Repowering '73 MFG Niagara and had some questions.

[aarivers]

If you've seen my other posts you know a little about the boat and engine I have been dealing with. Well after getting the old Force 50 to fire up and run, it turns out it has a cracked cylinder and is pretty much just a parts motor.

So I'm now having to repower and need some advise. First off if I go to down to a 40hp from the 50hp, will I see a noticeable fuel savings, without losing much on the dig? I'm not real concerned about top speed.

Next is just trying to decide what motor, this is where I am having issues. I can't decide if the extra cost on the front end for a newer motor will be worth it in the long run. I'll give an example, I found a 2002 Honda 4 stroke EFI 50hp for $2500 on CL no pictures but sounds like a decent deal, then there's a 1999 2 stroke Johnson 50HP, also on CL, looks good, no power trim or tilt (old motor didn't have that stuff so not a deal breaker here) for $650. So would I save $1900 in headaches and fuel over say a 5 year period with the newer motor, or would the Johnson come out ahead?

Thanks for the help guys and gals.

 

[aarivers]

Re: Repowering '73 MFG Niagara and had some questions.

Bueller? Bueller?

 

[pckeen]

Re: Repowering '73 MFG Niagara and had some questions.

First off if I go to down to a 40hp from the 50hp, will I see a noticeable fuel savings, without losing much on the dig?

Not necessarily. By dropping the size of the motor, you force the smaller hp motor to work harder for the same speed, meaning there may be no gas savings. It's really hard to guess whether you would have a gas savings. If you went from a 70s 50hp to a modern 4 stroke 40 hp, you would see significant gas savings.

I repowered from a 70s 115hp to a nearly new Yamaha 90hp four stroke, the gas savings were dramatic (used less than half the previous amount), and I got better performance - no noticable difference in speed.

In repowering, you want to make sure that whatever you repower with is at least 70% of the maximum rated power for the boat - if you go less than that, you will suffer a loss of performance. If your boat is rated for a 50hp, I would think that you would be fine with a 40 hp motor.

Two other things to watch for - if you switch motor brands, you may find you have to replace controls and steering components - so check this before you buy. The two motors you are looking at will probably require new controls.

In terms of the two motors, I am a big fan of 4 strokes, so I would personally spend the extra $$ and go for the Honda. That motor has fuel injection, a much newer technology. The $650 price on the Johnson sounds really good, but my big questions is....why so cheap? If the seller has just repowered, he or she probably did that because the motor wasn't reliable. In buying a used motor, you are going to get what you pay for.

In terms of fuel savings - don't know enough about those two motors, but a 50hp fuel injected Honda has much newer technology and should be much more fuel efficient than a carburetted 2 stroke Johnson.