PDA

View Full Version : Which Fuel???



copie
25-08-2011, 07:18 PM
70847Hi everyone just wondering what fuel (petrol) you all use in your boat when fitted with a four stroke engine. I have recently purchased a new (second hand) boat that has a 150hp honda four stroke engine.
Thanks in advance Mark.

jason p
25-08-2011, 07:46 PM
have a look in your manual it should state what is recomended as far as the octain and wheather you can use a feul blend (ethanol) at a % rate. in saying that, my zuk manual says it's ok to use a 10%ethanol feul mix but i wouldnt use it, unless it was the only option and even then i would quiver. i only use the premium stuff like vortex or the like. it may be 15+ cents dearer but my mind is at peace. not sure if this helps the the milage or not but its gotter be better for my engine.

jp

jason p
25-08-2011, 07:47 PM
nice looking rig mate

jp

Dignity
25-08-2011, 08:36 PM
Copie,that's a great rig, I'm with jp the best quality and octane you can get, forget the ethanol and generally I try to only fill up from a station that I am comforable with. Unfortunately where you are there isn't much to choose from although the mobil a bit down the road used to be good, I still stay down that way but no longer need to fuel up there.

Argle
26-08-2011, 12:14 PM
95 octane or 98 and steer well clear of anything to do with ethanol - Nice rig too mate congrats!

Cheers
Scott

copie
26-08-2011, 07:35 PM
Thanks so far guys do any of you have honda engines.

Lachie1
26-08-2011, 09:05 PM
I had a 90 honda on my last rig mate and used regular unleaded and occasionally the 10% ethanol blend. Never had a problem at all with the engine running on this and i don't see the point in paying extra for the premium fuels when they are of no benefit to the engine.

Congrats on the rig, that silver donk on the back will serve you well.

Regards,

Lachie

Spaniard_King
27-08-2011, 08:11 AM
Copie,

The 150 has lean burn technology nuthing like the old carby tech engine. If you have fuel which has lost it's octane the oxygen sensor will retard the timing reducing the performance of the engine it does this to safeguard the engine against possible damage. For this reason I recommend that you use 95 octane fuel which has a longer shelf life than standard unleaded.

dnej
27-08-2011, 08:23 AM
Mark, I have to say, if Garry says something about outboard motors, you can rest assured that what he says, is always the way to go.
David

copie
27-08-2011, 09:25 AM
Thanks Garry i did check the book and it recommends fuel with 91 oct or better but i also know we have poor quality fuel in australia.
Do these engines also have a knock sensor.
Yeh it will be 95 or 98 for me.
Mark.

stevel3
27-08-2011, 10:48 AM
I also have a bike and on that forum the issue of fuel was raised, this is some of what was said

Thought I should bring this to every ones attention who are using 98 octane fuel in bike or car.
Being in contact with clients and numerous bike mechanic's and shops and the persistence of my Boss, has discovered a bloody serious problem with 98 octane and the way it is stored.
The story begins with bike owners and clients ringing us for advice due to a poor running bike, fouling plugs every couple of thousands k's and less. Blocked carbie's or fuel injection
systems, and then we start getting request for replacement fibreglass fuel tanks. What was strange was some of these tanks weren't very old.
To cut a long story short,after months of research and investigations by numerous interested people, it was found that the 98 was eating the fibreglass
Certain companies have been trying to come up with a solution but to no avail at this stage and have also tried different linings in fibreglass holding tanks but none have succeeded yet.
Also what you may or may not be aware of is that alot of petrol stations store their fuel in fibreglass tanks. Bugger I checked where I get my fuel from and was told that they have fibreglass tanks and I've been using 98 in my car as it's a turbo and that's what's recommended, so #### it I'll use 95.
When I know more I'll let you know.

The other issue which was brought to my attention was at the Toll trucking depot here. Their petrol pumps at the Depot are having their rubber seals replaced for the third time. The seals are being eaten away.
I will not use ethenol 91 as it has also been eating away at the fibreglass also, I'll only use 91 or 95 but who's to say what blends are being delivered to your local station.
Unfortunately the fuel we are served up with is the rubbish left in the tanks at the oil distilleries after the chemical companies have taken the better quality fuels.
Will a Government department or official come out and warn the general public, of course not, fuel is a dirty word.

