Thinking of making a switch

[DJ_Callahan_27]

As some of you may knowI own a 1988 19' Laser 3880 bass boat. It now has a Johnson GT 150 on it. The boat will flat out fly. Not sure of how fast that it will go (no gps as of now). On the lowrance x85 that I currently have on the boat it reads in the 90's. I know that the speed wheel type speedo's on this unit isn't accurate and not claiming that to be the true speed of the boat but the dash mounted speedo (also not at all accurate) quits at 65.

Anyway speed isn't the issue. Fuel consumption is. I'm wongering how small of a motor I could put on this boat and still get on plane easily and have a respectable topend speed alone with better fuel economy. Or would I be better off going with a newer motor of the same HP?

DJ

[Abbeysdad]

I'd think that boat should plane at 25mph - mine does and it's heavier I think.
Also, wouldn't yer fuel economy be better if you weren't going like a bat outta Heck?
Slow down and see what fuel economy you get.
I think my car could do 120 but I don't go much over 55 most of the time

[DJ_Callahan_27]

I don't run at WOT very often. I can get on plane and run pretty fast at about half throttle. even at that I still don't get very good fuel economy. My 84' Johnson GT 150 likes it fuel but it runs very strong. My boat has a 33 gal. tank and at WOT running from one spot to another I have to watch myself to keep from running out...lol. Some of the newer motors are claiming they get 5-6 MPG. I was thinking of hanging an E-tec on her (not new can't afford it). I have seen a few older E-tecs on ebay (not cheap but if it would extend my range on a tank of gas it may be worth it. I don't know just thinking aloud.

DJ

[ally260]

Don't think you would be happy with tha smaller motor. It will run with one but just not tha way some might think. Think it would hafta work to hard ta see much difference in fuel use. Donno know for sure though. A little 2.0 l50 Merc would be more of a gas miser and set up ta perform just as good as tha big Johnson...................JMO
From tha look in your picture I think ya might wanna work on tha "set up" of tha motor. it might help with performance and fuel use.
Looks like motor is way low and no set back. That boat likes about 8 inches of offset with tha motor as high as as you can get tha stock gearcase. Then ya gotta work with tha props ta find where it will perform at its best which will in turn make it a lot more efficent.
If it was a Merc I could pretty much get you dead on on the above but I can't even spell "OMC"
Maybe 1fast will show up ta give his suggestions 'bout tha (cough, cough) OMC. Think that boat with tha right stuff will run inta tha "honest" low seventy's. GL with it with whatever ya do...............

Did I mention that tha Laser is my favorite (almost more so than my ally).

[DJ_Callahan_27]

Ally, thanks for the info. I was going to put a jack plate on this boat. Had it but didn't realy want to drill any holes in the boats transom. I was going to buy one that would bolt up in the stock mounting holes for the motor but was told that it wasn't as strong. Don't know how much truth that there was to that, so I shyed away from it. By the time I decided agianst that jack plate I had already sold my other boat and the jack plate that I had went with it and honestly I just couldn't wait to get this boat on the water and try it out after 1fast and Zooker was telling me what they thought this boat should do.

I'm very happy with the performance of the boat as far as ride, fishablity, and even speed as is. The only down side is the fuel economy. And if I have to I can live with that. Just looking for ways to improve it.

Thanks again

DJ

[ally260]

Think if just tweak on your set up as ya go you can improve on its efficiency. Not drivin' with both feet on tha floor helps too
Set back (jack plates) shouldn't require ANY new holes in tha boat or motor. You will be surprised in tha difference in tha boat with one added. Something ya might wanna consider it its future.

Oh yeah, Did I mention I like Lasers. Glad you like yours ................T

[Captmikestarrett]

My Gambler 186 had a 175 White Johnson on it and was a beast on fuel. It was replaced with a 150 Johnson Fast Strike. The boat went faster and used less fuel.

Capt Mike

[Abbeysdad]

I think ally may be on to something - I'm no expert but it does look like there's way to much motor in the water perhaps creating drag.

