Yamaha TRX850 Enthusiasts Forum

I have a Japanese import 95 4nx.

wasnt planning on actually removing the legs from the bike so the "level down "method doesnt quite work. i have replaced leaking fork seals. BUT


Manuals I can find list the amount as 483 ml each leg. something sus here.

the fork legs fill to overflowing before i can get anywhere near 480ml.

Anybody have any idea where the discrepency is.


TIA
Tom R

i put about 950ml in mine (based on whats left in the 1ltr container of fork oil, so about 475ml in each leg.

The forks need to be extended when you fill them.


You would need to remove the fork legs to remove the old oil.........unless you turn the whole bike upside down. You probably have a load of old oil in there

took them apart so nothing left in them.

it is possible to replace seal without taking the leg out of the trees

Tom R

You need to remove each leg then turn them upside down pump them to actually make sure you empty all the oil still inside damper tubes and bottom of the legs. The other way to work out a level is to work on the air gap to the top of the fork. 140 /150 mm seems to be a favoured level by quite a few members looking on the search. I run 140 with emulators...

for crying out loud I took the slider of the stauncion.
There was no old oil left in it.
take the axle out, the bolt behind the axle, take out the seal retaining clip. pull down sharply on the slider and it is of in your hand. upturn it and there aint no old crap left

Tom R

When you add the fork oil you need to put in most of it in then pump the slider up and down slowly a number of times to allow the oil to work its way down to the bottom and get rid of any air.
Then add the rest of the oil and do some more pumping. If you pour it all in at once it probably will overflow.

As has been suggested, measure the air gap to fine-tune the oil level and to make sure both sides are the same. The air gap is measured with the spring out and the fork fully compressed.
Ideally this should be done with the forks vertical but you'll be able to be accurate enough with them on the bike.
Provided the level is in the ball park, the more important thing is that they're equal on both sides.

I have Race Tech springs and emulators and my air gap is 130mm

And dont forget to make sure you got all the old oil out first......

tomrux wrote:took them apart so nothing left in them.

it is possible to replace seal without taking the leg out of the trees

Tom R

yes, you pop it out using the existing oil. Fork off the bike and then compress it with a car jack in a doorway.....sooner or later the oil seal will pop