Gas Consumption Merc 850 6l Vs Merc 115 L4

[mk30h]

Guy's anyone care to offer an opinion on relative gas consumption of these two engines a 1964 Merc 850 or a 1000 6 inline 89 ci and 1995 Merc 115hp 4 inline looper 113 cu in. The 64 850 wieghs about 100 lbs less than the new 115 and has less cubes, but the new engine is a looper. Any ideas as to how they would stack up against each other fuel wise. I have an old boat with a 115 on it now but I am concerned that the engine wieght is hurting the transom. The boat was designed to hold a 6 inline merc 1000, but when I recived it, the engine had been relpaced with the 95 115. I have a old 850 in excellent condition along with a 1000 block if need be.

[MagicFloat]

The old inline 6's,as sweet and reliable as they are,are gas hogs compared to the new stuff. But I have to respectfully ask,so what? They start and run and idle smoothly and very rarely break,and if they do,parts are available. I run a 1968 1000,1968 1250,and a 1967 1100,every chance I get. Yeah, they suck up the fuel a little,but it's not a big deal to me.If fuel economy is the desire,the new 4-strokes will get you there,but more weight,more money,and more maintenance. I may be old,but I like the old,simpler stuff. My 2 cents

[mk30h]

Sort of the way I was thinking. The 4cly 115 hp I have is the 2 cycle looper, there is no way my boat could handle the weight of the 115 4 stroke- it would slowly pry the transom right off. I'll post some pictures in the next week of the boats I am restoring and some of the problems that seem to have been the result of the added wieght and postion of the clamps of the new mercs.

Besides the old babies look sweeter on the back of the boat- much slimmer.

[Dave S]

The new 115 4 cly has lots of power, more than your old boat needs to have fun with. Put on a 115 dist on that old classic 100hp and enjoy.:) A good prop and set-up will give better gas use. I used to lean them out in the old daze when gas went to .75 a gallon.:eek:

[Raceman]

I just don't believe the weight of the engine is as significant a factor as the thrust, when it comes to transom strength.

[Markus]

I just don't believe the weight of the engine is as significant a factor as the thrust, when it comes to transom strength.

Same here. I never bought into those "transom savers" either.

[mk30h]

Thanks Guys,
I'll post some pictures of the boats I am taking about this week, Both are Lapstrake construction -very light and strong. Have a broken rib and plank in the rear so she has to be turned over and I have to get dirty.
How difficult is it to convert an old 850 to Thunderbolt ignition? and is there a real advantage?

Gas up here just went to $1.09 litre, so the old tanks cost about $26 to fill. Just wondering, Marcus what is the cost in Sweden these days? I expect that we will be paying a lot closer to your prices in the next year or so.

[mk30h]

Thanks Guys,
I'll post some pictures of the boats I am taking about this week, Both are Lapstrake construction -very light and strong. Have a broken rib and plank in the rear so she has to be turned over and I have to get dirty.
How difficult is it to convert an old 850 to Thunderbolt ignition? and is there a real advantage?

Gas up here just went to $1.09 litre, so the old tanks cost about $26 to fill. Just wondering, Marcus what is the cost in Sweden these days? I expect that we will be paying a lot closer to your prices in the next year or so.

[Markus]

95 RON = 90 (R+M)/2 costs CAD 1.94/liter in most places. The lowest I have seen is in the past two days is CAD 1.85/liter.




Gas up here just went to $1.09 litre, so the old tanks cost about $26 to fill. Just wondering, Marcus what is the cost in Sweden these days? I expect that we will be paying a lot closer to your prices in the next year or so.

[Dave S]

Just easyer to have a good runing motor.;) I just did one on a 100 merc, it is bolt on, the 115 dist is the same. Just a bit longer. Ya gotta find places to mount the coil and black box. The newer coils are smaller than the 1969-1975. 3 small bolts hold it on.:)

[Mark75H]

The itty bitty coil for 2 cylinder OMC's works fine, much easier to mount. ;)

[mk30h]

Thanks guys. I'll post some pictures tommorrow of the boats that I am in the process of restoring. I am about 2 weeks behind scheduale getting them wet, Two boats on the go and I completed but with a god forsaken 3cly 60 hp that I am getting ready to kill over. I want to replace with a mark 75 or Merc 700. But my father insists on keeping the power trim for the 84 60hp. might swithc the powerhead with a 69 500, at least I trust the 4cly than that sad excuse for a merc 60hp.

Marcus,
I'd be willing to bet that we will have the same prices in this area once the Hurricane season starts in the Gulf. Seeing a trend towards smaller outboards in this area. Lots of Yamaha and merc 4 strokes. Virtually zero suzuski and a few hondas.

[Dave S]

If you use one off a 99.9 cid motor, you have to cut the shaft where the pully mounts. The 99 block has a thicker bosse and the pully is higher.;) Use the power trim from the 60 on the Mark 75.:D The Merc 1000s can be real sweet runniers with a good ignition.

[raymar]

Mark30h,
A distributor from a Merc 90 cubic inch block will fit the 850 inline 6 without alterations. Look for a 950, 1000 or 1100 Merc with Thunderbolt ignition to remove the parts from, as many of them are junked out by now.

Raymar:rolleyes:

[Mark75H]

Mark30h, A distributor from a Merc 90 cubic inch block will fit the 850 inline 6 without alterations. :rolleyes: ... probably because a 1964 850 IS a 90 cubic inch block :p 110's are 93 ... they fit the same, though. Watch out for late 1966 and 1967 distributors with point triggered Thunderbolt ... not worth having:(

[T2x]

For the record..... the old in line Merc 1000's burned right at 12 gals/hr WOT.
We used this number for computing race fuel loads and it gave us a cushion of probably 1 gal/hr ( resulting from throttling down for turns, wakes, etc).

The 85's with smaller carbs probably came in at about 10 gph.

My new 300 x's burn 30+gph WOT....so where is the "economy" from the new technology?

T2x

[Dave S]

100+100+100=300Hp same power, but are the new boats faster? Skip talbot went how fast with his 3 engine rig?????;)