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Captain Bill · 31-10-2015, 12:25

The O-ring in my Fuel line connector on my 15 month old DF15a has given up the ghost (Halloween pun intended). The O ring appears to be 5/8 inch in OD and about 2 mm in cross section. I have 5/8 inch diameter o-ring with a 1.5 mm cross section, but it does not seal. I have one with a 2.5 mm diameter cross section that will not go over the connector. I have attempted to measure the cross section with calipers but don't actually trust the measurement on an old hard o-ring. Suzuki does not sell o-rings, only whole fittings. I can't believe I'll be forced to buy a new fitting because of a bad o-ring. Does anyone know the correct size of a replacement o-ring for this fitting?

Before you ask, I have already trolled though 5 pages of google hits and found no useful data.

**GordMay** · 31-10-2015, 12:38

Does this help?
➥ OEM Parts

**a64pilot** · 31-10-2015, 13:12

Mine started leaking at the first of this season, it was a year old. I had bought a couple as they come in pairs from Iboats I think so I just swapped it. I keep meaning to find the O ring size as I believe this will be a common failure.
I had bought extra so I could use my fuel tank as an extended run tank for my Honda's.
I think i paid less than $10 for two of them.

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Captain Bill · 31-10-2015, 13:13

Quote:

Originally Posted by GordMay

Does this help?
➥ OEM Parts

Thanks for the try Gord, but the Oring in question is inside part number 10 in the diagram and as you might notice there is none shown in that position. The o-ring is what actually forms the seal between part 10 and part 7 when they are connected together. It's almost unbelievable that an o ring is not treated as a maintenance part.

colemj · 31-10-2015, 14:46

Ours is a bit over 2 yrs old now and is not leaking. I guess this is a head's up to find some O-rings - however, too late for us for the next 6-9 months now.

Mark

44'cruisingcat · 31-10-2015, 14:52

Other than the fuel connector, how do you find the DF15 to be?

colemj · 31-10-2015, 15:20

I find this an outstanding outboard. We took an anxiety-filled plunge and bought one when it first came out, hoping to not be a pioneer with arrows in our backs. All anxiety is gone now. It out-performs our previous Honda, and every 2-stroke made - while weighing less than our Honda, and about the same as every 2-stroke in its size.

I can't emphasize enough what a difference a computer-controlled direct injection system makes. The fuel injection is constantly being optimized - hit the throttle and the response is immediate; keep a constant throttle and the system goes into a lean burn mode that just sips the fuel.

That last bit took me awhile to realize. I noticed that I was rarely putting fuel in the tank compared to our Honda (which was no slouch in the fuel efficiency department). But our normal mode of use is to jump it up on plane and keep a constant throttle to keep it there - where the lean burn algorithm kicks in.

Compared to all our friends with 2-strokes, I would say we easily use 50-60% less fuel than they do. Our Honda used ~40% less fuel than their 2-strokes, so I would say the Suzuki is ~20% more fuel efficient than our Honda. Keep in mind, though, that our Honda was a 15hp, while our Suzuki is a 20hp. The fuel efficiency difference could be more like 25-30%.

The downside is that I have unintentionally ran it out of fuel because it is so long between tank fills that I simply forget to look at the tank level. We use the dinghy a LOT, and it is still a forgetfully long time between fills of that 3gal tank…

Then there is the blissfully quiet and smooth operation of a 4-stroke. We hear our 2-stroke friends coming from the time they start their OB's, and understand that there will be no conversation in their dinghies when underway. A funny story is that ours is so quiet at idle (and other speeds, but that isn't relevant to this story), we dinghied over to some friends, jumped on board for cocktails, sat in the cockpit with the dinghy literally 6' away from us and never noticed we forgot to shut it off. For the whole 4hrs we were on board...

Now, everyone will go on about computer control and fuel injection, and how they want to be able to fix their engine on a beach with a rock and some seaweed. Let them have their fun. We have had zero issues with ours, while several of our cruising associates with similar aged Enduros and Tohatsus have been working on theirs regularly. Constant carburetor problems, along with other issues not applicable to us.

To be fair though, we have an external fuel filter/water separator on ours. No matter how many times I stress this point, people still decide to run their OB's without one of these. I bet that if these were fitted to all OB's, then 99.9% of all problems would disappear. I know this has been the case for us.

Well, that is our experience.

Mark

**a64pilot** · 31-10-2015, 15:21

Quote:

Originally Posted by 44'cruisingcat

Other than the fuel connector, how do you find the DF15 to be?

