Buying a used outboard

[Unclebob]

Unclebob,

The smaller engine, I'd guess, would give you better fuel efficency.  To put it in VW terms, you can drive at 60 mph with both a bug and a Buick, but the bug will give far greater MPG.  

A bug and a buick are totally different vehicles, though. The Buick weighs a bunch more than a VW, and it has twice the cylinders.

I meant that it takes the same HP to move the same vehicle 50mph, regardless of HP. For example, my 2180cc (120hp) VW engine uses the same HP to push my buggy to 50mph as it would take a 1600cc (50hp) to do the same work. Yeah, the 2180cc could get there (and beyond) MUCH quicker if needed. If I keep my foot out of the firewall, fuel economy is about the same as a stocker.

What I'm getting at, is If I had a 90HP engine that I've got to keep at WOT to get on a plane -vs- a 200HP that gets there at half throttle, doesn't it all about equal out?


Ideally, I'd like to find an engine about 100-140hp, but with my measly budget, I'm trying to find an engine that's in the best shape for the least amount of money.

When a boat is rated for a given HP, is that because the transom can't handle more pushing power, or is it because of the weight? Or does it have something to do with the boats ability to stick to the water at speed? Maybe a combination of all 3?

[JimCt]

Unclebob,
Point taken re: bug & Buick.

Still, I'd still be concerned about overpowering the boat.  You might want to post a New Topic question about hull power rating and how the manufacturer determines it.

[Unclebob]

Good idea, Jim. That's something I've always wondered about.


For some reason the possibility of the engine falling off the transom gives me the heebie jeebies.

[JimCt]

Maybe this has been posted before, but a simple test to see if the transom is soft is to tilt the motor to it's full up position and have a helpful assistant push firmly up and down on the prop/skeg.  Standing at the side of the boat, eye-ball along the top edge of the transom.  If you see flex there, there may be a problem.

Another check might be to take a look around the outboard bracket & thru- bolt areas after the engine has been removed.  If you see squished-in compression areas and depression areas in the transom there's most likely soft wood in there.

When I bought my '73 17' a couple of weeks ago, I only did the up & down test and didn't see any problems.  But still, that transom wood's been encapsulated for 32 years... I'll take the motor off this fall and really go over it.

[Jerry-rigged]

I meant that it takes the same HP to move the same vehicle 50mph, regardless of HP. For example, my 2180cc (120hp) VW engine uses the same HP to push my buggy to 50mph as it would take a 1600cc (50hp) to do the same work. Yeah, the 2180cc could get there (and beyond) MUCH quicker if needed. If I keep my foot out of the firewall, fuel economy is about the same as a stocker.

It is diffacult to compare Cars and Boats when it comes to fuel effency.  Cars have gears, so ( hopefully)in you top gear, your engine is in it's 'sweet spot' (usally down in the RPM's) in terms of effency.

With boats, you prop (gear) the motor so it can wind out to top RPM.  After that, people usally just go, and don't pay attention to rpm much.  Big motors will use more gas at WOT, but if you start copmparing a set speed (like 30mph) with diffrent HP, the BIGGER motor will frequently win, because it is down in the rpm's, in it's sweet spot, where the smaller motor will be schreeming.  

I bet a 90hp would plane your boat just fine.  However if you are running 35 with the 115 (wot), you may only go 30 (WOT) or so with the 90.  If you are planning on running wide open all the itme, the 90 will use less gas.  If you throttle back the 115 to the same speed as the 90, it *should* get a bit better gas milage.

[JimCt]

Unclebob, anything new to report?

[Unclebob]

Not really. Been out of town in Texas for a week. I've lost a half-dozen or so E-bay auctions so far, but I think this is the route I'm gonna take to find an engine.

I was pleasantly surprised to find that shipping an engine won't break the bank.

There's also a lower unit on E-Bay right now that I'm watching that will fit my engine.

Going fishing in the morning with a friend who says they're pulling 60+ pound black drum out of the intracoastal, so that should give me a bit of incentive.

[JimCt]

If that eBay unit is in good shape that'll solve the problem a lot less expensively than another entire engine & controls & other rigging needed.

Have a great day fishing!  What's black drum?

[Unclebob]

Here's a nice Black Drum. Didn't know they got that big. The biggest I've ever pulled in was probably 10 pounds or so. Think I'll bring the heavy rod just in case. I imagine a 60+ pounder would put up a heck of a fight!

[Wilson]

We get those huge drums around the bridges here. Keith Knecht routinely uses them as shark bait.

[JimCt]

     HOLY CRAP!      

The hell with the fish... is that your wife????
Are they good eating? (the fish I mean...)

[Unclebob]

     HOLY CRAP!      

The hell with the fish... is that your wife????
Are they good eating? (the fish I mean...)

  Unfortunately, not my wife. That's not me, either, just a pic I found on the net.

Judging by this picture though, chicks dig guys that can catch big fish, even if their biceps are as big around as my wrists.

Didn't have any luck today. Only thing biting was catfish.

[JimCt]

That girl would kill the kid in that picture; maybe both of us too!  Great way to die though...

Aren't catfish supposed to be good eating?  The variety we get in this neck of the woods are pretty good.