AJS & Matchless Owners Club

Hello. i have just bought a AJS JSM 50 and there is a problem with first gear. When i try to take of there is a grinding and the sprocket sorta jumps back and forth. every other gear is perfect. when i got the bike the clutch was not disengaging but i have fixed it now but has it been a case of the previous owner has just been jamming it into gear without the clutch. Looking for some help on the possible problem or if it is a common one with a quick fix.

Thanks.

I have just bought a 2014 AJS JSM and there is a grinding in first gear and it wont take of the line. it seems like the sprocket jumps back and forth. Any help would be great.

Thanks