1981 Motor Boating Magazine v20 with Merc 200hp

[bgreene]

Interesting info as usual from our assorted group.

I just don't want our V guys with 150 hp to start feeling bad !

My " enormous" 3.3 liter, 200hp HO Etec..........still only runs the V21 to 49+/- mph, so is no faster than the old, light mercury 200.


I bet you're correct THERM, today's DFI 150 likely more fuel efficient than 200 DFI.

[THEFERMANATOR]

DFI's equalled the field out so it brought you down closer to the 1 GPH per 11-13HP across the RPM range. The old rule of thumb for carbed 2 strokes was they would burn 1 GPH for every 10HP they put out. My 140 burned right around 13-15 GPH, my 225 was around 23-25(but it was putting out closer to 250 with porting, so right on track for the 1=10 rule). At cruise you used to go to the north side of this number, but many engines were ALOT higher. DFI's and 4 strokes maintain this balance across the RPM band pretty linearly. So if a hull takes say 120HP to run at 30MPH, a 150/175/200 will all be pretty close to 10GPH fuel burn. I know that with lean burn engines nowadays, they are doing even better than the 1=12 rule.

[bigshrimpin]

as ferm mentioned in 1981 the 200 was a vertical reed 2.4L motor without fingerports and 175 was a 2.0L with the big open exhaust. The 1981 v200 is very close to the same power of the mid 80's 175 . . . it just doesn't have fingerports. So the mid 80's 175 is actually a bit stronger if run it with a 200 exhaust tuner.

This is the combo I run on my boat and it's really really fuel efficient . . . not that we'll be thinking about that with Gas back down to $1.60

This is my cruise with a mid 80's 2.4L 175 powerhead on 200 mid section pushing 23 seacraft. Performance was almost identical with the v200 powerhead.

[THEFERMANATOR]

My 81 150 is the most fuel efficient engine I EVER ran in a large outboard. It was on a bass boat, but I could run for HOURS on a 14 gallon tank. Running along at 3600 or so it only burned 4-5 GPH which was a FAR CRY from my 2.5L XRI 150 I had on my flats boat that burned 11-12 GPH running the same speeds at teh same RPM's with the same pitch prop.

[jamesbalog]

I have an 81 2.4 200 merc on my boat now and love the thing, it replaced an 88 175 johnson. The difference in fuel economy is night and day, the 2.4 merc wins hands down

[THEFERMANATOR]

Originally Posted by jamesbalog

I have an 81 2.4 200 merc on my boat now and love the thing, it replaced an 88 175 johnson. The difference in fuel economy is night and day, the 2.4 merc wins hands down

The 88 175 JOHNSON was a cross flow fuel HOG! The old OMC cross flow engines were as reliable as ANY outboard ever built, idled good, and had gobs of bottom end power, but they could drink fuel like NOBODIES business. Still can't believe MERCURY got rid of the 2.4L engine that had good power and GREAT economy for the 2.5L that drinked fuel in the same league as the OMC cross flow engines.

[jamesbalog]

Originally Posted by THEFERMANATOR

The 88 175 JOHNSON was a cross flow fuel HOG! The old OMC cross flow engines were as reliable as ANY outboard ever built, idled good, and had gobs of bottom end power, but they could drink fuel like NOBODIES business. Still can't believe MERCURY got rid of the 2.4L engine that had good power and GREAT economy for the 2.5L that drinked fuel in the same league as the OMC cross flow engines.

I didnt get into the numbers but by looking at my bank statement i bet im getting around double the MPG out of the merc