How often to change gear oil?

[Zack Brappp44]

I have a 2001 kx125, I just put a new clutch in it and have about 4 hours on the bike. I am using bell ray full synthetic gear saver 80w. How often should I change it?

[turbo dan]

When shift quality degrades or when it looks dirty in the sight glass. 

Every 4-5 rides would be safe.

[mlatour]

Same here, my YZ125 get's it's gearbox oil (10W-30) replaced every 5 MX track days. 

 

Oil is cheap, gearbox parts are outrageously expensive.

[Zack Brappp44]

Same here, my YZ125 get's it's gearbox oil (10W-30) replaced every 5 MX track days. 
 
Oil is cheap, gearbox parts are outrageously expensive.

Ok, what is a good cheap oil that you recommend for my kx125?

[The Inquisitor]

I use Maxima 80WT in my tranny and change it every oil/filter change which is about 10 engine hours using an hour meter. I've got a 2005 CRF250R and still have the original clutch and IMO works as good as new.

I realize we have different bikes but regular maintenance with quality products will cost you less money in the long run

[mlatour]

Shell Rotella T4 (mineral) 15W-40 diesel engine oil.

 

It's JASO-MA rated so wet clutch safe and,

quite commonly used in both 4-stroke engine sumps and, separate gearbox sumps (many CRF's and 2-strokes)

Edited September 30, 2019 by mlatour

[Zack Brappp44]

I use Maxima 80WT in my tranny and change it every oil/filter change which is about 10 engine hours using an hour meter. I've got a 2005 CRF250R and still have the original clutch and IMO works as good as new.
I realize we have different bikes but regular maintenance with quality products will cost you less money in the long run

Ok, thanks. I’ll plan on doing about 10 hours. The bell ray full synthetic 80w should do the trick for every 10 hours.

[The Inquisitor]

4 minutes ago, Zack Brappp44 said:

Ok, thanks. I’ll plan on doing about 10 hours. The bell ray full synthetic 80w should do the trick for every 10 hours.

Ya it really depends on how/where you ride your bike but get an hour meter cus you could go out for an all day ride for an 8 hr ride but the bike might only be actually running for 3 hrs.

I'm sure the Bell Ray 80WT will be fine and IMO there is a reason why there is tranny oil for bikes hence why I use it on my bikes that that do not share engine/tranny. Different topic and a 4 stock dirt bike thing 

[KDXGarage]

Bel-Ray and Maxima are great!

 

One thing you can see in all the oil threads on the internet. No one is mad about the damage changing oil frequently causes. :-)