What size battery should i use as i have had 2 YTX7A-BS batterys now and both die if the bike stands for 2-3days

Is this battery big enough or should i check for somthing else or should i start testing the rec/reg and altenator

The bike is for road use not racing

Thats the right battery.

Check your charging system out.. your reg/rec is probably dead (very common) they either under-charge the battery so it goes flat (battery can be recharged and hopefully will be ok) or they over-charge the battery and kill it (battery is no good)

Check the charging system with a multimeter, it's not hard to do at all

Will do thx Neo

try this step by step guide to resolve any charging issues...
http://www.electrexworld.co.uk/pdfs/Tro ... G-&-RR.pdf

it should tell you where/if any problems are coming from

Thank you both for the info rec/reg was dead problem solved