Vintage Dirt Bike Q & A

Hi guys what is the actual proper weight of oil a guy should use in the transmission of a 78 cr250? In hot climate...

Thanks in advance...

i´m using ATF for about 20 years now at all 2T trannies.

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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

SAE 80w motorcycle gear oil.

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Michael Stiles
1979 Honda CR250R Elsinore | 2006 Husqvarna SM510R | 2007 Service Honda CR500R-AF

haha ok you guys are at totally different ends of the rainbow here!!! One is using ATF the other is using 80W gear oil?? I have been using straight 30W but was thinking of switching... maybe i should hold a poll of what everyone else uses.... not whats 'proper'....

no, both are gearoils.
ATF is special designed for gears and clutches.
one advantage is perfect clutchwork when oil is cold.
you can also use 10w-40 (or for hot climate 20w-50) MOTORCYCLE engine oil.

choose what you prefer.
don´t use truck or car gear oil.

_________________
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

Ok I was thinking 80w automotive differential oil when i read it, and I always thought atf was way too thin but hey if you guys use it then obviously its not!! I will likely try the 20w50. Thanks

Also... Iv always just guessed on the amount but whats the proper amount to put in?

Thanks

_________________
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

that´s the advantage, you need less power to turn the transmission with the thinner oil.

_________________
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

Would a guy notice a difference in power if he switched to atf or is that unlikely? Also I never knew about the oil check bolt... i always just looked through the filler hole and guessed... cool... are all bikes like this or just the red racers?