will be contaminated and your seals will go. you can just about the whole fork apart without touching the seals.

 

[Flyboy500]

You had better rebuild your forks! New Dust Seals,Oil Seals,Slider Bushings and Guide Bushings need replaced! If you didn't have leaking seals you wouldn't be low on oil! Really not a tough job if you get a service book... When rebuilding remember to keep everything clean! Really the only special tool you need is a oil seal driver, you can even make one with PVC pipe... I can rebuild each fork in 15-20 minutes. Learn to do repairs the right way or pay later... Try to use the "search option" on this page... Rebuilding front forks :cool: If you put fresh oil in forks you'll notice oil on the floor soon... Yep, bad seals!

 

[i_955]

RMRACER,
We understand that you are trying to get an old bike running for little to no cost but some things must be done right. Two that come to mind are brakes and suspension, and everything else for that matter.

Please get the Haynes manual, it explains things much clearer than the factory manual.
Get some Kerosene and a hand pump spray bottle, it is the parts cleaner for everything.

You are in a tough spot, your dad sounds like he has some backyard mechanical experience and the boys here are in the know. You are stuck in the middle between the man you must respect and sounds like he is behind you, and some guys on the net. Fortunately for you, we can ease the frequency that things are going to fail with the bandage maintenance practices your dad appears to favour over a couple bucks.

The reason I'm saying this is, yes you can use engine oil in your forks. BUT, it is only in a pinch, until you can get the correct oil and do a proper "long term" job with the proper tools/lubes/nuts/bolts.

I've seen some bad things happen last season both on the trails and at the track because of mechanical neglect.

There is great info in this thread and on this site. "nickyd" sums it up nice, "search" on whatever topic you and our dad are ready to tackle and have fun doing it together.