Problems with madeira thread

Aloha,
Have any of you guys been having problems with Madeira POLY? Specially with BLACK AND WHITE and recently with GREEN 1988. The thread seems to be thinner than 40 what gives us a lot of trouble with tension. One of our machines is the 4 head brother 1240bc and it is really having a hard time to handle that. Any inputs or had anybody gone through that? Thanks

Location: 
United States

Robert Young wrote:
haven't noticed much difference but then again we keep black on one needle and white on one needle ALL THE TIME... so those specific upper tensions seem to be enough to balance anything else on the machine.

Thanks for answering back Robert. Black and white are also untouchables here. I have just switched to black Isacord today and it worked really nice! I hope I won't need to switch them all.