so that me and my partner are confident enough in our relationship to get married
is it possible to apply for another visiotrs visa instead of fiance visa when his current one runs out
Yes
what is the likelihood of being granted another visitors visa after this one
If your partner still meets the Visitor's Immigration rules/requirements, the ECO will grant him another visitors Visa...however, if you think that you can do this Visitor business consecutively - such that your partner is 'hardly' in the home country - you will get caught out!!!
The visitors rules requirte that your partner meets the 'returnability' criteria..i.e
1). Has a secure/good job back home
2). Strong family, financial and economic ties with the home country.
Please not that if your partner stated that he was visiting you for 2 weeks and then spends 5months in the UK. The ECO may catch him out!!! when he applies for another visitor's Visa...especially at BHC's and ODP's were interviews for visitors Visas are required...
What is your Status in the UK? BC, ILR holder Student, Workpermit, Accenstry or WHM....????
Where there is a will there is a way.