Afishionado Posted August 24, 2005 Report Share Posted August 24, 2005 Opinions please............. I have a 60hp oil injected carburated 2 stroke Tohatsu that powers the boat (Samurai) very well, but we are using between one and a half and two full tanks of petrol per session. Or 10 gallons in old money so at virtualy Quote Link to comment Share on other sites More sharing options...
Maverick Martin Posted August 24, 2005 Report Share Posted August 24, 2005 Mike What distances do you travel for your 10 galls or 45.5litres? Comparing between my boat and your boat is not really a fair comparison but you may find it useful. Maverick has a new generation Direct injection 2 stroke. The engine is a 150 hp with a big 6 cylinder 2.5litre block. She will cover approximately 1 mile per litre which when you consider the size of boat, speeds we can travel and the weight of the boat it ain Quote Link to comment Share on other sites More sharing options...
duncan Posted August 24, 2005 Report Share Posted August 24, 2005 don't forget that the 4 stroke saves the oil as well (but normally increases the servicing (costs) sticking the same power unit on and using it the same way you might see 20% according to some of the comments I have seen else where. where both 4 stroke and direct injection seem to really seem to score is where larger units are run at lower throttle settings. here the relative savings are significantly greater - Maverick for example is probably 40% better off than the 150 carburated unit when running at 3500rpm. I wouldn't bother to change now if you are happy with the engine you have otherwise. DFI and 4s have a way to go in their competitive cycle and their prices will come down in due course - ie it's an issue for the new boater and when replacing a broken engine! Quote Link to comment Share on other sites More sharing options...
Adam F Posted August 24, 2005 Report Share Posted August 24, 2005 ...As Martin says, we need to know the miles you would expect to cover with 10 gallons. BW has a brand new (1 yr old) 60hp EFI 4 stoke Mariner. I also carry 2 x 25l (10 gallon) tanks. It varies depending on the sea conditions, tide and the amount of people / gear we carry - but on average we travel 2 up. I work on just under 1 litre per mile - this gives me a range of 60 miles approx. Very seldom do I need to take another tank - and more often than not 1 tank suffices for the whole day. James gets slightly better than this (65 miles?) - he has a 70hp Suzuki - EFI 4 stroke - I think the benefit he has is not better technology, but the fact he has 10 hp more - meaning he can travel at the same speed as me but at lower revs, if I re-engined BW again I would go for the 70/75hp. Hope this helps Adam Quote Link to comment Share on other sites More sharing options...
Afishionado Posted August 24, 2005 Author Report Share Posted August 24, 2005 Quote .......What distances do you travel for your 10 galls or 45.5litres? Yes bl00dy fool me I shoulda said OK for those with a gps they can work and know these things........ Cobbs to Christchurch ledge, one or two marks in that general area and back to Cobbs was virtualy two tanks worth. (about a liter sloshing about was all that was left) Or Cobbs to B'mth pier whizing about at the end of each drift for a morning, back to Poole (Brownsea), whizing about at the end of each drift for about an hour or so, then back to Cobbs via PYC equaled a tank and a half. At the moment I am agreeing with Duncans feelings Quote Link to comment Share on other sites More sharing options...
Adam F Posted August 24, 2005 Report Share Posted August 24, 2005 I also agree with Duncan's comments - as there is alot more to this than just fuel economy - just for the record - I would be very confident, in fact I would put alot of money on it - that I could get from Cobbs to the Ledge and back with a bit of moving and drfiting in between on just 1 tank (25 ltrs) SO, camparing the two engine economies that is a saving of Quote Link to comment Share on other sites More sharing options...
Newboy Posted August 24, 2005 Report Share Posted August 24, 2005 I have the Tohatsu 90 tldi, I presumed it's the tldi you are aftering?! I used a tank (20litres) and half to the ripps and a tank ran dry at the buoys outside Poole entrance on the way back (calmer weather). Fuel consumption across the board with 90hp 4strokes and Di is very much comparable between Mercury 4s, Suzuki 4s ( same as Johnson 4s), Yamaha hpdi, Honda 4s, Tohatsu tldi (same as Nissan) and Evinrude etec. Don't know if you remember, that trip we took on Sweet Honey with its old Mercury 100hp, Cobbs to Old harry, across to southbourne, bournmouth pier and back to cobbs used about 12 gallons. My new tldi 90, uses about half the amount of unleaded comparing to the 100. I think there's isn't that much between the different makes and each shines in different aspects, i.e., noise, fuel economy (low, mid and max rev), hole shot, .... If you go to the Tohatsu website, in the tech bits, it tells you what their respective fuel comsuption are (not that they will relate to your boat, but at least it gives a comparison between the 2). Tohatsu tech bits Quote Link to comment Share on other sites More sharing options...
Coddy Posted August 24, 2005 Report Share Posted August 24, 2005 Hi Mike Like Adam I have a 60hp Mariner 4 stroke. I monitor my fuel usage for each trip and the costs, so far for the year it is 0.88 ltrs per nautical mile ( I think a nautical mile is slightly longer than a land mile) I would agree with Adams assessment of one tank from Cobbs to Xchurch and back. I have been discussing a similar thread on an other group one of which has a Raider 18 with a Merc 75 4 stroke and seems to get better fuel ltrs/mile than me at times. A 2 stroke mariner Big Foot on a 165 burns slightly more fuel but gets up on the plane quicker. Like Maveric, extra power means lower throttle setting = better fuel economy. I agree that if i changed engines it would be for a bigger capacity and differant make, proberbly Suzuki as Honda have been having problems lately so I have heard. Mariners are OK but are a bit crude and noisy at higher revs. Think of them as a Ford ........ cheap and chearful and spares/repairs readily available. Engine trim can make a difference in consumption so it is worth experimenting. Warrior type hull designs are terrible at low non planning speeds for fuel consumption, but in a choppy sea I don't fancy my back or legs getting hammered. Coddy Quote Link to comment Share on other sites More sharing options...
Seamouse Posted August 25, 2005 Report Share Posted August 25, 2005 Like Adam I have a 60hp Mariner 4 stroke. Hi Mike, To elaborate on what Dave said......our boats are identical in spec and engine make, except that I've got 2 stroke and Dave's got 4 stroke. Makes the comparison very direct. He gets 5mpg, I get 4mpg (both calculated to nautical miles across a full season). Obviously there are some differences - Dave carries too much fuel ( ) but is gentle while I tend to cane Lookfar, which for 2 stroke economy actually isn't too bad a thing. So you are calculating the savings based on 20%, not 50%. It ain't worth it! Steve an added thought is that the 4 stroke 60's seem to have less low-down torque, they can struggle to get a heavily loaded 165 out of the hole. Quote Link to comment Share on other sites More sharing options...
Bob F Posted August 25, 2005 Report Share Posted August 25, 2005 I get around 25-35 miles from a tank of fuel with a Suzuki 70HP 4 stroke and Alaska 500. The advantages of the 4 stroke: - vastly less noise and vibration. - virtually no fumes. - no need for oil mixes. - fuel economy, especially for low speed trolling. Disadvantages: - servicing can be a little more expensive, but after the warranty period is over you can do 95% of the servicing yourself. - can be be slower to pick up from stationary which makes getting to planning speed a little longer when heavily laden. But this was easily overcome by fitting "Dolfin" wings. Also gives a much smoother ride, although you do loose 2 mph on top speed. But most of my fuel economy came from dropping the revs when cruising. Nowadays I prefer to arrive 5 mins later and shave a lot of fuel. Also check that you have got your trim set correctly when crusing. This can make a big different to the fuel economy. BF Quote Link to comment Share on other sites More sharing options...
Afishionado Posted August 25, 2005 Author Report Share Posted August 25, 2005 All duely noted and thank you for your thoughts guys. It seems that I am firmly in a sorta 'If it works, don't fix it' situation. The engine goes splendidly and will push the boats speed far beyond my and Marks comfort level. Most of our traveling is done at between 2/3rds and 1/2 throttle. I guess we will have to 'pay the ferryman' and shut up. Humm? Any ideas how to get an outboard to spontainiously explode whilst one is several miles away (with witnesses)? If so I'll just check the fine print on the ol' insurance and I'll get bactk to you for the details. Mad Mike Quote Link to comment Share on other sites More sharing options...
great white Posted August 25, 2005 Report Share Posted August 25, 2005 Mike your last comment that you drive the boat at half throttle may be the cause of your fuel consumption worries. unless your boat is easily planning you will use more fuel. ie slow speed and bad weather will put up the gph figure a lot. get the boat up on the plane then throttle back to an engine RPM where it is still planning. any slower and you will be using the boat in displacement mode and using a lot more fuel. In my last planing boat with a New 60hp 2 stroke the long slow run up and down poole harbour from Hamworthy to the ferry used as much as the rest of the day zooming from mark to mark. Charlie Quote Link to comment Share on other sites More sharing options...
Afishionado Posted August 25, 2005 Author Report Share Posted August 25, 2005 I take your point Charlie but even a half throttle she is just nicely on the plane. If it's lumpy I drop back to displacement speed as I hate the nose up semi displacement attitude some boats adopt when being pushed beyond displacement but not enough to get over the 'hump' and actualy plane. And as I am only little I can't see over the bow when it's ar5e down and sharp end up Mad Mike Quote Link to comment Share on other sites More sharing options...
Coddy Posted August 25, 2005 Report Share Posted August 25, 2005 Humm? Any ideas how to get an outboard to spontainiously explode whilst one is several miles away (with witnesses)? If so I'll just check the fine print on the ol' insurance and I'll get bactk to you for the details. Mad Mike Hi Mike I could pretend to be a Pirate, I have the flag on the boat already, or be a submarine and rescue your engine as it falls through the water after the explosion. Remember the rules of salvage at sea - finders keepers Coddy Quote Link to comment Share on other sites More sharing options...
Afishionado Posted August 25, 2005 Author Report Share Posted August 25, 2005 Coddy confidently claims....... finders keepers Yes but can you afford to run it? Mad Mike Quote Link to comment Share on other sites More sharing options...
john c Posted August 26, 2005 Report Share Posted August 26, 2005 Not rubbing it in but Mad Mller, Arvor 20, 1500kg semi-planing does 14 - 19 knots at full stick which is the only throttle setting we use, returns 2 gallons per hour or now just over as her bottoms dirty. Maths = 20p per litre ( very variable) x 4.5 = 90p per gallon Quote Link to comment Share on other sites More sharing options...
Bob F Posted August 26, 2005 Report Share Posted August 26, 2005 Sounds good to me John C. If I get another boat it will be a 20 mph max diesel jobby. BF Quote Link to comment Share on other sites More sharing options...
Afishionado Posted August 26, 2005 Author Report Share Posted August 26, 2005 Sounds good to me John C. If I get another boat it will be a 20 mph max diesel jobby. BF That'll be good by to trailers then And hello to mooring fees, antifoul, lift out lift in and that averages out at 25p every time the engine does a revolution Can't bl00dy win can we Mad Mike Quote Link to comment Share on other sites More sharing options...
Maverick Martin Posted August 26, 2005 Report Share Posted August 26, 2005 and by then there will be no duty free (red) diesel...oh dear Quote Link to comment Share on other sites More sharing options...
jack Posted August 27, 2005 Report Share Posted August 27, 2005 Andy is always worried about the fuel consumption on Pal-o mine [arvor 25] He doesn't seem to be able to get it to use enough !!.we trudge it round to the fuel pump and when the price comes up ,he mutters and mumbles about "it can't be full !". For our last three trips {full days out } we have not had a fuel guage [sender packed up] we carried spare cans in case ! but last week we went out,having had the sender replaced,and it showed over 1/2 full. and after that day out,you could barely see any movement in the level. He always keeps at 2.5 revs and we seldom exceed 17knots. So he must be doing something right.!! ..jack Quote Link to comment Share on other sites More sharing options...
Sam Posted August 27, 2005 Report Share Posted August 27, 2005 you all need a boat like gw only a fiver for a days fishing and we go just as far as you lot just takes a bit longer. i agree with you 75hp is the best just spent 2 days on a rib with 75hp 20 knots at only 3/4 throttle lovely sam Quote Link to comment Share on other sites More sharing options...
Paul D Posted August 27, 2005 Report Share Posted August 27, 2005 or on the other hand you could get a Boston Whaler with a 75 HP Mercury 2 Stroke and go from Bridge Street in Christchurch to X-Ray ( ie. Southbourned Rough ) and back on 25 litres of fuel ..... Quote Link to comment Share on other sites More sharing options...
Paul D Posted August 31, 2005 Report Share Posted August 31, 2005 Done some calculations on Neo ( Orkeny 520 with 30HP 4Stroke Honda ). Put on the 12 litre tank and carried the 25 litre tank in the front ( in a vain attempt to distribute weight better ). Myself and Paul J travelled out from Wick to X-Ray in a slightly lumpy sea ( wind against tide ). Fished and then travelled over to Barton ( on a flatter sea by now ). Flat out all the way ( ie. 13-15 knots ). Fished Barton and then came back to Wick. Total distance travelled was 18 Nautical Miles and the 12 litre tank ran out halfway up Christchurch Harbour. Therefore just under 1.5 NM per litre. Quote Link to comment Share on other sites More sharing options...
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