Mercury 3.5 HP Outboard Junk?

[Lasata]

My 3.3 Merc was a pain last winter, but after cleaning out the GUNK from the carb bowl it has been running GREAT! I've had it for quite a few years now, and this last winter was the only trouble I've had. I'll blame it on the gas in the Keys for now.

[dugout]

If E-free gas is not available run it on AVgas. Find it at any airport. Small motors LOVE AVgas. It's tank stable for 5 years by specification, I have been told. Avgas is the closest thing to the gas we used to enjoy before all the changes.

[pbiJim]

Originally Posted by dugout

If E-free gas is not available run it on AVgas. Find it at any airport. Small motors LOVE AVgas. It's tank stable for 5 years by specification, I have been told. Avgas is the closest thing to the gas we used to enjoy before all the changes.

AVgas comes in a few different flavors. There is red, clear, purple, green & blue. The one that you want is blue (aka 100LL). It's the most common type of AVgas that is not jet fuel.

The only issue is, if you run AVgas, you should also run Aeroshell oil in the crank case. The keytones & other solvents in AVgas tend to eat up regular motor oil pretty quickly.

100LL runs well in most gas engines that don't have an oxygen sensor, a catalytic converter, or a turbo charger.

Avgas is also a real good carb cleaner.

[MarkSF]

AVgas has lead in it, so it would be highly irresponsible to use it in a marine setting.

[pbiJim]

Originally Posted by MarkSF

AVgas has lead in it, so it would be highly irresponsible to use it in a marine setting.

100LL = 100 octane Low Lead. It's basically the unleaded version of AVgas. The purple & green versions have a ton of lead in them. I think that the red stuff does too.

[dugout]

Red, 80, is all but gone in the US. 100LL is no worse for the planet than pump gas but your outboard will sure like!

[pbiJim]

Originally Posted by dugout

Red, 80, is all but gone in the US.

I still see it every now & then out in Iowa & Minnesota. It's still sold in a few areas where people continue to run old time low-compression crop dusters. I do agree though, MOgas (red) is getting pretty hard to find in most places.

[thomm225]

I use the special 87 octane they sell at the local 7-11. It works great with my 5 hp 4 stroke Merc..........

The carburetor has never been cleaned, plug hasn't been changed, I don't run it dry after use and have had no trouble these first 100 hours or so.

[pbiJim]

The next small outboard I get will probably be one of the propane powered ones made by Lehr. Hopcar (a member here on the board) sells them & seems to support them pretty well.

[PDA1]

Thanks everyone.

Whatever engine you have that's reliable is perfect. Even one that's not reliable, but you know how to fix, is good too.

There were just too many bad comments about the Mercury 3.5 to warrant getting it.

We bought a Yamaha 2.5- $740 including tax.

Started first pull. Have used it for 2 days now and love it.

Light weight, easy to carry, simple.

It pushes the dinghy fast enough for my liking and it sure beats paddling!

[thomm225]

Originally Posted by PDA1

Thanks everyone.

Whatever engine you have that's reliable is perfect. Even one that's not reliable, but you know how to fix, is good too.

There were just too many bad comments about the Mercury 3.5 to warrant getting it.

We bought a Yamaha 2.5- $740 including tax.

Started first pull. Have used it for 2 days now and love it.

Light weight, easy to carry, simple.

It pushes the dinghy fast enough for my liking and it sure beats paddling!

I hope it works out for you, but it appears from the summation of this thread that the small carburetors were the problem on the very small outboards ................say 3.5 - 4hp or less.

Maybe Yamaha uses a bit larger one on their 2.5. I do know that many waterman on The Eastern Shore of VA (crabbers, oystermen, etc) swear by Yamaha and would use nothing else..................

[PDA1]

Laughingly- if this one fails....I'm putting a VW Rabbit Diesel engine on the thing. It'll either plane, sink-the-dink, or get 45 mpg. One thing's for sure- it'll never fail.

I've noticed how people treat their engines- badly. For example- "you mean you have to change the oil"? Stick it in the garage with untreated fuel, etc.

I swear AT crabbers.

[bloodline]

Had a merc 3.5...

Couldn't wait to get rid of it.

Found a Yamaha 3hp, 2 stroke. My 8 year old can crank it, cold.

The Yamaha has a fuel filter that is inside the gas tank. It's held in place by the fuel line.

The merc has no filters. Needs one, badly. The pilot jet is insanely small.

I also have a street legal legal 2 stroke dirt bike. These small "Eco friendly" 4 strokes are just not my cup of tea. I reckon I've poured gallons of gas on the ground and in the ocean trying to start dead 4 strokes.

[Lake-Effect]

Originally Posted by bloodline

The Yamaha has a fuel filter that is inside the gas tank. It's held in place by the fuel line.

The merc has no filters. Needs one, badly. The pilot jet is insanely small.

Our Suzuki 5hp also has an inline filter. I agree that filters should be in every outboard. (has anyone added one to the 3.5 Merc?) It would certainly help trap particles that could block a jet, but I don't know if that's the answer to gum formation in the carb.

[searenity38]

I had a 6hp Tohatsu and it never failed me. Ever. Keep in mind that Tohatsu makes all the OBs for Mercury under 9 hp. I also have a 3.5 2 stroke Merc and I have no problems with it either. Now I have inherited a 3.5 four stroke Merc for my newly acquired HC38. I'm not expecting any problems. Just make sure you periodically flush with fresh water.
Joe
SeaRenity