I/O 350 engine - run on 50:1 oil/gas?

[erikgreen]

Hey all -

I'm shopping for stuff for spring now, including stern drive parts and a kicker, and I've got a question on fuel.

Many of the cheaper 10-15 horse outboards out there suitable for kickers run on premixed oil and gas. If I can get lucky and find a kicker that doesn't need that, it'd be nice, but I'm not holding my breath. Probably I won't even have $1000 to spend on this.

My I/O 350 runs on plain 89 octane gas, and I want to run the kicker from the same fuel tank (I'll have a reserve tank this year, but I want either engine to run on either tank for redundancy). So obviously I have an issue. I don't really want to mix the entire main fuel tank 50:1, but I suspect the kicker would die a quick death trying to run gas without oil.

I've seen there are auto-blend systems out there for older outboards, but I've also seen that many people don't seem to trust them or like them.

So, what are my options? I need a kicker that's about 10-15hp, with electric start (reaching over the transom and down to the engine to pull start it is problematic) and has remote controls if possible (I can convert an outboard with some machining work, but it's easier not to). It seems like unless I can afford $1500 or more I can't get a used modern 4 stroke with those features, but there are plenty of older outboards around for $800-$900 if I can solve the fuel issue.

Erik

 

[system-f]

Re: I/O 350 engine - run on 50:1 oil/gas?

Maybe for now you can use the aux tank for premix and kicker only (you could probably run the 350 off this in an emergency if it is 50:1) and when you get the cash for a 4 stroke kicker your problems will be solved.

You could also carry an extra tank above deck until you can afford the new outboard. Since the kicker you are going to purchase will already be properly 'broken in' you probably won't lose much on resale either when you are ready for that newer 4 stroke.

 

[rbh]

Re: I/O 350 engine - run on 50:1 oil/gas?

I think its in your best intrest to just bite the bullet and get a tank strickly for your premix.
rob

 

[John_S]

Re: I/O 350 engine - run on 50:1 oil/gas?

I think its in your best intrest to just bite the bullet and get a tank strickly for your premix.
rob

I'll 2nd that. Seems like allot of specialized fuel plumbing to be able to switch each engine to either tank, anyway.

 

[erikgreen]

Re: I/O 350 engine - run on 50:1 oil/gas?

Well, I'll already have plumbing to permit the main engine to run off any one of three tanks already, so the additional work isn't a problem.

I suppose I could run the kicker off the aux tank normally, and in an emergency I could carry enough oil to mix with whatever's left in the main tank..

How would running on 50:1 affect the 350, when I burn what's left of the premix later? I'm guessing it will run dirty...

Erik

 

[TilliamWe]

Re: I/O 350 engine - run on 50:1 oil/gas?

1st, why does your 350 use 89 octane?

2nd, it'll burn that 50:1 all day long. It'll just smoke a bit, foul plugs, gum up the carb (if it has one), and cause problems later. No big deal though.

 

[rjlipscomb]

Re: I/O 350 engine - run on 50:1 oil/gas?

Why, why, why? It seems that you are trying really hard to screw things up for yourself. Running the oil through you 350 will work but cause problems. Running the kicker without oil will not work. Why not just keep it simple s and use a tank dedicated to the kicker only (for now).

 

[HT32BSX115]

Re: I/O 350 engine - run on 50:1 oil/gas?

Um,


I don't think I'd do that ......

In addition to carbon deposits on those plugs (e.g. fouled plugs) you also can get "fouled" combustion chambers, intake and exhaust valves, tops of pistons, etc. This can result in "glowing" bits of carbon on the above surfaces that can absolutely cause detonation and "Run-on" (dieseling)

Oil (like diesel or kerosene) in a 4 stroke gasoline engine also has the effect of lowering the octane enough to cause detonation at high power settings.

Detonation in a 4 stroke gasoline engine at high power settings (like getting up on plane or high speed runs) can result in burned pistons, burnt valves, and other catastrophic ($$$) failures.

Just find yourself a 4 stroke outboard......problem solved!



Cheers,



Rick

 

[Fishermark]

Re: I/O 350 engine - run on 50:1 oil/gas?

Just find yourself a 4 stroke outboard......problem solved!

Cheaper solution for the 2 stroke kicker:

 

[HT32BSX115]

Re: I/O 350 engine - run on 50:1 oil/gas?

yeah.....I will agree with that!


Except out here on the "Left" Coast.....the Fish Huggers are HOT to ban 2 strokes on lakes!


It's only a matter of time when they ban carbureted 2-strokes altogether ....

 

[erikgreen]

Re: I/O 350 engine - run on 50:1 oil/gas?

1st, why does your 350 use 89 octane?

2nd, it'll burn that 50:1 all day long. It'll just smoke a bit, foul plugs, gum up the carb (if it has one), and cause problems later. No big deal though.

