Hi Master..I got 1 Suzuki GS450.I think the year make around 1981-1984 model.so i like to know from you master about the fork oil measurement and what the best oil brand to use.thx

The amount of oil that goes in the forks of a 1982 Suzuki GS 750T will depend on the type of forks that are installed on the motorcycle. It is important to use the correct amount of oil to ensure that the forks are functioning properly.
If your Suzuki GS 750T has standard telescopic forks, you will need to add 10.8 ounces (320 mL) of fork oil to each fork. If your motorcycle has air-assisted forks, you will need to consult the owner's manual to determine the correct amount of oil to use.
To add oil to the forks, you will need to remove the fork caps and use a fork oil level gauge or a piece of wire to measure the amount of oil in the forks. If the oil level is too low, add oil until the forks are filled to the correct level. If the oil level is too high, remove excess oil until the forks are at the correct level.
I hope this information helps! Let me know if you have any other questions.

Question edited for clarity.

RM85 Fork Specs. Bound to be the same forks

When adjusting the fork oil level, compress the outer tube fully
without the fork spring.
? 09943-74111: Front fork oil level gauge
? Fork oil level (Standard): 124 mm (4.88 in)
? 99000-99001-SS5:SUZUKI FORK OIL SS-05
? Standard fork oil capacity (each leg): 351 ml
or an equivalent fork oil
(11.86/12.36 US/lmp oz

Free Service manual for the RM85

https://www.manualslib.com/manual/824675/Suzuki-Rm85.html?page=164&term=fork+oil&selected=1#manual

Lots of Service Manuals for around $34

https://www.ebay.com/itm/385931112664?hash=item59db4970d8:g:WyUAAOSwkFpj2-n~

More here.

https://www.google.com/search?q=1986+suzuki+rm80+service+manual

..

Drain the fluid and measure it, the drain plugs are at the bottom of the forks leg, then unscrew the cap at top fork tube and install the same amount of fork oil as drained out.

Hi,
You need to check that you are actually getting the full length of stroke from the master cylinder.
If you are then you still a captive air pocket in the master cylinder and the only way to get rid of it is to vacum bleed the system from the master cylinder to the slave cylinder.
Check these and let me know, I can give you further information.
Thanks
Jason

Hi, all model VS 800 from1992-2000 take the same amount of oil in the front forks, using 10 weight fork oil measure into a clean measuring device or mark the side of the oil bottle 413 mls, pour this caerfully into 1 fork, and the same amount into the other fork, 413/413 cm (3)

HI, IF YOU DONT KNOW THE MACHINES HISTORY, AS THE BIKE IS NOW 4 YEARS OLD IT WOULD NOT HURT TO GIVE IT A THOROUGH CHECK OVER , IN GENERAL THESE K5-K6 ARE A GOOD BIKE. I WOULD BE THINKING OF CHANGING/ FORK OIL,/ BRAKE FLUIDS IN ADDITION TO ANY OTHER WORK, MANY OVERLOOKED ITEMS SUCH AS SPROCKET HOUSING BEARINGS/ REAR SUSPENSION BEARINGS/ WHEEL SPINDLES WOULD ALL BENEFIT FROM REMOVAL INSPECTION AND RE LUBRICATING. ANY FURTHER HELP FEEL FREE TO ASK

110mm oil height in each fork tube. Remember to bleed it first to ensure all air is out the inner chamber and then measure 110mm from the top of the tube, fully compressed with no spring or damping rod inside. USe a 5W fork oil. You can also look at WWW.RACETECH.com under search, and then valving search, enter all your relevant details and bike model and it calculates it for you.

Remove the small plugs at the bottom of each fork slider and drain the forks. Do this by working the forks up and down until the forks are empty. Then, refill the forks with the proper amount of oil. Since you are not disassembling the forks and cleaning them out, you should use the "wet" measure of oil instead of the "dry" measurement.

Since you didn't tell me exactly what year model 883 you have, if the fork tubes are 39mm tubes (measure the top tube) use the following amount of oil. I use 30 wt. fork oil. If this is too stiff, drop down to 20 weight.

883 Hugger --- 10.7 ounces
all others --- 9.0 ounces

That's the only ones I have information for at this time.

Go to cycle gear and get the fork oil measurer. it will cost minimal and you can measure 1 fork. mark it then do your work, after that just fill to the level that you removed. recomend olins oil. costly but great. about $40 a bottle. 1 bottle will do both

you should be able to get a rebuild kit from m&p in swansea.try them on line to check or try robinsons foundries they run an ad in the mcn