Mercuiser 4.3L

[paul t b]

Hi guys
I am new here seeking advice
I have a Mercuiser 4.3L with Alfa 1 drive
In a invader 21
The engine is completely shot .

I have a chance of a FNM 110 HP turbo diesel
With Alamarin Waterjet System.
I think the weight to power Ratio would work
As the diesel and jet drive is a lot lighter
Than the mercuiser and drive
Any input would be very welcome
Thanks for looking

[tkeithlu]

Welcome to the forum, Paul.

That hot dog is a bit on the fringes of the forum's mandate, but some forum thinking applies.

There is a big problem with switching engines, and your proposed switch may be at the extreme. The hoses, control cables, and electrical connections go to different places on different engines. The through hulls match the former engine. Ditto the shaft location. Then, the designer left just the tiniest space the engine would fit in, because engine access does not sell boats at boat shows.

So, approach with caution. One successful switch described on the forum had the owner making a cardboard model of the new engine, just to see that it would fit. Don't let your eyeballs gloss over a problem, because you are going to spend a bunch of Saturdays solving stuff you didn't think existed.

[paul t b]

Hi Chris
Thanks for that
That’s why I thought I would get some advice
The swap I am proposing has everything with it the hole deal cables and switches dails the works

Paul

[Woodland Hills]

The quick and simple part is switching from gasoline to diesel. The hard part is converting the hull into a jet boat.
BTW, switching from gas to diesel is going to be a complicated pain in the ass. New fuel pump, new return lines to fuel tank, new motor mounts and controls, different steering, etc.

A couple of questions: how do you know the gas power package is heavier than the diesel and will your 21’ boat plane with only 1/2 the hp and a more inefficient drive type?

[paul t b]

Hi Woodward
Thanks for the reply
The mercuiser and drive is 370kg
The Fmn with jet drive is 216 kg
Trying to get as much feedback as possible to see which way to go
Paul