It runs 89 octane because a previous owner let the carb get fouled up, and it's too far gone for me to want to fix it. It runs better with a higher grade gas for now.

I'm going to replace the intake and carb this spring and maybe switch gas then too.

Erik

 

[HT32BSX115]

Re: I/O 350 engine - run on 50:1 oil/gas?

Um,

Higher octane fuel doesn't really do anything for a "dirty" carb.

It's just "Higher Octane" (for higher compression engines) If you're not pinging on 87 octane. It won't make any difference.


Cheers,


Rick

 

[erikgreen]

Re: I/O 350 engine - run on 50:1 oil/gas?

Why, why, why? It seems that you are trying really hard to screw things up for yourself. Running the oil through you 350 will work but cause problems. Running the kicker without oil will not work. Why not just keep it simple s and use a tank dedicated to the kicker only (for now).

The kicker isn't just for emergencies.. without it I can't troll (actually, drag a sonar) at the right speed. So I may end up using it more than the main engine, hence I'd like to not be limited to a small tank. However, I do also need it for emergencies because I'm on a big lake... I have to have a way to run it when the only fuel on board is for the main engine.

The scenario I'm thinking of in the worst case is a crawl back to shore from 50-ish miles away when the main engine breaks down.

Just find yourself a 4 stroke outboard......problem solved!

As noted in my first post, if I can I will. But I don't see many 4 stroke outboards with electric start in the 10-15 hp range for under $1000.

Getting a 2 stroke and using only a separate tank for it for now may work, but I have to be able to run the 2 stroke off the main tanks when the little one runs out (or gets water in it, or something equally annoying).

Cheaper solution for the 2 stroke kicker:

Cheaper yes, but I really don't want an above deck fuel tank for a number of reasons. The main one is that it'd take up precious above deck space and be vulnerable there to water, equipment shifting around, people stepping on it (we go over and around the transom a lot), etc.

If I can find a four stroke or a 2 stroke with oil injection for my price, then great.

No one's commented on the auto blend thing at all... no go?

Erik

PS: The three fuel tanks aren't rube goldberg-y. I have a main tank (53 gallons aluminum) on my centerline, and the other two are mounted on the gunwales for balance. Normally they aren't used except for very long trips on the water, so I have manual valves to go between them.

 

[WOJO 1]

Re: I/O 350 engine - run on 50:1 oil/gas?

I do not want to steal this thread but the conversation is right.
In my case, I do not want to waste 3 gallons of premix, can you run 3 gallons in a full tank, say 20 gallons without issue?

 

[Fishermark]

Re: I/O 350 engine - run on 50:1 oil/gas?

PS: The three fuel tanks aren't rube goldberg-y. I have a main tank (53 gallons aluminum) on my centerline, and the other two are mounted on the gunwales for balance. Normally they aren't used except for very long trips on the water, so I have manual valves to go between them.

So isolate one of the auxiliary tanks and dedicate a line for the kicker. Use your mixed fuel in that tank.

 

[rbh]

Re: I/O 350 engine - run on 50:1 oil/gas?

I do not want to steal this thread but the conversation is right.
In my case, I do not want to waste 3 gallons of premix, can you run 3 gallons in a full tank, say 20 gallons without issue?

If you through 3 gallons of 50 to 1 into a fairly full 20 gallon tank, your motor wont even notice it.

 

[erikgreen]

Re: I/O 350 engine - run on 50:1 oil/gas?

So isolate one of the auxiliary tanks and dedicate a line for the kicker. Use your mixed fuel in that tank.

Okay. When the kicker tank runs out/is unusable for some reason, what do I use?

As a temporary measure it might be ok (as I said above) provided I have a way to run it on some other tank in an emergency.

 

[180shabah]

Re: I/O 350 engine - run on 50:1 oil/gas?

Okay. When the kicker tank runs out/is unusable for some reason, what do I use?

As a temporary measure it might be ok (as I said above) provided I have a way to run it on some other tank in an emergency.

...and it creates a balance issue of you don't keep the saddle tanks at close to the same level.

 

[erikgreen]

Re: I/O 350 engine - run on 50:1 oil/gas?

...and it creates a balance issue of you don't keep the saddle tanks at close to the same level.

True, although I can think of a couple work-arounds... there's usually enough other stuff to move around in the boat that rebalancing if it got extreme wouldn't be hard. Plus there's trim tabs.

But only having one tank the kicker can run off is a problem...

 

[rbh]

Re: I/O 350 engine - run on 50:1 oil/gas?

True, although I can think of a couple work-arounds... there's usually enough other stuff to move around in the boat that rebalancing if it got extreme wouldn't be hard. Plus there's trim tabs.

But only having one tank the kicker can run off is a problem...

How about some way to pull fuel out of the saddle tanks and keep some premix oil on hand and make some premix when its required.
just a thought