Hi Nick,
just some info. for the other tossers looking in:
when bringing a bike into Malaysia unless tax examption is given. you will need to pay 30% excise duty and 30% import duty on bikes over 800cc.
for bikes purchased new in Malaysia a 10% Sales tax is also levied on new vehicles.
Malaysia has been slowly reducing import duties to come in line with trade agreements, now they are zero on ASEAN made vehicles, however to protect Proton they have increase excise tax on imports, at least from outside of asian.
The process to go through is below:-
1.A letter of application addressed to the Ministry Of International Trade and Industry (MITI) for the importing of a car from your home country to Malaysia for personal use.
2. A JK69 form must be purchased MITI and duly completed.
3. Documentation indicating proof of ownership. Typically this will be a purchase receipt or transfer of ownership/letter from the previous owner if the car was purchased second-hand.
4. The original and photocopied registration.
5. The cars original insurance documents and/or a letter from the insurance company.
6. Your work permit and letter of contract from your employer in Malaysia.
7. A photocopy of your passport.
Frankly if you are planing to come for many years, it may be worth the hassle, if you are here only for a couple of years, I'd just buy a local bike. there is a fair choice here. (less of a choice in East malaysia though, but still plenty of big traillies).
brother Dean 
