Just got my STS .28 in my MTA4. First couple of pulls it fired up just like my sts.12r3 did. I ran 4 tanks through it on idle (man its loud my ears are still ringing) I gave it another 4 tanks running it round on 1/4 to 1/2 throttle. I then went to give it a bit more and as soon as you go past around 2/3 throttle it splutters and stops revving, it does not cut out it just lets you think its gonna. I gave it another 4 tanks going round on 1/4 to 1/2 throttle which is incredibly boring just to see if it would have to be broken in more but when i tried again it just does the same. I tried to lean it off a little on the HSN to see if it was overly rich from factory and thats done nothing at all. Any Ideas??

Cheers

Matt