Home Forums Hunting & Shooting Hunter's Campfire Two-stroke outboard experts....

That's where I'd start. Cheap. Easy.

Not. I've run oil slickers for 50 years with fewer (if somewhat repeatable and i know those!) problems up here in remote country, than my Yamaha f-40 has had in the last 9 ( exclusive of self-caused problems) And Yamahas are supposed to be the best 4 strokes going. I'm still learning about 4-strokes, too- mostly that they are heavy as hell and require shop service. Mostly. I'm still learning 4-stroke, admittedly.

I have such trust in my f-40 which has failed to get me to my remote cabin (700 miles OW, driving and boating) the last two times, that next year the reliable '96 2-stroke will be in the bottom of the boat in case I need it to get back up the main river to the landing. And I can work on that myself, even on a sandbar, without all this new electronic crap adding to the weight and unreliability. I'll just stash it in the brush before proceeding the 15 miles up tributary to my cabin. Don't need the 125 lb handicap in weight for that portion.

As mentioned in my OP, only ever run ethanol-free gas, engine starts like a champ, throttle response is fine, just dies at idle.

Spark plugs are brand new, fewer than 5 hours.

Anybody that thinks a carbureted two stroke is more reliable than a fuel injected four stroke is smoking some good stuff. They might be lighter and easier to work on but the trade off is that you do have to constantly work on them.

My post was in jest but the fact shouldn’t be lost that those claiming two strokes are so reliable are on a thread started about another broken down two stroke.

Everything else is arguable, but four strokes have brought a huge leap in reliability to outboards.

NEVER... I wrote the company years ago ...the new bottles have a no use in 2 stoke ...red one is OK...

Lol I been down this road before I got a four wheeler that will start and run like no tomorrow and then it won't start you'll check fuel you'll check here you'll check everything guess what you put a new plug in it and runs like a top until it does it again even went to my four wheeler and my outboard repair guys and they said yep too they say after a couple hours of pulling on a big old sled that you learn faster to just change the plug... the third time of 6 months that it happened to me I even have the NGK plug sitting on my desk at work to ship back to them and ask them why .......and no it ain't nothing else on my wheeler that's broke you can give it ethanol you can check everything change the plug boom it'll start .....put the other plug back in won't start put the new plug back in boom it'll start unbelievable but....

Maybe a slight air leakage somewhere? Check all your hose clamps and fittings. Or above suggestions. Could be at a higher rpm it is suckng enough gas to overcome.

I once had a similar (opposite) problem, running wide open down the middle of the river. The motor started missing and losing power. Turned out the rubber gas-line feed from the hose connector toward the carb had broken a plastic clamp (old and deteriorated), and was sucking air. Idled OK- enough to get me to shore and find the problem.

I had cleverly left my SS wire out of the tool box, but found a piece of white store string in the bottom of the boat. That got me to my cabin, where I did have some wire, replaced with a hose clamp when I got home.

]
This!!![/quote]

[quote=Crow hunter

Not.

I've had fewer problems (but lots of repeats - water pumps, fouled plugs mostly) with 50 years of oil-slicker 2 stroke use than I have had in 9 years of 4 stroke. Not counting self inflicted wounds... . 100+ pounds lighter, and I can work on them, even on a river bank, rather than the nearly mandatory shop service and 2 month wait for my 2005 Yamaha f40. Plus, it is readily removable from the boat if need be. A 260 lb 4 stroke is not. Oh, I coluld do it in the bush , if I had to.

That remote steering and shift on the 4 stroke Yamaha is admittedly nicer on neck, shoulder, arm than my 30hp 2-stroke '96 tiller Evinrude , which will be a passenger in the bottom of my boat on my next try for my remote cabin, 700 miles OW from here. It is reliable, and does as well with the prop as the 40 does with the jet (making it about a 30), said jet being handy during low water off the main river. The Yamaha F40 has failed me on the last two attempts, near the far end of the trip. 1400 miles RT for nothing pisses me off!. 30 gets brush cached at the mouth of the side river 15 miles downstream from the cabin in case I need motive power for the upstream portion either river.

