Vintage Dirt Bike Q & A

This has probably been beaten to death but here it goes...
I have had this bike for a couple weeks and it has occurred to me the oil should be changed... hmmm.

What is the consensus on oil to use, and frequency to change it?

Or, direct me to a thread that will answer my question... Thanks!!

Dave

Personally, I use Castrol 20w-50 @ the Manufacturers' suggested level. I change it after every ride/race. Others like to use the 80w or 90w gear oil.

The local dealer recommends 85 wt gear oil, Honda brand of course at $6.00 per quart...
Not that it would break my bank but I figured an off the shelf alternative must be avail, like the Castrol 20w50.... That's what I'll stop and buy on my ride home today..Thanks!

My grandson has a KX65 and I think I'll use the same oil in it too..

Most manufacturers will recommend the heavier weight gear oil. As often as I change it, after every ride, $1.25 is a lot better than $6, and I have yet to see any differences in wear. The KX65 will be fine with the 20w-50 too.

20w-50 is a little thicker than 85 wt gear oil. Either is fine for your transmission.

i use ATF

_________________
80 CR250Ra
80 CR250Ra
78 CR250R
80 CR80
82 Bultaco Sherpa 340
78 Bultaco Pursang 250 MK12
76 Bultaco Frontera 370 MK10
76 Bultaco Alpina 250
73 Bultaco Lobito 125 MK6
76 Suzuki RM125A
90 Kawasaki KX250

ATF as in Automatic Transmission Fluid?
Seems the opposite extreme as far as viscosity goes. What if any are the advantages or disadvantages of this choice? How does ATF affect the clutch?
I've changed the 250 oil twice with 20-50. The first drain was nasty looking so I changed it again after a couple hours riding. I'll keep it clean from now on...

Thanks for the replies! Keep'in me educated on my new toy...
http://borgpics.ulmb.com/2008-8-14%20Motorcycles/index.html

Dave

I've heard that one before (using ATF in the tranny), but I have never tried it myself. I don't see the benefits of using an "automatic" type fluid in a "manual" 4, 5 or 6 speed transmission. Maybe I'm missing something....... All I can go by is what I have tried and still use, 20w50 Castrol. I have used it in every MX bike I have ever owned (including my '82 CR250R), and have never had a clutch related failure and the plates seem to last quite a while. If it ain't broke, don't fix it......

yes, ATF. many riders here in germany use it in their 2t-transmissions. no matter if the bike is old or new.
it is a hi quality gear oil and it is designd for good clutch function.
the viscosity is not so important for transmissions.
if you use motoroil in your gear, you have to use motorcicleoil.
caroil is not made for gears!
the lighter atf oil makes the cold engine easyer to turn and the clutch doesn´t glue when the ride beginns.

_________________
80 CR250Ra
80 CR250Ra
78 CR250R
80 CR80
82 Bultaco Sherpa 340
78 Bultaco Pursang 250 MK12
76 Bultaco Frontera 370 MK10
76 Bultaco Alpina 250
73 Bultaco Lobito 125 MK6
76 Suzuki RM125A
90 Kawasaki KX250

I have noticed the clutch grabs when I first shift into gear cold. My grandsons 65 is doing the same thing and I have used Castrol 20-50 in both.
What would be the major difference between "Gear Oil" and the Castrol motor oil? Would the clutch continue to behave this way if we were to use motorcicleoil?

How often do you change the ATF in your gearcase? Would there be any adverse effect in changing to ATF now that I have used motor oil?
Dave

I thought that atf would be to light of an oil to use am I wrong?

is your castrol 20-50 made for cars or motorbikes?
car motoroil is made only for engines.
motorbike motoroil is made for engine and transmission.
the caroil has no additives to prevent the gears cutting the oils molecularcompound. the oil gets faster old, it looeses the weight spezification, it gets thinner.
gear lubrication is different to engine lubrication, the oil has to endure higher pressure between the teeth of the gears that a carengineoil can´t do.

i change oil once in a year, that´s about 50hours running time. don´t know if it is necessary, it belongs to my yearly service.

you will not get any adverse effect if you change.

_________________
80 CR250Ra
80 CR250Ra
78 CR250R
80 CR80
82 Bultaco Sherpa 340
78 Bultaco Pursang 250 MK12
76 Bultaco Frontera 370 MK10
76 Bultaco Alpina 250
73 Bultaco Lobito 125 MK6
76 Suzuki RM125A
90 Kawasaki KX250

you are wrong

_________________
80 CR250Ra
80 CR250Ra
78 CR250R
80 CR80
82 Bultaco Sherpa 340
78 Bultaco Pursang 250 MK12
76 Bultaco Frontera 370 MK10
76 Bultaco Alpina 250
73 Bultaco Lobito 125 MK6
76 Suzuki RM125A
90 Kawasaki KX250

Ha ha ha yeah not suprising I usally am.

_________________
80 CR250Ra
80 CR250Ra
78 CR250R
80 CR80
82 Bultaco Sherpa 340
78 Bultaco Pursang 250 MK12
76 Bultaco Frontera 370 MK10
76 Bultaco Alpina 250
73 Bultaco Lobito 125 MK6
76 Suzuki RM125A
90 Kawasaki KX250