what do ya'll think about the Garmin 740s ? i have a 29ft scarab twin small blocks , planning to do a lot of poker runs in coastal area's and some lakes. Can i monitor engine data with this ? cant find any definite yes or no

You definitely can monitor engine data with the Garmin 740. Engine information needs to be interfaced properly to a NMEA 2000 backbone, constructed properly, which will transmit engine data to your 740 when the 740 is properly connected to the NMEA 2000 backbone as well.

May I recommend the brand new Garmin 741? It's a way better device, just released to the market.

West Marine has a two day sale on the 740s july 3 & 4th only $799 via instant gift card? it is slowly being fased out as the 70s and 741 is replacing it. 741 offers a chirp transducer capability which many of us do not need on the boats we run

If you want to monitor engine data engines manufactures do not output NMEA 2000. You will need some sort of gateway from them. If you have Mercury/Mercruiser and Smartcraft they sell a multiengine gateway.
However there has been a lot of issues with their gateways as of late causing problems on the NMEA 2000 backbone.

Great unit with with lots of features. I'm running 525s and purchased a Merc Monitor to take the engine digital buss info and convert it to NMEA 2000 so the Garmin can display the engine parameters. Nice having both digital and analog displays in case analog gauges indicate a problem you can double check on Garmin

Couple of questions.
What does the new 741 have that the 740 doesn't?

On the 740, i have older HP500EFI motors, is there anyway to convert that data to NEMA 2000?

http://bearbonesboating.com/products.html

Something like this. Several out there. Would have to talk to some people and determine best for your situation.

741 has faster updating speeds,and the touch screen has a pinch to zoom feature for starters