I don't need that 130 lbs of extra weight (Motor, tanks, hoses, water pump, plugs) on the final segment to the cabin- I can (and have) floated/rowed back to the mouth. I really don't like the extra weight, but it would not have been "extra" on the last two attempts.

This guaranteeds the F'kin-40 will run like a top all the way!

I see people running 40 year old 2 strokes where I live all the time. I think you are sucking air through a connection or have some trash in the fuel system somewhere.

Had the same thing happen to one of mine. Hasbeen

Got to have fuel too!


Jerry

Idle fuel circuit in the carb is plugged as a couple others mentioned. Easy and cheap fix with some carb cleaner and a pin to get it cleaned out. Possibly even free if you don’t tear the carb gasket.

The fuel line connections are frequently a problem if it idles for a little while and then dies. Any little air leak from a stiff hose or a chewed up o-ring will cause the pump to suck air instead of fuel. A weak pump makes it worse.


Jerry

Are you running the fuel line through a fuel/water separator? If so, bypass it and see if there is any change. New fuel line and a bulb would be the best start after thst.

Lots of good suggestions (and a few that only rate participation awards) which support and expand on my own thoughts. Thanks to all. My plan, going forward, is 1. replace fuel line (it’s almost 20 years old anyway and owes me nothing.) 2. If that doesn’t do it get a fuel pump rebuild kit and replace diaphragms. Meanwhile, of course, check for any possible air leaks in system. I’ll report back .

2 strokes are pretty simple
I have never had to work on my 2 stroke outboard much only the 4 stroke
Is it carb or fuel injection

I'd bet dollars to bullets that you have crap in your carbs. One other thing could be your carbs could be out of sync. They'll run when you put the screws to them but won't when putzing around at the ramp.

I thought that I was the only person who wasn't an expert on two-stroke motors.

I had a similar problem on my 2000 Johnson 25hp and just adjusted a screw on the carburetor. It's a good idea to change the hose/bulb every so often too.

Problem has been solved and it was very simple.

I figured I'd start with a new fuel line, so off to the local Yamaha dealer, got a new fuel hose and went back to try it out. It didn't fit my tank. It had the wrong type of connector at the tank end.
Back to the dealer: "This hose doesn't work for me, wrong connector on the tank end."
Parts manager: "What kind of tanks do you have?"
"Yamaha tanks."
She took me around to look at all the hoses they had with connectors for Yamaha tanks: "Nope, nope, nope....come on out, I've got the old one in the truck."
Soon as she saw the old one, "Oh, those were recalled in 2014. Yamaha would provide replacements for your fuel pick up and give you a new fuel line as well."

We went back inside and she called Yamaha. They said give then the motor serial number and, even though long out of warranty, they would send replacement parts (they didn't have any in stock at the dealer. Only problem was, they were sending from Japan and it would currently be about 2 months. I don't want to wait two months. She went online and found that, regionally, there were three in stock, one in Savannah and two at a dealer in Columbia. Great, I have to go to Columbia Thursday anyway. She gave me the number of the dealer in Coumbia as well as the part number. I called, yep, they had them. Offered my CC number to hold for me until Thursday. "Just give me your name and I'll hold them for you."

Picked up the new fittings in Columbia yesterday. Refitted my tanks with them this morning, tried it out....runs like a champ. Will idle forever now.

Apparently, the old style, when they got a few years on them would get kind of aged and wouldn't seal well. That's why under throttle, there were no problems, the fuel pump was sucking hard enough to keep the connection tight enough that id didn't leak. Get down to an idle, and it would loosen up and start sucking air.

I like simple solutions....no carburetor, fuel pump, timing, spark plug, reed valve or other issues...just replace the old connectors with the new style.
Again, thanks all for thoughts and suggestions.