might repower
 

hearing from lots of folks that my 92 johnson 175 ,if i ever get it fixed is a major gas hog. so i am thinkin instead of having it rebuilt i might look around for a used motor instead. i am thinking a 200 might do better since it doesnt have to work as hard. i am scared of buying anything local since katrina. anybody out there know of any sites online where i can look for a used motor? tx

might repower
 

hearing from lots of folks that my 92 johnson 175 ,if i ever get it fixed is a major gas hog. so i am thinkin instead of having it rebuilt i might look around for a used motor instead. i am thinking a 200 might do better since it doesnt have to work as hard. i am scared of buying anything local since katrina. anybody out there know of any sites online where i can look for a used motor? tx

Re: might repower
 

My 200 Merc. loves sucking the fuel down. Would love a Johnson 115, maybe a 90 with todays gas prices. Even thinking about a set of oars and a sail. :D

Re: might repower
 

My 200 Merc. loves sucking the fuel down. Would love a Johnson 115, maybe a 90 with todays gas prices. Even thinking about a set of oars and a sail. :D

Re: might repower
 

Hey Racerx,

You already found what you're looking for as far as fuel economy.

http://cgi.ebay.com/RARE-Old-HAND-CR...QQcmdZViewItem


;D

Re: might repower
 

Hey Racerx,

You already found what you're looking for as far as fuel economy.

http://cgi.ebay.com/RARE-Old-HAND-CR...QQcmdZViewItem


;D

Re: might repower
 

My old 175 was a real gas hog! The new 115 Envinrude ficht I got is very impresssive. With a 15P prop it jumps out of the water and has as much top end as I want - maybe 35 or so (not broken in yet). I believe it will be very easy on fuel. Very quiet and no smoke.

Re: might repower
 

My old 175 was a real gas hog! The new 115 Envinrude ficht I got is very impresssive. With a 15P prop it jumps out of the water and has as much top end as I want - maybe 35 or so (not broken in yet). I believe it will be very easy on fuel. Very quiet and no smoke.

Re: might repower
 

My 1988, 175 Yamaha has been pretty good on gas, 3 mgh

Re: might repower
 

My 1988, 175 Yamaha has been pretty good on gas, 3 mgh

Re: might repower
 

MJ, I'm having a senior moment What is MGH? Bill Mc ;D

Re: might repower
 

MJ, I'm having a senior moment What is MGH? Bill Mc ;D

Re: might repower
 

Mac come on man, you know you will need another Wind Talker to get an interpration. Our only hope is CB, he's been around him long enough to perhaps have picked up some of the lingo ;D

Re: might repower
 

Mac come on man, you know you will need another Wind Talker to get an interpration. Our only hope is CB, he's been around him long enough to perhaps have picked up some of the lingo ;D

Re: might repower
 

Mallons Ger Hile...everybody knows that... ::)...

Re: might repower
 

Mallons Ger Hile...everybody knows that... ::)...

Re: might repower
 

Oh!



Bill Mc ;D

Re: might repower
 

Oh!



Bill Mc ;D

Re: might repower
 

yea grace, if i mount that on my boat, i bet the nieghbors will stop askin me to take them fishin, huh

Re: might repower
 

yea grace, if i mount that on my boat, i bet the nieghbors will stop askin me to take them fishin, huh

Re: might repower
 

Yeah, that's one way ;) The other way would be to put an ATM machine at the entrance of the boat with the current gas prices on it ;D

Re: might repower
 

Yeah, that's one way ;) The other way would be to put an ATM machine at the entrance of the boat with the current gas prices on it ;D

Re: might repower
 

I used to subscribe to the bigger motor may get better milage because it doesn't have to work as hard. Now, I have a better understanding of the dynamics of a running engine. There are 3 major reasons diesel engines get better fuel economy than gas engines. They have higher compression ratios, they have a higher heating value for their fuel (not much higher, though), and they have no throttling losses. Our fuel limits what we can do about the first two, but we can do something about the throttling losses. Open the throttle more. The engine burns more fuel per hour when you open the throttle more, but burns less fuel per horsepower per hour. It takes a certain horsepower to run a certain speed, so the engine with it's throttles open the most is going to be burning the fewest gallons per hour at a given horsepower and will get the best milage as a result. Smaller engnes require the throttles be open more to make the same horsepower as a bigger engine. In cars, bigger engines sometimes have an edge, though. Big engines make a lot of torque at low engine speeds. With big engines in cars, we use overdrive gears to really bring the engine rpm down. You may have heard of the equation horsepower = torquexrpm/5250. Well, in order to maintain speed, we still have to make the same horsepower despite the decreasing rpm. In order to do so, we have to increase the torque output. Torque output is controlled by throttle position. So, with an overdrive, we have to open the throttle more to make a given horsepower, our pumping losses are reduced, and our mpg go up. You might ask why can't I go wide open and run down the highway at 130 mph for best milage, then? Opening the throttle more only improves the gallons/horsepower/hr. At 65 mph, it takes 35-50hp to keep a car moving. At 130 mph, it takes 250-300 hp. To go double the speed, it takes 4-6 times the horsepower. Well, the difference in gallons/hr/hp between an engine with a barely open throttle and a wide open throttle isn't 4-6 times, it's more like 10-20%.

Re: might repower
 

I used to subscribe to the bigger motor may get better milage because it doesn't have to work as hard. Now, I have a better understanding of the dynamics of a running engine. There are 3 major reasons diesel engines get better fuel economy than gas engines. They have higher compression ratios, they have a higher heating value for their fuel (not much higher, though), and they have no throttling losses. Our fuel limits what we can do about the first two, but we can do something about the throttling losses. Open the throttle more. The engine burns more fuel per hour when you open the throttle more, but burns less fuel per horsepower per hour. It takes a certain horsepower to run a certain speed, so the engine with it's throttles open the most is going to be burning the fewest gallons per hour at a given horsepower and will get the best milage as a result. Smaller engnes require the throttles be open more to make the same horsepower as a bigger engine. In cars, bigger engines sometimes have an edge, though. Big engines make a lot of torque at low engine speeds. With big engines in cars, we use overdrive gears to really bring the engine rpm down. You may have heard of the equation horsepower = torquexrpm/5250. Well, in order to maintain speed, we still have to make the same horsepower despite the decreasing rpm. In order to do so, we have to increase the torque output. Torque output is controlled by throttle position. So, with an overdrive, we have to open the throttle more to make a given horsepower, our pumping losses are reduced, and our mpg go up. You might ask why can't I go wide open and run down the highway at 130 mph for best milage, then? Opening the throttle more only improves the gallons/horsepower/hr. At 65 mph, it takes 35-50hp to keep a car moving. At 130 mph, it takes 250-300 hp. To go double the speed, it takes 4-6 times the horsepower. Well, the difference in gallons/hr/hp between an engine with a barely open throttle and a wide open throttle isn't 4-6 times, it's more like 10-20%.