Outboard Decision for a 22-Foot Typhoon Senior

[MHBsailor]

Thanks for your observations Moonshadow. I would be curious to know the year of the 6-HP Yamaha that you borrowed and if it was a 2-Stroke or 4-Stroke? I asked the dealer if the top of the 6-HP motor was any higher than the 2012 4-Stroke 9.9 Yamaha that formerly occupied the lazarette and he said it was maybe a couple of inches taller, but that the gas cap on the 2018 motors is canted to one side so that may help some. Also, he said the height from the top of the mounting bracket to the top of the motor's gas cap was 15-in. Finally, bear in mind the old Yamaha 4-Stroke outboards were significantly smaller than the new model which is just a derated 6-HP model (dealer said it uses a different carb) but is the same size and weight. I won't know until the spring for sure, but I'm sure I can figure something out because I really like Yamaha 4-strokes and the 5-HP Honda 4-Stroke also has a gas cap on top of it too and also weighs almost the same (approx 60 lbs) which is a lot less than the 100-110 lb (depending on the source) 9.9-HP 4-Stroke which was much more difficult to remove and get off the boat while it was on the hard.

[Carl Thunberg]

There is so much conflicting information on fuels, and much of it comes from people who are trying to sell you something. I've grown deeply suspicious of any manufacturer who insists you use their brand of fuel stabilizer. Now I'm hearing that aviation fuel should never be used in an outboard, even though it is highly recommended by small engine mechanics. So, which is worse? Ethanol in fuel or aviation fuel? I have easy access to aviation fuel, and have never had any problems with it.

[MHBsailor]

Carl, what kind of avgas do you have access to? I presume it is for piston engine aircraft because Jet-A and other turbine engine fuels are essentially kerosene blends. JD

[Carl Thunberg]

I get it from my boatyard. I believe they get it from Wiscasset Airport. It is definitely not kerosene.

[MHBsailor]

Hi Carl, as I mentioned in a previous post, civilian avgas is typically "100LL" where the "LL" means "low lead" (compared to the previous formulation), but it still has a lot of tetraethyl lead in it (see the Wikipedia entry for "avgas" at https://en.wikipedia.org/wiki/Avgas#100LL). In addition to being highly toxic, it is readily absorbed through intact skin so chemical resistant gloves are a good idea when handling it in addition to avoiding breathing its vapors. Running avgas in an outboard may void the warranty because it was not engineered to run leaded fuel. More importantly, you may be violating federal and state environmental protection regulations by running leaded gasoline in an outboard because you'd be discharging leaded exhaust into the water. I suggest that you call your state environmental regulatory agency and ask them (anonymously of course).

The only reason 100LL is still around is because most of the gen av fleet uses legacy piston engines that were designed to use leaded avgas and don't run as well on unleaded fuels, so 100LL was a compromise to maintain aviation safety. Modern light sport aircraft (LSA) engines and a few low HP legacy piston engines can also run on auto gas (the latter requires an appropriate Supplemental Type Certificate or STC but I digress).

The bottom line is that your marina may not be aware of the issues that I have mentioned concerning using leaded avgas in outboards - they should be, because if their environmental regulators find out, it could potentially result in the issuance of a Notice of Violation (NOV) for selling avgas to be used in in an unapproved application. I personally plan on buying Sunoco UNLEADED racing fuel which doesn't contain any ethanol (note that some racing fuels also contain tetraethyl lead, but these are not approved for street use).

I mentioned that turbine engine fuels are kerosene blends just for the sake of comparison.

