Is there a need for an aftermarket fuel pressure reg if your fitting a walbro 255 to a v2 classic ?

 

Not really, but, if you do make sure it's not a £30 ebay one.

 

Some say that the OE one can fail at the higher pressure developed by an aftermarket pump. Your OE FPR will be what? About two decades old?
But you probably don't need one. One benefit is that it will allow you to keep the pressure at the level you want as it will be adjustable. As above don't get a cheap one.

 

Thanks for the replies people much appreciated :-) what pressure would it be best set at ?

 

Mine is 3bar without vacuum attached at idle. With vac its about 2.6. Have a check around but I think that is normal.

You could fit a gauge before hand (you will need one to set the FPR anyway) see what is it with the OE one and then match it with the new one.