fork oil recommendation

I want to change the fork oil in my 83 KZ750 LTD Shaft. The manual calls for 5W20 fork Oil. I went to the dealer and he said to use 10W fork oil. Now the springs feel mushy. Should I go with 20W fork oil? What is 5W20 fork oil equivalent to in a strait weight oil?

Could try ATF for a stiffer ride. Be sure volume is correct per FSM and equal in both sides. Am thinking ATF is roughly equivalent to 20 weight.

Good Luck!

jon0108 wrote:

I want to change the fork oil in my 83 KZ750 LTD Shaft. The manual calls for 5W20 fork Oil. I went to the dealer and he said to use 10W fork oil. Now the springs feel mushy. Should I go with 20W fork oil? What is 5W20 fork oil equivalent to in a strait weight oil?

I used to know that a long time ago. I do remember I thought my forks were a bit soft and so I mixed some 30W motor oil about 50-50 into the fork oil and they got stiff enough to loosen my teeth.

Fork oil is a different kind of oil, I don't recommend using straight motor oil. They put seal conditioners and detergents in the fork oil as I recall.

One posted opinion:

Tried 10wt first - nice on pavement, too soft in the woods. Have 20wt in it now - a little harsh on pavement, but great off-road. I'd suggest trying to find some 15wt to start with if I were you. Not all the shops around here had it, but I did find it after stopping a couple places.

reference:

QUESTION FOUR: IS FORK OIL MEASURED BY THE SAE SCALE?


No. Fork oil weights are derived from the industrial standards used for hydraulic applications, called the Saybolt Seconds Universal (SSU). This measurement uses a similar viscometer arrangement as used to determine a cSt value, but grades the oil using a much more sensitive viscosity calibration scale.

www.motocrossactionmag.com/ME2/dirmod.as...40CF833A439ACD16632F

You should try Bel-Ray 15W Fork Oil. I've been using it for MANY years (changing it every 2 years) with excellent results. Ed

thanks. I'll go with the 15w. I have belray 10w in it now, i guess its to light.

I use Belray 20 wt. However, it is hot in Texas and I wiegh 250 lbs...chris3

2 or 3 seasoned Kawi riders have told me to use a 30 weight oil in the forks.
I'm still looking for some, but will use the highest number (up to 30) I can find next time.

jon0108 wrote:

thanks. I'll go with the 15w. I have belray 10w in it now, i guess its to light.

Just checked mine and was surprised to see it is PJ-1 20 "medium" fork oil, I thought I was running something lighter. It seems just right for street riding, I only weigh 165.

rstnick wrote:

2 or 3 seasoned Kawi riders have told me to use a 30 weight oil in the forks.
I'm still looking for some, but will use the highest number (up to 30) I can find next time.

30W fork oil here:

www.jpcycles.com/productgroup.aspx?GID=4...56-A628-5B453572125C



Or, the Bel-Ray brand that costs twice as much:

www.jpcycles.com/productgroup.aspx?GID=1...E7-9840-8F53A22012A7

I ended up going with the BelRay 20WT. Fork OIl. What a difference. Much,much better than the 10 WT.oil.