I have a 98 Honda foreman. Bought mine running. Got it running but when engaging into first gear it dies. Any feedback would be great. Could the carb cause this or what else.

 

When engaging first, nothing should happen as the engine doesn't take up the drive until you rev it. If it does stall "when engaging into first" check if the centrifugal clutch is seized, or the one way clutch fitted backwards. Engine off, engage 1st gear, push bike backwards, it should roll fairly freely. Roll bike forwards, it should be very difficult, and be trying to turn engine over. If it won't roll either way the centrifugal or one way clutch is stuck. If it does the opposite to what it should do, the one way is in backwards. If the clutches are OK, 450 Hondas have a wire from neutral light to CDI to give a better spark when in neutral, if the main CDI earth has come off it could be taking it's earth from the neutral light wire, which is switched off when you engage a gear. On 400s this CDI wire only works during starting, so can't cause your problem on 400s.