transome to propshaft hight

[kencr250]

i have a ranger 1850 with a 175 e tec, boat weighs 1800# dry, the distance from the botom of the transom to the center of the prop shaft is 5.5 inches, i am runing a 19 cyclone 4 blade, boat runs 47 at 5100 rmps, and i carry a lot of fishing equipment, and have 5 bateries on board, plus a 9.9 kicker, i think i should be able to get more mph out or the engine

[Trippin]

I would delete 2 batteries and add a Bob's machine hydraulic jack plate to change your running prop height. I think you'll be able to milk it for more MPH that way, and do it cheaply. Is the Cyclone a chopper? Use 93 Octane fuel, not 87.

[kencr250]

what would the gain be of using 97 octane, speed?, perfomance?,run better?

[hsbob]

what's the manual call for. using more octane than required wont help and could cause long term problems. these are not 4 cycle motors.

[stokernick]

IMHO,motor's too deep!

[kencr250]

manual calls for 87 octane, i agree props to deep, need a jack plate now to bring it up, manual or hydralic ?

[E-tec1]

where is the cav plate at, even with the bottom?

[Trippin]

The manual "recommends" 87 Octane fuel. Higher octane fuel burns cleaner, slower and more evenly. 2 stroke motors don't have knock sensors so running a poor quality gasoline will only contribute to poor performance and long term problems.

The 87 Octane preference so dictated by engine manufacturers is to ensure that those who purchase the units overseas where quality fuel is not as available have a guide as to the lowest acceptable fuel quality to use in the motor. That doesn't necessarily mean that the company themselves insist that you the consumer use the lowest quality fuel available.

Yes the motor should run and perform to expectations on 87 Octane fuel, but if by running a higher quality fuel you get better perfomance and a cleaner longer lasting engine wouldn't you do it?

There are lots of people who don't believe in this philosophy, but given my experience with all kinds of inboard and outboard motors, I wouldn't skimp on fuel or oil quality.

I'd like to know what long term problems are caused by running a higher grade fuel, please articulate.

[kencr250]

my 15 years experiance with two stroke motocross race engines was run higher 93 octane amoco or shell, and good oil, but we still had a lot of carbon deposits, there are no negatives except cost, only slight perfomance gains, do to leaner jeting, and sythetic oil

[kencr250]

my 15 years experiance with two stroke motocross race engines was run higher 93 octane amoco or shell, and good oil, but we still had a lot of carbon deposits, there are no negatives except cost, only slight perfomance gains, do to leaner jeting, and sythetic oil

[kencr250]

5.5" from bottom to cav plate

[Riverman]

If the manufacturer says use 87 octane fuel, then it is fine. They are the experts. You can use premium fuel, you can also throw your money in the lake. Your call.

If your cav plate is even with the bottom of the hull then you can probably come up somewhat higher. If you carry a lot of weight then some setback is in order too - looks like you should go shopping for a jackplate.

[kencr250]

that should be the case

[Trippin]

Best of luck.

[gw1250]

The manual "recommends" 87 Octane fuel. Higher octane fuel burns cleaner, slower and more evenly. 2 stroke motors don't have knock sensors so running a poor quality gasoline will only contribute to poor performance and long term problems.

The 87 Octane preference so dictated by engine manufacturers is to ensure that those who purchase the units overseas where quality fuel is not as available have a guide as to the lowest acceptable fuel quality to use in the motor. That doesn't necessarily mean that the company themselves insist that you the consumer use the lowest quality fuel available.

Yes the motor should run and perform to expectations on 87 Octane fuel, but if by running a higher quality fuel you get better perfomance and a cleaner longer lasting engine wouldn't you do it?

There are lots of people who don't believe in this philosophy, but given my experience with all kinds of inboard and outboard motors, I wouldn't skimp on fuel or oil quality.

I'd like to know what long term problems are caused by running a higher grade fuel, please articulate.

Your compression dictates the octane of fuel that you should be using. If the recommended octane for your set up is 87 then run 87. The only reason you would use a higher octane is if your compression was increased, only then due you benefit from the octane increase. When you raise the combustion pressure the air/fuel mixture will ignite prematurely if you don't raise the octane. All the extra octane does is suppress the ignition of the mixture until you reach an optimum pressure. Just because it is 93 compared to 87 does not dictate the quality of the fuel either, it simply describes the % make up of the gasoline mixture. i.e. 87% iso-octane & 13% n-heptane yields gasoline of 87 octane. Run what was recommended.