Fork oil change without removing fork - Honda CBR250R Forum : Honda CBR 250 Forums
User Tag List

 1Likes
Reply
 
LinkBack Thread Tools
post #1 of 15 Old 03-05-2019, 06:52 PM Thread Starter
Junior Member
 
Join Date: Jul 2015
Location: Australia
Posts: 25
Thanks: 0
Thanked 0 Times in 0 Posts
Fork oil change without removing fork

The manual procedure to change fork oil is to remove the whole fork, drain oil and pump fork to remove residual oil.

I stumbled across a method of just removing the fork cap bolt and sucking the oil out of the fork, then replacing the amount you removed.

The only downsides I can think of is it isn't a complete drain as you don't pump the forks (so probably 10% oil remains?) and you can't inspect the internals of the forks.

What do you guys think of this method? Is it a complete waste of time or an easy way to keep fork oil relatively fresh?

2012 Cbr250RA
cbrrider111 is offline  
Sponsored Links
Advertisement
 
post #2 of 15 Old 03-05-2019, 08:26 PM
Senior Member
 
Join Date: Sep 2011
Location: WI
Posts: 1,662
Thanks: 244
Thanked 258 Times in 197 Posts
Maybe not perfect, but the amount that's left isn't significant IMO. Better to have a higher quality fork oil of the proper weight (OEM oils are usually overly thin) mixed with a small amount of OEM oil than not changing it if pulling the forks is a no-go.

It's not going to hurt anything.

Make sure you are using Fork Oil, most likely 15W or close.
jkv357 is online now  
post #3 of 15 Old 03-05-2019, 08:35 PM Thread Starter
Junior Member
 
Join Date: Jul 2015
Location: Australia
Posts: 25
Thanks: 0
Thanked 0 Times in 0 Posts
So the factory recommended 10W is too thin? I was going to get Motul 10W fork oil.

2012 Cbr250RA
cbrrider111 is offline  
 
post #4 of 15 Old 03-06-2019, 07:01 PM
Senior Member
 
Join Date: Sep 2011
Location: WI
Posts: 1,662
Thanks: 244
Thanked 258 Times in 197 Posts
Quote:
Originally Posted by cbrrider111 View Post
So the factory recommended 10W is too thin? I was going to get Motul 10W fork oil.
Not sure, but most of the time suspension tuners seem to recommend 15W if you do any amount of "sport" riding.

20W seems more for the track unless you are running extra heavy springs due to rider weight.
jkv357 is online now  
post #5 of 15 Old 03-06-2019, 09:00 PM
Senior Member
 
CBR Blaize's Avatar
 
Join Date: Feb 2014
Location: New Hampshire
Posts: 123
Thanks: 2
Thanked 18 Times in 17 Posts
Garage
I would really recommend taking them off and apart completely. When I rebuilt my forks there were a good amount of metal dust at the bottom of the fork. If you just suck it out there is probably still gonna be a lot of metal left and that's going to keep causing wear. Now its probably not the end of the world but I would to prevent even more wearing of the bushings and fork tube.

I also upgraded to Motul 15W which definitely helped the damping a bit but not as much as I was hoping. I would look at the 20W.

2012 CBR250R Black
Mods:
Racetech springs and emulators, Yamaha R6 shock, Yoshi Rearset Risers, Babyface GP Shift adapter, EBC HH Sintered Front and Rear Brake Pads, CBR600RR pegs, Mirror delete with CBR600RR block offs, Ebay Bar-end mirror, Red LED dash, The2Wheels levers, Homemade Fender Eliminator, LED Blinkers, Tank pads and grips, CBR300R seat, Spider Peak red Grips, Vortex Clip ons, DFC, Delkevic 14' Slip on, Spiegler Braided Front Brake Line,Black Rims
Soon to be mods:
Big Bore?
CBR Blaize is offline  
post #6 of 15 Old 03-07-2019, 08:27 AM
Junior Member
 
JimW337's Avatar
 
Join Date: Oct 2012
Posts: 26
Thanks: 0
Thanked 7 Times in 5 Posts
I was just at the Honda dealer picking up an oil filter and asked about fork oil. They said the stock fork oil is 5W and if I wanted to go higher they recommended 7.5W.


Now I'm going to have to go do a little reading in the factory manual.

JimW
Greensboro, NC
JimW337 is online now  
post #7 of 15 Old 03-07-2019, 09:23 AM
Senior Member
 
Join Date: Sep 2011
Location: WI
Posts: 1,662
Thanks: 244
Thanked 258 Times in 197 Posts
Quote:
Originally Posted by CBR Blaize View Post
I would really recommend taking them off and apart completely. When I rebuilt my forks there were a good amount of metal dust at the bottom of the fork. If you just suck it out there is probably still gonna be a lot of metal left and that's going to keep causing wear. Now its probably not the end of the world but I would to prevent even more wearing of the bushings and fork tube.

I also upgraded to Motul 15W which definitely helped the damping a bit but not as much as I was hoping. I would look at the 20W.
Depending on the age and mileage, there may be some gunk sitting in the bottom of the forks. Removing and flushing them out is the best if possible.

For fork oil weight it's going to depend on your riding style and weight. Many mid-range bikes have very weak fork springs, and can benefit from proper rate springs for your size and riding style. My SV650 had notoriously weak fork springs, and replacing them with the proper rate springs and correct fork oil made a big difference. I also swapped the junk rear shock for a correct Ohlins unit as well. Stock suspension is usually barely adequate for anything except moderate riding, so if you like to ride a little quicker it's worth looking into better options.

As far as the oil, search around and see what people are using. Sonic Springs has a calculator on their site that tells the original spring rates of numerous cycles and can calculate the optimum rate for you. They may also be able to recommend the correct weight for oil. You can also check what racers are using, and step down a notch from there.
jkv357 is online now  
post #8 of 15 Old 03-07-2019, 03:49 PM
Junior Member
 
Join Date: Sep 2018
Location: Anglesey, UK.
Posts: 18
Thanks: 0
Thanked 2 Times in 2 Posts
I would never change fork oil without removing forks in order to completely drain the old oil. It is surprising how much residue from wear is in the oil. This needs cleaning out. The muck you see is metal dust and oil seal dust - not good to have in your clean, new oil.
Gromit2 is online now  
post #9 of 15 Old 03-13-2019, 07:39 PM Thread Starter
Junior Member
 
Join Date: Jul 2015
Location: Australia
Posts: 25
Thanks: 0
Thanked 0 Times in 0 Posts
I end up just doing the suck out method, and pulled out this terrible metallic black solution. I then put back the same amount of fresh oil. Next time I may take the forks off, or if the seals need replacing.

Still way better than leaving the old oil in.

(New oil is on the left)
Attached Images
File Type: jpg IMG_0869.JPG (84.0 KB, 10 views)

2012 Cbr250RA
cbrrider111 is offline  
post #10 of 15 Old 03-14-2019, 10:01 AM
Senior Member
 
Join Date: Sep 2011
Location: WI
Posts: 1,662
Thanks: 244
Thanked 258 Times in 197 Posts
Not perfect, but an improvement no doubt.

You could do another quick change again next season. I'd pump the forks numerous times to mix the contaminants before siphoning.

Not a big project, and fork oil in those amounts is reasonably inexpensive.
jkv357 is online now  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Honda CBR250R Forum : Honda CBR 250 Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome