Are all 2 stroke outboards unreliable or is it just mine?

[thinwater]

There is an article in Good Old Boat Magazine this month on living with ethanol gasoline.

[RaymondR]

I would not go 4 stroke on a small outboard if I had the choice.

I inherited a 4 hp 4 stroke Yamaha with a boat I purchased and the damned thing drove me nuts. You not only have the fuel problems you have with a 2 stroke but also those related to the engine having a sump full of lube oil and a fair bit of extra weight to handle getting it on and off the transom. After it stranded me a few times I went out and bought a second 2 stroke.

They appear to be a lot more economical on fuel though.

[Simi 60]

I wont run ob's with built in tanks ,anymore, not enough filtration.
Larger obs with separate tanks and in line fuel filters.

We run clean fuel or we think we do through our 2 stroke ob, but the cheap inline filters always get something.
Will be upgrading to a cav style filter mounted on the transom soon, just like the professionals do.

As for 4 strokes, had a guy pop over a few days ago, he had to row home.
Yamaha 4 stroke, e10 was the culprit he reckons.

[belizesailor]

Most problems w small 2 strokes start w a dirty carb. The smaller the engine, the more likely the problem because the channels/jets in the carb are so small they foul very easily. Learn to clean the carb yourself. Its not hard. Keep basic tools on the dinghy for this purpose so you dont get stranded.

Wear saftey glasses when using carb cleaner spray...you do NOT want that stuff in your eye. Ideally gloves too, lots of bad stuff in those sprays, but they work well. WD40 works in a pinch, just not as well. Spraying some sort or magic goop in the fuel/air intake is rarely effective...to really get it clean you need to partially tear the carb down. Careful cleaning jets/channels, use only soft material...like a strand of copper wire.

For storage dont just run the tank dry, DRAIN the carb bowl...typically there is a drain screw for this purpose.

[masonc]

But ane

[masonc]

Buy a replacement carb, for not much money it'll fix a lot of problems

[sailcrazy]

We ran a used 9.9 Yamaha 2-stroke for about 10 years, without issue. We bought a new 15hp Yamaha 2-stroke, and have been using it now for 10 years....all without issue. We typically leave the boat for 6 months each year, we drain the remaining fuel out of the remote tank and run the o/b (without the fuel line connected ) until it quits (draining the carb) before we leave it....then refill the tank, reconnect, pump the bulb hard, and use it the next season. We have had the carb cleaned a couple of times, and replaced the plugs twice....but that's it. Starts and runs every time!

[letoile]

We have a 1981 Suzuki 2hp that starts first pull everytime. Use Shell v-power gas only which is ethanol free in Canada, or our marine ethanol free gas. No issues . Fog it for storage and stabilized the fuel . Spare carb, and Sea foam use are good advice. Those new environmently friendly vent tanks with my Tohatsu 6hp gave me.nothing but grief until I ripped the faulty rubber valve out . Works.perfect.now. just some thoughts.

[bruceb]

I have three of the little Mariner 2 strokes among my outboard collection and have used a couple of them for over 15 years. I expect engines to work properly when operated and maintained, and the Mariners have done their jobs pretty well. That said, they are not nearly as well built as some of the other older 2-strokes and require me to keep a close eye on them to keep them running well. I have a 3.5, 4 and 5. In my experience the 3.5 was more of a toy, the 4 and 5 are almost the same engine and with the 5 having a remote tank I use it the most. The carbs are fair and the lower gear case has a weak prop/oil seal that will probably be it's downfall. I have rebuilt them once, I probably won't bother again. The older pre-import evinrude's and the small yamaha and tahotsu's are built better and are easier to maintain. The Tahotsu's have a better carb that makes starting and low speed running almost pleasant-at least for a 2-stroke.

I have been servicing several late model small Tahotsu 4-strokes for friends and they would be my first choice in that size range. They all have needed to remove the idle screw plug, clean the passage and properly adjust the screw before the engines would start and run properly. Now they are sweet.

I have only replaced one water damaged carb in many years of repair work, all the rest were repairable and usually worked much better after they were serviced. Just saying.

B

[chasmains]

Hi folks, I discovered another problem trying to get my Evinrude 2-stroke to run reliably. It’s an old one, late ‘70s. I didn’t trust mine until I discovered that it couldn’t pull its own fuel. But if I squeezed the priming bulb regularly it would run fine. I put in a new fuel pump but that did not fix the problem. (The motor mounted pump uses intake vacuum to pump fuel with a diaphragm.) I’m guessing the compression ratio is real low at this age. So I installed a cheap automotive inline 12v fuel pump, same hose to fitting size, and run it all the time the motor is used. No more problems. I think it was out of an older Miata. Fuel line pressure is around 4 psi, not a late model fuel injection pump, 50 psi. (I installed a power switch but I sometimes forget to turn it off at the end of the day. Not good for battery life unless shore power is connected.)

[Jhhastie]

I have used 2 strokes for years. Love them.

Here are a few tips. Ignition that uses points and condensers need regular maintenance and retiming. cdi either works or doesn't.

Fuel - use premium hi-test 91 and be ABSOLUTELY sure of NO ethanol. Also use STARTRON to keep you fuel in good shape. It just works.

Change water pump impeller at least every two years.

Good luck.






Sent from my iPad using Cruisers Sailing Forum

[Cpt Mark]

In my area there are a couple of gas stations that sell racing fuel. No ethanol. I go to Indian reservations enroute to buy fuel for the boats I'm on. Pink diesel (no taxes) and ethanol free gas cheap.

[stormalong]

Learn how to clean your carb. These are very simple carburetors. This is a spring ritual for me. Just don't loose any parts - there are only four parts plus the screws on my Tohatsu 3.5. It is simple to take apart and blow out the jet. Fifteen minutes is all it takes. Far easier than a trip to the mechanic.

[Boatyarddog]

Originally Posted by Paramotorgreg

I inherited a Mariner 3.2 2-stroke engine when I bought my boat. At first I was very pleased, because I know that the power to weight ratio of 2-strokes is better than for 4-strokes and I understand that it’s not possible to buy 2-strokes in many places any more. However 3 years down the line I am in despair.... I had the motor professionally serviced and it still fails with boring regularity. I must have taken it to engineers at least 6 times to have the carburettor cleaned, the fuel tank flushed, and just to have it fixed when it refuses to start. We spend a lot of time on anchor so we need a reliable motor, many times it’s a long way for me to row the dinghy and way too far for my wife - especially in poor weather. I am thinking of throwing it away and replacing it with a 4-stroke.....are they any better?

By all means jump to a 4 stroke.
Every 2 stroke we work on in our shop, large or small suffers from the same problems over and over, dirt or bad fuel, or water.
It's not practical to clean your carbs over and over again.
You'll be happy you switched over.
And by the way, 2 strokes are horrible for the environment.
Gas and oil are spewed from these engines regularly.
4 strokes are more reliable.
However, perform regular maintainance: fresh fuel, stabilizer.
Don't leave your fuel can outside during winter, or in the rain.
Use up the fuel or store indoors.
These items work best for our customers.
BTW, have you looked into electric OBs
May be a solution for you.
Cheers,
SV Cloud Duster

[winschwab]

Newer 4-strokes have same problems. I have a 2015 3.5 Tohatsu and 2016 6hp Tohatsu. Always use non-ethanol and stabilizer. Right now the 3.5 won't start and is waiting for a carb job. The 6 runs but only with the choke pulled half-way out. I assume same problem. It has always been finicky starting even brand new. FYI, I believe Tohatsu makes the lower hp Mercury, Evinrude and Nissan motors.