Been looking for cheap motorcycle oil and found these deals which meet or surpass the requirements for JASO MA (for motorcycles with a wet clutch). These deals are about $6-7/L for semi synthetic oil, whereas you can often pay up to $20/L.
- Nulon Semi-Synthetic High Performance Engine Oil 10W-40 5 Litre $31.88 (or also available for $31.88 on eBay and can be used with code C10 for 10% off transactions over $75)
- Nulon Semi-Synthetic Modern Everyday Engine Oil 15W-40 5 Litre $31.88
- Penrite Semi-Synthetic HPR Gas 10 Engine Oil 10W-50 5 Litre $37.99
- Castrol Activ 4T Motorcycle Oil 15W-50 4 Litre $30.49 [NOT semi-synthetic]
The HPR Gas is good stuff. Zinc rich, amazing TBN, and as you said wet clutch compatible.
I use it in all I can thanks to the TBN