Mine is the 20, same engine just computer difference, so far flawless and last year I intentionally abused it by just stopping using it, and left if for the winter fuel still in it etc. for maybe 5 months. Beginning of this year, it cranked on second pull. I did put fresh gas in the tank, and I do use Sta-bil.
I has a SS 11" pitch prop on ours and the dink is very fast, I have a 12" SS prop too, and it screams with one person, but two and groceries etc., it's a little too much prop.
Stock is a 10" Aluminum prop, must be more cup or something on the SS prop, because the difference is more than 1" ought to be. Stock prop it jumps on plane even with four people and bangs the rev limiter if held wide open.

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colemj · 31-10-2015, 15:33

We left ours sitting 5 months in the sun in Guatemala after just stopping it. Started up immediately on the same old gas sitting in the tank in the sun. No additives.

The prop is completely dependent on the boat it is installed on. For example, on our 11'6" 200lb RIB (300lb with the engine - more with fuel, anchor, etc), the stock 10" prop was fine for 2 people (1/3 throttle), took a bit longer to get on plane with 3 (3/4 throttle), and really struggled with 4 (WOT).

We bought a 9" prop and it hits the rev limiter only at WOT with 1-2 on board, but pops 4 people up quickly and runs on plane at 2/3 throttle.

A smaller and lighter dinghy would take increasingly larger pitch.

Mark

**a64pilot** · 31-10-2015, 16:05

I know prop is hull dependent of course but based on how easily I banged the rev limiter, I bought a 12", then found that was too much. I really expected my Zodiac to be a poor performer speed / drag wise it is heavy and has large tubes.
Just letting them know the SS prop has for some reason a lot more "bite" than the pitch ought to account for, so that is I guess either thinner blades, or my thought more cup on the trailing edge of the blade. I know prop brands are different too, mine I think are Solas.
12" 1 person my 3.10 Zodiac will hit 35 kts GPS, now I had to raise the motor significantly as the anti-cav plate is still a little too deep, but the point I guess of a 35 kt dink, is that at 25 kts, it's about 2/3 throttle and quiet and not burning much fuel. The lower RPM sound / feel of the four stroke takes a little getting used to though coming from a two stroke, you think your lugging it, then the rev limiter hits. Darn thing really hauls butt though and I often go on dinghy rides for miles. The 11" prop only lost about 2 kts speed, but gets on plane much better with two people and 100 bs or so of "stuff", that is all I can ever see us carrying.

Anybody got a Zuk, smaller dink and want to go really fast? I have no real use for the 12" prop, unless there are dink races

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Captain Bill · 31-10-2015, 17:09

I've been very happy with mine. Mine has had more abuse than most. My "sealed" fuel tank got submerged in rain water during the flood events about a month ago here in the east. It sucked in a good amount of water but the tank was almost full of gas and i could not see the water. In the bottom of the tank. Being sealed it stays much cleaner than the old style tanks and the water did not have. Any of the tell tale dirt that used to give it away in the old tanks. To make a long story short I managed to fill the entire fuel system with water. To get all the water out I had to disassemble the fuel system including the high pressure fuel pump. There is nothing to be scared of in this system. If you are comfortable disassembling a carb you can easily handle ths fuel pump. It,s a simple 3 piston swashplate pump puwered by a magnetic drive. The unit is sealed with Orings and the check valves are stainless. It was easy to clean out once it was off. I replaced the fuel filter and drained all of the lines. I drained the tank and dried it out and putn in some fresh ethanol gas to scavange any water tha might be left in the lines. It took 4 pulls to get itvstarted the first time. I ran it for a while then took it out for a high speed run.. It worked great and started on the first or second pull after that. I dumped the rest of the ethanol gas into my car and got a fresh tak of ethanol free gas. All is now well except for the Oring. I also added a racor water separating filter in my fuel line.

I just read the EPA requirementsvfor fuel system parts and they are required by law to be warranted forv two years. I guess maybe I'll point that out to the Suzuki dealer that wants to sell me a new connector.

**a64pilot** · 31-10-2015, 18:18

Which Racor you using? I didn't know there was a real small one

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Boatguy30 · 31-10-2015, 18:31

I was going to say, should be warranty anyway. I see they are now offering the 9.9 fuel injected with the 25" shaft. No doubt many cruising multis with outboards will be going this route. I have a charter customer with Yamaha 9.9s, had a ton of fuel related carb problems. Is an open system in salt environment will have issue regardless of care taken. So the 9.9 FI may be a great improvement. I understand there were some CPU issues in the first and second model years, but I assume sorted out by now.

Would be interesting to compare say 2/3 load fuel economy of Yamaha vs, Suzuki EFI