Repowering - engine size/weight?

[4cznskier]

I have a 1976 Marlin 18' ski boat with it's orginal Evinrude 115 that I am thinking about upgrading. In descending order of importance I am looking for;

*More power
*Oil inj.
*Lighter weight
*Better MPG
*Cleaner burning
*Quieter

I've been looking at early 90's era bass boats (like this http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=006&sspagename=STRK%3AMEWA%3AIT&viewitem=&item=160128850136&rd=1,1) to do an engine swap with for about $3000. They seem to commonly have a 115 V4 or a 150 V6 (don't want to go bigger than 150). I've been told that my '76 115 is actually only 90 horse so going to a newer 115 would be a significant increase in power. But as long as I am doing this why not go bigger - but V4's bigger than 115 seem to be not so common. I am just assuming that a newer generation 115 - 140 V4 would be a bit lighter and more fuel efficient than the gas hog that I have. I am wondering if maybe a 150 V6 might be as well?

Also - I am leaning towards OMC or Mercury and away from Force but don't have much of an opinion of Yamaha, Mariner, or others. Any info on weight comparisons (I've added a bit of weight to this boat over the years - SS ski pylon, bilge pump, battery charger, speakers, etc. and it would be nice to drop a few lbs. back off in the process) and any suggestions on anything in particular to look for or stay away from would greatly appreciated!

[Culprit]

New 115 E-TEC. (1st choice)
be careful buying used engines. Perform leakdown tests before thinking about buying. A lot of weak engines around. I don't think you will save any weight upgrading. v-4 is a v-4, the weights are quite close. a 115 from 86 up will have a lot more oomph than the old girl. Merc, mariner, evinrude johnson and yamaha are all good engines. I prefer the johnson, evinrude or yamaha over the mercs and mariners of that engine size. Don't waste your money on a Force, you are better off with what you have than downgrading to a force!

[K-Dawg]

1st, I agree that an E-tec is going to get better gas mileage. But, a Merc opti will be the same thing more or less. You could probable find a opti cheaper they have been out longer and odds of finding one used over a used E-tec are greater.
2nd, If you opt for one of these (E-tec or Optimax) you are way out of the 3000.00 dollar price range.
3rd, a Mariner is the same thing as the merc
4th, I prefer the Merc and Mariners over the others.
5th, Most all of the E-tec owners I have seen on here are extremmley happy with them. All though this could be due to the fact most are die hard omc guy's. Could be wrong though, just my 2 cents.

[captcarb]

A carbureted Johnson/Evinrude 150 or 175 from the early 90's to the early 2000's weighs 370. I am speaking of the 60 degree (eagle) motor prior to the cowl change that added weight. I have a 95 Faststrike which is that motor. It is one of the lightest V-6's around.

A 115 etec V-4 weighs the same.

jim

[Story]

This one would work great 1999 150 fitch evenrude got move it (http://forums.screamandfly.com/forums/showthread.php?t=132607). I have a 99, 200 Fitch. Lots of low end, great fuel mileage, and very quiet. Just a thought.

[David]

Johnnyrude weights are confusing.

cross flow V4 around 300 lb, ie yours
loop charge 90 degree V4, around 365 lb
cross flow 90 degree 150/175 V6, 381 lb
loop charge 60 degree V6, 150/175, 365 lb
Etec 115 369 lb
Etec 150 419 lb

Anything newer than 84 is propshaft rated.
Your motor is crank rated, which works out to about 10% less.

I would expect the loopers to burn less gas than the crossflows of equivalent HP. Any of the direct injected motors will burn a lot less gas than a carb motor

Merc V6s start at around 400 lb, and the Merc I4s are goofy, so if weight matters, stay with BRP/OMC or Yamaha.

An interesting choice would be a 90 HP TLDI Tohatsu, 315 lb. It is probably as powerful as your current motor and would burn way less gas.

I'd stay away from the Ficht era of OMC unless the price was very attractive.

[captcarb]

I think the 90 Yami carb weighs in at 270.

jim

[K-Dawg]

Had a buddy with a 90 yammie on his lil glassstream. It would haul the mail.

[4cznskier]

Hey guys - thanks for all the great info. Looks like a newer V4 actually weighs more than what I have but I can get a V6 that ways the same as a newer V4....? Oh well - I kinda like the idea of a 150 anyway! No more 140 4cyl.?

[David]

Yup, the 115 is the only V4 in the lineup now

[aaronmt73]

I think id go for a yamaha there reliable light wieght and chances are they havent been run as hard. I had a 85 marlin 18 with a 150 merc and a 200 merc now I have a yamaha and I canot see going back. Yamiies tend to be bought better used becoues alot of peolpe get caught up in the ,omoent they have to have the big black motor on the back. But ive been there over and over, I can say this yammies the only one that hasnt let me down somehow yet not saying others arent good just my experience. Aaron