I have a 1981 Seca (XJ750RH) which is in need of new exhaust system. I've met Seca owners who replaced the OEM 4 into 2 systems with MAC's 4 into 1 on their Secas and were quite happy. What I didn't think to ask them was whether or not they had to change the size of the carb jets and or adjust/balance the carbs.

If anyone has had any experience with this replacement/modification I'd appreciate hearing what you have to say. ie, Did you have to re-jet? Did you like the performance? How did it sound afterwards compared to the 4 into 2 etc?

Thanks in advance for any input.

John

I have the xj650 with 4-1 but it was on when i got it, jets are standard and has no flat spots. I think rejetting only becomes an issue if you fit pods aswell.