[lilmule]

I had an 86 gt 150 on an 85 ranger 363 v,10 in rite hite jackplate and a foot throttle it got about 4- 4.5 mpg avg.Ran 59.3 mph at 5400 rpm on gps.The addition of the jackplate not only helps the boat in its preformance but also helps fuel consumption
The etec is great,at low throttle settings will certainly sip less fuel,but at wot virtually no difference.

[Bender]

I think the new EFI motors sure would make a big difference. I get about 2-2.5 MPG with an 07 Yamaha carbed motor and I think the EFIs in that range are supposed to get 4-5 MPG. Doesn't make much difference on little lakes, but running around here that difference is huge.
Maybe you can make a calculation based on how many miles you drive to see how much it would save or cost buying a new motor. Maybe it would justify the jackplate/rigging changes.

[MississippiBoy]

That was my first thought, too, Bender. DJ, if you buy a new motor and sell yours, divide the price difference by how much gas you save, and see where your break-even point is.
Say you're getting 2 mpg now, a new motor gets 4 mpg, and you have to pay $1000 more for it than you sell yours for. (I'm just making these numbers up, I've got no clue how much your motor might sell for.) You're saving 2 mpg, but how long will you have to keep the new motor for that 2 mpg to equal $1000?

[Bender]

I made a little spreadsheet just to figure out how much savings there are. You can download it here if you want: Here.
You can change the years, fuel cost, MPG, etc. and it should calculate the savings. Oil is based on 50:1.

It was just a quick thing, if you want more just let me know. Or maybe I should make this a web based app.


Figuring a new 150 will run around $10,000 it would take a long time to pay for the switch depending on how much you could get for a used motor.

[DJ_Callahan_27]

Bender, thanks for the spreedsheet. Yeah, I'm kinda leaning more toward keeping my motor. It may be hard on fuel but it still runs great and the more I think about it the more difficult it becomes justifing a newer motor.

However I would love to get mine to be alittle easier on the push water...lol...

DJ

[MississippiBoy]

Try this...take a couple good pictures of the mount holding the motor to the transom, especially which holes it's mounted in, how many are below and above it, etc. It might be too low, and if it is, Laser can probably tell you that for sure. It might be as simple as moving the motor up a little bit to get the lower unit a little higher in the water.

Laser will probably want to know the prop to pad measurements. Follow these instructions:
http://bbcboards.zeroforum.com/zerothread?id=65514 and post what you come up with, along with the pictures. That should give Laser or one of the other boat maniacs.....I mean enthusiasts.....some idea about whether or not moving the motor will do you any good.

[1FASTLASER]

Originally Posted by DJ_Callahan_27

Bender, thanks for the spreedsheet. Yeah, I'm kinda leaning more toward keeping my motor. It may be hard on fuel but it still runs great and the more I think about it the more difficult it becomes justifing a newer motor.

However I would love to get mine to be alittle easier on the push water...lol...

DJ

Hey DJ shoulda hollered at me bud. Ole alley gets the cookie today......The perfromance and fuel mileage will go up some when installing a Jackplate.

Before I go any further with an explanantion let mepoint out this though..the older GT and XP motors where NOT fuel misers.......trust me they liked the fuel..of course most of your older carbed V6 motors where the same.

No more holes need to be drilled to put a jp on.they have BIA mounting patterns and will bolt to exsisting holes.......DO NOT go anymore than a 8" plate ....preferably 6..Lasers dont like alot of setback but a 6" is a GREAT ADDITION.....you will accomplish 2 things......first the boat will plane better,run better AND get better fuel mileage........

Ole alley has had PLENTY of seat time in the Laser's..trust me he knows plenty on them fast lil demons..aint that right buddy.

Again I cant tell you exactly what you will gain as far as fuel mileage but I can assure you IT WILL GET BETTER.just remeber what I said about the carbed motors......One more thing and then I will shut upfer now....with the jackplate as far as running you can actually run faster at lower rpms which also translates into money in the pocket on fuel mileage.....I hope I have explained well enough

[DJ_Callahan_27]

Thanks guys I will keep my eyes open for a jp with 6" of setback and give it a try.
1fast, I know your right about the GT liking it fuel.

DJ