JD

[Moonshadow]

Thanks for your observations Moonshadow. I would be curious to know the year of the 6-HP Yamaha that you borrowed and if it was a 2-Stroke or 4-Stroke? I asked the dealer if the top of the 6-HP motor was any higher than the 2012 4-Stroke 9.9 Yamaha that formerly occupied the lazarette and he said it was maybe a couple of inches taller, but that the gas cap on the 2018 motors is canted to one side so that may help some. Also, he said the height from the top of the mounting bracket to the top of the motor's gas cap was 15-in. Finally, bear in mind the old Yamaha 4-Stroke outboards were significantly smaller than the new model which is just a derated 6-HP model (dealer said it uses a different carb) but is the same size and weight. I won't know until the spring for sure, but I'm sure I can figure something out because I really like Yamaha 4-strokes and the 5-HP Honda 4-Stroke also has a gas cap on top of it too and also weighs almost the same (approx 60 lbs) which is a lot less than the 100-110 lb (depending on the source) 9.9-HP 4-Stroke which was much more difficult to remove and get off the boat while it was on the hard.

It was a relatively new 6 hp 4 stroke yamaha. It had a standard prop. I have a high thrust prop on my Mercury 4 hp 4 stroke and it seemed to be at least as good and possibly better than the standard proper 6hp yamaha. Several variables including wind and current may have skewed my impression. I high thrust prop was under $100.00 and really helped push my Typhoon Senior better and good enough for the money that I am keeping my 4 hp Mercury.

Good Luck

[Skeedeen]

I have a Typhoon Senior that I sail out of Falmouth, ME.

I am planning to buy a new outboard for the upcoming season. It sounds like the Yamaha 6hp is a good option. Can owners of other TyS confirm that the late model Yamaha 6hp outboards will fit in the well of a TyS? Thanks.

[MHBsailor]

Hi Skeedeen, I don't plan on mounting my new 6 HP Yamaha OB until near launch day in May so I won't be able to report back before then. Considering it had a 9.9 HP 4-Stroke Yamaha in it before space shouldn't be an issue. My only concern is if the "long shaft" will indeed be long enough. I had the Yamaha dealer substitute a high thrust prop (at a very modest cost) which should help considerably as others have observed. Perhaps there is another TY Senior skipper who also has the same O/B and could comment before I am able? JD

[TI-JO]

I recently bought a new Yamaha 6 hp long shaft for my Typhoon Senior that I sail on Lake Travis in Austin, TX. It comes with a built-in small gas tank that holds maybe a quart of gas. The problem is that the built-in gas filler cap is about an inch too high for the motor well lid to close. My solution was to just remove the built-in gas tank and filler cap. It comes out as a unit. Then I clamped that tank's gas line so no dirt gets in. After all, it is not a practical size for a sailboat and it is almost impossible to re-fill in open water. Now, I use a standard 3 gallon portable gas tank and the fuel line that came with the motor. It all fits very nicely. That does leave a hole in the motor housing, so to keep dirt out, I used Gorilla duct tape to tape a plastic food container lid to the underside of the hole.

It is pretty simple to remove the built-in gas tank. You will also have to remove the bolt-on carrying handle for the motor as well because it hits the aft wall of the motor well, but that is also very simple. You don't need it anyway since you are not going to raise and lower the motor. I did both adjustments in about 30 minutes.

The motor works well and has sufficient power.

[MHBsailor]

Thanks so much Ti-JO! JD

[MHBsailor]

Unfortunately, even after trying TI-JO's recommendations the lazarette cover still won't close all the way. Mine came with a 9.9 HP Yamaha 4-Stroke so I'm wondering if the mounting beam height is different for other outboards? I've included a photo of mine showing the height from the top of the cockpit sole trim piece. I'm wondering if I should cut a notch in the mounting beam, but would want to first ascertain what the max prop depth should be - Does anyone recall seeing any info on either the width for the outboard mounting beam and/or the prop depth from the factory literature or manuals, either textual or diagrammatic? Thanks! JD

[Markst95]

My olde Tohatsu 5HP 2 stroke, now going on year 23, runs quite decently. Starts on 2nd or 3rd pull and idles wonderfully, though it’s a bit of a shaker...

It pushes my CD22 quite well. It’s Flintstone technology but I think it will run forever...

I have two early 2000's Nissan(same as Tohatsu) 5hp 2 stroke Extra Long Shaft and feel the same way.