[Hunt n' Fish]

I was wondering if any of you out there are having any difficulty with starting your Yamaha outboards on cold (at or near freezing temps) days. Last season it was a problem for us with a 2001 130 throttle body injection motor.

This season, I thought it had passed, but this morning we had troubles again. At least this morning, so did the guy next to us with one of the bigger Yamaha Saltwater series motors. This lead me to believe this may be a common problem.

Starting is not actually the problem, its getting it to run at idle and engage into foward or reverse. We've attemped to let it run for up to 10 minutes to warm up but the thing just wont run right, until I slam it into gear from a high idle and get moving. After a minute or two of moving it clears out and runs and starts fine for the rest of the day.

Anyone else having this problem, and anyone have a remedy?

 

[615342]

Doughboy

How many times are you squeezing the primer ball. I generally dont squeeze it on real cold days, it floods easy. Cold days takes less gas to get it running. Less evaporation. Are you over squeezing?

 

[Hunt n' Fish]

No squeezing

We never use the primer bulb unless we take the fuel line off, which in this boat is never since the tank is built in. Thanks for the thought though.

The motor will start and run at a high idle, but it is rough. Then it dies when I try to bring it down to a normal idle.

 

[615342]

Sounds like a Merc

Doughboy

Are you sure you dont have Merc

Do you do your own service on the motor. If so I would look into adjusting the idle adjustment, or fuel/air mixing screws, Again with the cold weather the gas/air ratio will be diferent. You should not normally need to adjust these. There is a happy median between 98* days and 28* days. If you do decide to turn small increments 1/4 turn at a time.

Also you are not alone the 115 and 130's are notorious for this problem. I have an 2001 Yami 250 OX66 and dont have this problem.

Since you dont pump the bulb, Have you tried pumping it a couple of times when cold? Do you use the choke?

It should be something as simple as a gas/air thing....

Jay

 

[Hunt n' Fish]

Leaner or Richer????

For the most part we do the service on the motor. Since it runs and idles fine when warm, I would go with the fuel mixture adjustment. Colder air has more O2 so what do you think, lean it out or enrich it?

 

[617110]

From a chemistry point of view

Your right Doughboy,

Colder air does have more oxygen. In that case, one would assume that there should be plenty of oxygen available to fire her up. Thinking of it as a chemical reaction something else must be missing from the equation in order for it not to run right. I would run rich, increase the amount of fuel to combust. Again, this is assuming enough oxygen is available.

However, if you increase the fuel too much you could have the reverse problem. Not enough oxygen to react with the fuel. In this case you will have to back it off a bit...lean it out.

Of course this is theory. It all goes down the drain in the real world.

-B-

P.S. I am not a very good mechanic, but is it possible for the engine not to be getting enough air in the startup?

P.S.S. You said it runs well when warm. You have to ask yourself what all this tinkering around will do or how it will affect the engine after it is warm.

 

[615342]

Leaner is meaner, Richer is safer

Doughboy

OK with out getting to involved here goes

From the sounds of it you need to richen it up. Normally the ECU should take care of it butthe engine can be fine tuned. The ECU will find the optimum range of fuel/air for the conditions ie. humidity/temp etc.

In the summer the air is thinner less air-less gas, In the cooler weather more air-more gas. A motor that is to lean will hesitate when accelerating from neutral idle. And break up at a lower RPM if run at all under load. Higher rpm is dumping in gas so it will work OK. A motor that is to rich will smoke excessivley and foul plugs. Have you checked your plugs? are they the right plugs, they may be colder than you need also.

I am just courious as to why you dont ever pump your bulb?
Also as I asked before are you manually choking the motor?
Are you noticing more smoke than normal when the problem occurs?

Jay

Somoan you gas an A for effort....

 

[Hunt n' Fish]

Jay,

We never use the primer bulb, because the engine always starts right up without doing it.

When I start the motor, I'll bump the trottle up to a high idle, push the key in to choke it and then start her up. When it's cold, I'll choke it a lttle longer after it fires up.

I think I'll try what you recommended by 1/4 turns on the mixture screw. I'll count them as I go and I can always put it back if it doesn't help or it hurts it.

Thanks Brian, My worst subject always was chemistry LOL. I think the engine gets plenty of air, because it starts right up and runs.

Thanks guys

Chris

 

[617110]

Thanks Jay, I gave the answer based on how it made sense to me.

 

[leakyrivot]

in the cold weather it needs more fuel

In agreement on that, in the cold weather, engines need more fuel. That's what a "choke" is all about - with a carb, a choke restricts air flow, which makes the fuel/air mix richen up. With fuel injection, this is all automatic, but occurs just the same. Hard starting is often a problem with a lack of fuel.

As for the primer bulb, what it does is help fill the carb bowls and lines leading up to them with fuel. The fuel tends to leak back down into the tank from sitting (those one way valves in the primer bulb are not perfect) or will drain out of carbs when an engine is tilted; after cranking, the fuel pump probably will re-purge/re-fill everything, but sometimes it needs a little help. If your carbs/lines are half full of air and the fuel pump isn't able to do it's job, an engine could run like crap until the air is purged and the fuel becomes readily available. If you can't resolve it and want some troubleshooting advice, check out www.marineengine.com/discus - there's an outboard discussion board that probably can help.

Jon

 

[Hunt n' Fish]

An easier solution?

Thanks Jon, I'll try the primer bulb next time out. Hopefully this Sat.

Chris

 

[624163]

Hi everyone
There is a coolant temp sensor on all fuli motors that sends a signal to the computer that tells how rich the mixture should be. Be carefull leaning out any adjusments screws (I'm assuming this is a 2 stroke motor) if you richen up the fuel mixture you must also richen up the oil injection mixture. More air/fuel means less oil to lubricate. Bottom line don't play with what you don't know. TO expensive. Let it warm up longer (remember your no longer pulling in 70 degree water) without the choke on. You'll foul the plugs.
Just a tid bit from my 20 some odd years playing with 2 strokes..

Joey