I now only use 95 octane in my bike and boat and my ute is on LPG.

jason p
27-08-2011, 11:04 AM
intresting stevel3, im going to look into that alitle further as thats all i use is 98 (what you say on this garry). also beaware that some of the 95 is also a ethanol blend, wich they usually state at the bowser but dont go and pick up a 95 oct hose and odermaticly think its ok.
jp

Fed
27-08-2011, 11:36 AM
It would not surprise me one bit if the petrol companies were sneaking ethanol into supposedly non-ethanol fuel.

stevel3
27-08-2011, 01:00 PM
yeah I never use any ethanol fuel at all, I was told a long time ago that the ethanol content attracks water into the fuel which is obviously a bad thing. I used to carry Castrol and BP products and was talking to one of the staff there and he told me how bad the water problem is at most servos.

ps awsome looking boat mate

FishHunter
27-08-2011, 01:41 PM
Copie,

The 150 has lean burn technology nuthing like the old carby tech engine. If you have fuel which has lost it's octane the oxygen sensor will retard the timing reducing the performance of the engine it does this to safeguard the engine against possible damage. For this reason I recommend that you use 95 octane fuel which has a longer shelf life than standard unleaded.

Umm sorry but I dont think that is 100% correct

My understanding of engine management systems is O2 sensors measure oxygen content and the ecu varies the fuel mixture based on that information. Knock sensors are used to detect the onset of detonation and the ecu will retard the timing to prevent engine damage if detonation occurs.

http://marine.honda.com/why/hondamarinetechnology

From Wikipedia

Honda lean burn systems

One of the newest lean-burn technologies available in automobiles currently in production uses very precise control of fuel injection, a strong air-fuel swirl created in the combustion chamber, a new linear air-fuel sensor (LAF type O2 sensor) and a lean-burn NOx catalyst to further reduce the resulting NOx emissions that increase under "lean-burn" conditions and meet NOx emissions requirements.
This stratified-charge approach to lean-burn combustion means that the air-fuel ratio isn't equal throughout the cylinder. Instead, precise control over fuel injection and intake flow dynamics allows a greater concentration of fuel closer to the spark plug tip (richer), which is required for successful ignition and flame spread for complete combustion. The remainder of the cylinders' intake charge is progressively leaner with an overall average air:fuel ratio falling into the lean-burn category of up to 22:1.
The older Honda engines that used lean burn (not all did) accomplished this by having a parallel fuel and intake system that fed a pre-chamber the "ideal" ratio for initial combustion. This burning mixture was then opened to the main chamber where a much larger and leaner mix then ignited to provide sufficient power. During the time this design was in production this system (CVCC, Compound Vortex Controlled Combustion) primarily allowed lower emissions without the need for a catalytic converter. These were carbureted engines and the relative "imprecise" nature of such limited the MPG abilities of the concept that now under MPI (Multi-Port fuel Injection) allows for higher MPG too.
The newer Honda stratified charge (lean burn engines) operate on air-fuel ratios as high as 22:1. The amount of fuel drawn into the engine is much lower than a typical gasoline engine, which operates at 14.7:1—the chemical stoichiometric ideal for complete combustion when averaging gasoline to the petrochemical industries' accepted standard of C6H8.
This lean-burn ability by the necessity of the limits of physics, and the chemistry of combustion as it applies to a current gasoline engine must be limited to light load and lower RPM conditions. A "top" speed cut-off point is required since leaner gasoline fuel mixtures burn slower and for power to be produced combustion must be "complete" by the time the exhaust valve opens.

rowanda
27-08-2011, 02:23 PM
98 won't eat fibreglass...unless it's one of the "no name" brands that also contain ethanol. Yes you shouldn't use E10 in
your boat or small engines (I won't use it in my car either...just don't like it) For those using E10 in their boat and are having no problems watch your filters as ethanol will "clean" your tank and liberate any crap in it, which in turn will end up in your filters. It will also run fine in your motor, but it needs as little as 1% water in your tank (not that hard in a boat tank) to have phase seperation and I hope that doesn't happent to you at sea.
As for water in servo tanks, depends on the site. I can tell you 99.9% have no problems, but it'll be the smaller ones "mostly"
that don't want to pay to have water removed till it gets to a certain level.
I just love how people that don't work in the industry know it all....

Spaniard_King
27-08-2011, 03:15 PM
Thanks Garry i did check the book and it recommends fuel with 91 oct or better but i also know we have poor quality fuel in australia.
Do these engines also have a knock sensor.
Yeh it will be 95 or 98 for me.
Mark.

All EFI 4 stroke and most DFI 2 strokes have knock sensors, combined with an 02 sensor you have a near failsafe mechanism for bad fuel which could damage your engine