I picked up a pair of FAST EZ EFI kits at a swap meet. I am contemplating trying it on a hp500 carb engine. My concern is water on the O2 sensor with the Gil exhaust. The risers are dry till the transom, but I have heard there is a fair amount of reversion with the Gil manifolds. I would weld in an O2 bung in the riser, right at the manifold / riser joint.

Has anyone used the FAST EFI system on a boat ?

Anyone want to swap a complete pair of Merc hp500 EFI for the new in the box FAST systems. I have two sets, complete with fuel pump kit and harness.

Follow this link it should help you with your project

http://www.ebay.com/itm/OXYGEN-SENSO...item2eb64afaf6


Cliff

I haven't used it on a boat, but I have 2 FAST easy efi throttle bodys mounted on 540 in a 67 Chevelle, Im going to fire it in the next week or 2 let you know how it works out....

Why not make two 1"alum spacers to go in between the manifold and the riser,tap out for your sensors.They is no water reversion at the bottom of the riser only up towards the end.I did it on eddie marines.JOHN SR

I make 2 and 3 inch spacers. The spacers are a easy way to add an oxygen sensor into the exhaust stream. A 1" spacer doesn't leave any room for a socket to put the sensor in, since the sensor socket size is 7/8".

How do you deal with the miss-alignment at the tail pipe caused by raising your riser pipe with a 2" spacer ?

There are various tubing bends available....the easiest is when we get to put transom exhaust in a virgin transom Generally it's not an issue with mandrel bent pieces available.

try to drill and tap the center of the intake manifold just below and inbetween the 2 center bolts,,you have a exhaust port their that is soppose to heat the intake cross over for the choke on a duel plane intake..or like suggested use a spacer with athe hole in it but under the turbulators...

We've run the Fast mpi in our boats for 15 years without a problem. I don't think the EZ would be a bad choice.

Mrfixxall:
That is a pretty clever idea. Unfortunately I have aftermarket heads W/O a crossover.

I am considering making an O2 bung and poping it through the riser pipe just above the manifold. I think I could TIG weld it inside and out. Anyone else try this ???