Any experience with Mercury 3.0 TKS with alpha sterndrive?

[Dale R. Hamilton]

Some of you guys know I've been powering my mahogany runabouts with Mercury's Vazar sterndrive. This is a wonderful opposed 4 boxer style engine that is perfect form my needs. Unfortunately it is no longer available. Mercury make a somewhat larger 4 cylinder 3.0 called the TKS that will fit, and its 135 hp instead of 100- always a good thing. Any experience guys?

[Breakaway]

Dale--I believe that motor is discontinued, or soon to be, due to emissions regs. Might not matter as an individual powering or repowering a boat, but as a builder, it may be a concern.

I have run this motor in a lot of small boats. Its reliable, dead simple, fuel-spark-air type motor. At one point there was an issue with the carburetors starving for fuel in high speed/banked turns. But that was some time ago.

Kevin

[mcdenny]

Very heavy (for the power) and not very fuel efficient. It's design roots are way back in the 1960s when GM developed it for the "new" small cars like Chevy II.

I imagine the esthetics of an outboard make that not an option. How about a straight shaft inboard with a marinized modern 4 cyl engine?

[Dale R. Hamilton]

Denny- I did that with a Subaru. Too much custom blacksmithing. I need a drop in marine engine/drive.

[gstanfield]

As mentioned they are a bit heavy for the amount of power, but the flipside to that is the fact that being overbuilt means they are rock solid dependable and long lasting. I know of a few that should have worn out years ago and yet they are still going. I kinda like an overbuilt powerplant myself.

[mcdenny]

How about a Mercruiser jet drive:


Its a V6 200 hp Optimax outboard power head mated to a jet drive. 370 pounds weight would be OK for your boat and much better than the 600 ish pound weight of the 3.0 outdrive; 200hp would be way too much (perfect!). No idea of cost.

I'd also try to find a late model 4 stroke personal watercraft. If it had a wrecked hull so much the better. You would get a perfect power plant for your boat with all controls, gages, gas tank, etc. I just looked up the smallest 4 stroke Kawasaki for a reference point. It is 1.5 liter 4 stroke, digital fuel injection, 160 hp.