Yamaha 70hp outboard idle shutting off

[greglwake]

My 2006 yamaha 70hp outboard motor shuts off some of the time when idling. Only been out a couple times this year since first start up. Engine starts up fine and runs great when in gear, just shuts off some times when in idle. Any idea what I should do to take care of this issue?
Thanks,
Greg

[pstephens46]

Those that can help will need the model number please.

[greglwake]

Model # 70TLR

[99yam40]

probably a fuel issue, as most of the problems are with fuel.
how old is the fuel and do you use any additives?
how long did you put it away for and did you winterize?

have you had any service done to the motor over the years?
filters, plugs, etc?
It is over 10 years old now

[TownsendsFJR1300]

It's a carbureted engine (no lift pump, pulse fuel pump only):

2006 and Later 70TLR Yamaha Outboard CARBURETOR Diagram and Parts

+1 on did you treat the old fuel left in the engine over that time period?

Sounds like your carbs (idle jets specifically) are at least partially clogged...

Can you drain the float bowls and catch the fuel? Your looking for any crap, debris, nasty smelling/looking fuel..

Before yanking the carbs and a good cleaning, you may try some of Yamaha's RingFree:
https://www.shopyamaha.com/product/d...?b=Search&d=34

It's a top end and fuel system cleaner which, IME, works VERY WELL.

As your engine does idle part of the time, it sounds like the jets aren't fully clogged, -YET. Thus, the RF can probably still pass thru those passages.

Certainly can't hurt...

Also, has anyone done a sync and link recently?



.

[Jason2tpa]

As your engine does idle part of the time, it sounds like the jets aren't fully clogged, -YET. Thus, the RF can probably still pass thru those passages.



.

In your experience scott, if a carb'd engine is showing signs of being dirty, a product like RF will clean out the jets so long as their not completely occluded?

I was under the assumption RF, seafoam, etc, are PM products. Therefore using these products after the damage is done is useless. Wrong assumption on my part?

[TownsendsFJR1300]

In your experience scott, if a carb'd engine is showing signs of being dirty, a product like RF will clean out the jets so long as their not completely occluded? IME, yes, usually

I was under the assumption RF, seafoam, etc, are PM products. Therefore using these products after the damage is done is useless. Wrong assumption on my part?

Not sure what a PM product is. Plz read this entire thread, especially post #22:
http://www.yamahaoutboardparts.com/f...e-th28109.html .

I work on alot of small engines, weed eaters, chain saws, blowers, etc. Mostly with Walbro and Zuma carbs that only have VERY small orifices (no jets-just adjustment screws for high and low speeds). Once I get the carb cleaned, I put in a strong dose of RF and let it sit overnight. The next day, maybe 50% of the time, I'll get more RPM's and better performance out of the machine.

I use this Echo tachometer:
http://www.ereplacementparts.com/ech...p-1497076.html

and can often tune another sometimes 1,000 RPM's out of the engine(WOT). I'm VISUALLY seeing the improvement, besides hearing it...

I currently have a Ryobi weed eater on the work bench (waiting for a carb kit) with RF in the top end soaking the rings, piston, head, etc, loosening up carbon (at TDC)

So yes, I do like this "snake oil" (just ordered another quart last week on-line!).

[99yam40]

In that context , I would say PM is preventative maintenance

[TownsendsFJR1300]

In that context , I would say PM is preventative maintenance

Thank you, makes sense.

Jason, yes, it's PREVENTIVE maintenance as well.. Keeps varnish from building up, jets from clogging (with a stabilizer as RF is NOT a stabilizer).

I've never pulled the PU or tank from my 1997 hull..

[greglwake]

Have winterized the boat and boat was stored in a garage. Gas that was left in the engine was treated. Before starting up this year I drained the remaining fuel that was in the tank and started with a fresh tank of gas, also added yamaha's stabilizer and ring free treatment to the gas.
I changed both gas filters and the spark plugs before startup this year.
This is only my second year with this boat/motor.
Don't know when the last sync and link was done.

thanks,
Greg

[pstephens46]

Drain the fuel out of carbs and see what you get as suggested. Bet the gas smells stale. Cleaning carbs is a good place to start on 11 year old motor.

[99yam40]

Usually carbed motors will have the fuel in float bowls evaporate over the months of storage, leaving some varnish/gum siting in the bottom of the bowls.
if any of this breaks loose it will plug things up.
jets and passages are small. if you are lucky the additives will break it up and clean it out before something bad happens to the motor from running on plugged up passages.

I like to take apart and clean them if they are having a problem.
you can do what ever you like
My brothers old 65 Johnson sent a rod out the side of block due to the bottom carb getting plugged up and running it to try and clear it out at the beginning of the boating /fishing season. but that was many years ago

[Jason2tpa]

Thank you, makes sense.

Jason, yes, it's PREVENTIVE maintenance as well.. Keeps varnish from building up, jets from clogging (with a stabilizer as RF is NOT a stabilizer).

I've never pulled the PU or tank from my 1997 hull..

99yam was correct...PM- preventative maintenance. I highlighted your words above to add meaning to my previous question.

If a operator does not regularly add RF or any other decarb agent to their fuel fill ups, what effect will adding it to the fuel after discovering the jets are clogged? Since it's a PM product, but it wasn't used to prevent, is its use also intended to breakdown accumulated debris within the fuel system?

I assimilate the purpose of use of RF/Seafoam to that of coating head bolts with anti-seize lube. It's used to prevent something bad from happening–in this analogy it's seizing. But had anti-seize not been used on head bolts, and they seize, you would not use an anti-seize product to loosen the head bolts. You'd use a product designed to loosen the seized bolt, such as PB Blaster or likewise.

You see where I'm coming from? I might be reading too much into the phrase preventative maintenance, in regards to RF. I've read numerous threads on this forum and others where the operator is asking for advice on how to solve their dirty fuel system problem. A common response is to add RF/seafoam, even double the dose for a better effect.

But this is where I get confused because the fuel system is already dirty, therefore the problem within the fuel system is past the point of "preventative".

Yours and others thoughts?

[pstephens46]

I guess it would be worth a try for a fellow that might not be up to pulling apart carbs. I have seen people soak parts in straight sea foam. Injectors etc. CPostis identified some nasty chemical used at various levels to decarbon engines. So strong in the Yam shop version it was recommended to use a respirator according to Rodbolt. Who knows? I have been trying to clean a couple gas blowers with the 1oz to 1 gallon RF formula. We shall see. Tiny carbs...

[TownsendsFJR1300]

I guess it would be worth a try for a fellow that might not be up to pulling apart carbs. I have seen people soak parts in straight sea foam. Injectors etc. CPostis identified some nasty chemical used at various levels to decarbon engines. So strong in the Yam shop version it was recommended to use a respirator according to Rodbolt. Who knows? I have been trying to clean a couple gas blowers with the 1oz to 1 gallon RF formula. We shall see. Tiny carbs...

The SHOCK treatment is TWO OZ / one gallon of fuel.. And yes, it's worth a shot.

Run it, let it sit over night, repeat. If it's going to work it'll be inside a couple of days.

The primer bulb (likely equipped) has a one way valve that likes to clog up. That section under the bulb is not serviceable(return link to the tank). Pumping that mix thru there sometimes opens it up. Had one recently clogged and was able to save the carb as it did clear out with the shock mix.