Yamaha EF2400iS and extended run fuel tanks

[cptxguys]

Hi,
I have a Yamaha EF2400iS. Got a great deal from Wise Sales. I used it this weekend in our 5er and it did great. I tested it with a 15,000 BTU A/C and it ran fine (but not much else, besides the battery inverter and the TV).

I'd like to use the Twin Tech option and parrallel two units. However, before I go that route, I'd like to determine if extended run tanks can be used on the Yamaha EF2400iS like they are on the Honda EU2000.

Anyone have any experience with external fuel tanks?

Thanks.