Suzuki GSXR250 Oil

[DKay121]

Hi guys, I have just recently bought my first bike, a 1988 GSXR 250 GJ72A, that has a couple of little niggles but otherwise is pretty sweet (I do ride around with tools in my backpack though...).

I am about to flush the oil and change the filter, but I can't read my Japanese manual so I've no idea what weight of oil I should be putting into it? She's a little old and worn so I'm thinking thicker rather than thinner.

Cheers, Dom

[george formby]

This should be close enough, page 13. Google search (http://www.hnpl.net/~darcyw/GSX250/Suzuki_GSX250_Owner%27s_Manual_+_Wiring_Diagram.pd f)

Also..... JASO-MA (https://www.oilspecifications.org/articles/JASO_MA_JASO_MB.php)

I'm pretty sure JASO-MA is the standard you want.

[Hoonicorn]

If there are no oil leaks, i'd recommend a synthetic, definitely go for a motorcycle oil as they are different, or so I've been told, from car oils. Maybe look for something like https://www.repco.co.nz/en/brands/mobil/mobil-1-racing-4t-10w-40-4l/p/A1272391

[george formby]

If there are no oil leaks, i'd recommend a synthetic, definitely go for a motorcycle oil as they are different, or so I've been told, from car oils. Maybe look for something like https://www.repco.co.nz/en/brands/mobil/mobil-1-racing-4t-10w-40-4l/p/A1272391

:wait:I would think twice about going full synthetic. My 98 bike suffers clutch slip on the stuff. Fine on semi-synthetic or straight dinosaur oil.

I use any JASO-MA 10w-40 with no ill effects. Regular changing is probably the most important thing. I'm not exactly disagreeing with you Hoonicorn, just my experience on an older bike.

OP, you mentioned an engine flush....... May I suggest you just use a cheap bike oil rather than some kind of additive to achieve this. Warm engine, drop oil, replace with cheapo and heat the oil again, drop, change filter and fill up again. It will still shift a lot of spooge but not impact on hard seals and the like.

I started to do this with older engines after seeing some very mixed results from additives.

[AllanB]

10w40.

Motorcycle suitable.

I agree above regarding a flush avoid the car oil flushes - the bike runs a wet clutch in the same oil as the engine, the car engine flushes may not be suitable for your clutch.


The Castrol oil selector recommends 10w40. To be fair in the 80's and 90's all Japanese bikes ran on 10w40.

Supercheap and Repco frequently have specials on Penrite oils (I got 35% off for the car a couple weeks back for fancy POA Ester full synthetic). A number of their 'car' oils are suitable for motorcycles (it will state as much on the packet) and they also do motorcycle specific oil. Their on line oil selector confirms 10w40.

Of course any bike shop will sell you 10w40 motorcycle oil.

[Hoonicorn]

:wait:I would think twice about going full synthetic. My 98 bike suffers clutch slip on the stuff. Fine on semi-synthetic or straight dinosaur oil.

I use any JASO-MA 10w-40 with no ill effects. Regular changing is probably the most important thing. I'm not exactly disagreeing with you Hoonicorn, just my experience on an older bike.

OP, you mentioned an engine flush....... May I suggest you just use a cheap bike oil rather than some kind of additive to achieve this. Warm engine, drop oil, replace with cheapo and heat the oil again, drop, change filter and fill up again. It will still shift a lot of spooge but not impact on hard seals and the like.

I started to do this with older engines after seeing some very mixed results from additives.

OP might have done the oil change already, but that's all good advice there Formby. I suggested synthetic because a lot of them are formulated to help clean the engine and help improve performance on an old engine. However, I agree with your point on using a semi-synthetic, a new rider would not want the clutch slipping on them!

[DKay121]

Thanks for the advice everyone, I ended up going with 10w-40 Penrite fully-synthetic. I knew that the previous owner used fully-synthetic so I'll see how it goes.
I didn't do a flush in the end, and I'm not sure I want to change the oil filter again any time soon, I had to remove the exhaust to pull the cartridge out :facepalm: