Optimax troubles?

[MattyK]

I have just bought a new boat - a brand spanker Quintrex freedom sport. I just did the deal today on the phone, and go for a water test this weekend - YAHOOOOO!!!! However- the boat has a 115 Mercury 2 stroke on it. I still have the option of getting one of the new 115 Optimax fitted (at extra cost obviously) but have heard of a few problems with the compressor on the fuel injection for the Opti's. Has anyone else heard of this? Can anyone give me an idea of the fuel consumption of the 115 standard 2 stroke as I have found it very difficult to get any info on this matter for the standard 2 stroke.......any help or comments would be absolutely appreciated at this time.

[MattyK]

Banshee - would you consider then that you would not drive the boat for economy? I guess I feel that 50 litres for 2 hours running (25l/hr) to be fairly heavy on fuel? I would consider however that the boat I have chosen (5.3 aluminium) would be lighter, and might therefore use less fuel? How much fuel (in litres) do you carry? How have you found other aspects of the motor - such as reliability / useability etc? While it is an older design motor, I have heard even more questionable things about some of the new technology on some of the motors......while everything is fine under warranty - warranty doesn't last for ever! Again, any further comments would be greatly appreciated.

[banshee]

Hi Matt,I have an '02 115 Merc,typicaly I would use beetween 45 and 50 litres for every 2 hours on the hour metre,I have never sat down and worked it out exactly.It is some thing that would vary a great deal depending on the conditions and how you drive your boat.Mine is on a 5 metre Cruise Craft,in rough conditions I am on and off the throtle a lot and in good going I like to sit up around 5 thousand revs.I have two mates that have 135 optimax motors fited to 5.5 metre glass hulls,when we fish the same areas they consistantly use just under half the fuel that I do and neither drive to conserve fuel.Having said that,I could buy a shit load of fuel for the extra six grand or so these motors cost compared to mine,I also think they cost a lot more to service over the the life of the motor.I have never heard of any complaints with these particular two motors.I hope this helps.

[Lucky_Phill]

As Banshee suggested, the extra 6k might seem over the top and take a long time make up economy wise. BUT, lets talk, Quietness, Let's talk, Re-Sale, Lets Talk exhaust fumes.

A few good reasons to go the extra mile, in my opinion.

With the 115 on the Quinnie, fuel useage should be under 12 litres an hour.

We got a 130 4 banger on a boat the weights just on 1.3 tonne in the water, and she pulls 16 litres an hour.

YES, earlier models did have troubles with all sorts of things.

Cheers Phill

[NQCairns]

Hi I haunt the US boat boards sometimes and have read some very poor opinions about the earlier optis and reliability, the late models are supposed to be better nearing quite good, I guess it takes a lot of time and the will to iron all the problems out of a new product. Those american guys really work outboards hard though. I think the Tohatsu uses the same technology?Nq

[banshee]

G'day Matt,it would be fair to say that when I drive my boat economy is the last thing on my mind.I discussed this topic with the Mercury mechanic today and he thought that my figures sounded a little heavy,he said 18 to 22 litres an hour would be close to the mark for me .My boat carries 120 litres in the tank I have never looked like running out,My longest trip was from Turkey Beach out to the rock cod shoals,6 hours looking around/fishing and back and still had quater of a tank(gauge).My set up weighs 1.35 tonnes including the trailer so I would say the boat is a frag over 1 tonne, a lighter boat should return better figures especialy if you can sit around the optimum cruising revs.My motor is the newest of 5 115's in our club,no one has had any trouble.If you go for the 115,do not flush it with the supplied fitting,my mechanic disconected it and gave me a set of muffs.Your dealer will explain the 2 cylinder idle thing,this is a great feature for slow trolling(these things run on nothing under 2000 revs).I hope this helps a bit.

[opimax]

giday i am running a 135 opimax on my boat only 40 hrs but a top donk. i think lucky_ phil hit the nail on the head. its just like a 4 stroke but with the get up & go of a 2 stroke, i am glad i spent the extra bucks. lee

[banshee]

Just caught up with two other 115 owners,one bloke has a modified V-Sea(pod,solid glass transom)his absolute best return was 20 litres per hour,this was in the river 1/2 hour one way,1/2 hour back just after it was run in done specificly to see what the return would be.Outside he expects between 20-25 litres per hour.The other bloke has a 19 foot older style Mustang,his return is around 23-25 litres per hour.I don't know of any 115 motors mounted on alloy boats(except twin 115 mounted on 7m Yellowfin-47 lph average)so can't help there.

[MattyK]

Well people, thankyou very much for your comments. I would seem to me that both parties (ie those that own the Opti's, and those with the standard 2 strokes) are more than happy with their motors, and can do what they want with their vessels with little worry. I will not argue that the appeal of lower fuel consumption is very appealing, as is the anticipated resale value. However, the cloud of possible hassles, and extra purchase price / service expense is a strong reason to stick with a known product! I guess this sounds like I am still a bit undecided. I will be going for a test ride on Saturday with the standard 2 stroke fitted, and will have to make a decision then. I would like to thank all who have contributed to this thread, your comments have been well received....

[Mudcrab]

Have a look at this and decide:

http://www.continuouswave.com/ubb/Forum1/HTML/003763.html

or go to www.altavista.com and do a search for
Mercury +Optimax +Problems
in the search line. Forget all the manufacturers and plod around till you find similar sites to the above.

We have a few Optimax's (2 i think) in the rescue units but policy moved to the 4-strokes. Give Wayne Cross at Northside Marine a call (3265 8000) and tell him Ian Fischer suggested the call to get a down to earth opinion on them. You can trust Wayne to give you a no nonsense answer. He can build a motor out of a paper clip!

Overseas reports indicated an excellent powerhead but the stuff hanging off it and the lower leg were(?) causing some problems.

Better yet, grab a 2nd. hand 90 hp Honda 4-stroke and solve everything. After sales service is zero but a magic motor nonetheless.

[davo]

When I was looking at Outboards I thought about a TLDi Tohastu but stayed with a 4 stroke. The Tohastu's use a different system to Merc, their's is a Mitusbishi (I think) electric system. Recently I spoke to a bloke with a 90HP Tohastu TLDi and has already replaced the air pump on his while the rest with 4 stroke Yammies had no problems. After owning a 4 stroke both me and my father have switched. We even run a little 6HP 4stroke Tohastu on the punt.