Running lean question:

[emoney]

If my 50hp (507H3D) is "running lean" what exactly are we talking about?
I've heard, in the past, that lean/rich can of course apply to the gas/oil
mixture, but can also apply to a carb setting.

How does one know, for a fact, if a motor is running lean and then how do
you differentiate between a carb adjustment or an oil/gas ratio?

I keep reading these, "Don't let it go lean" threads so I'm wanting to be extra
cautious and "in-the-know". Thanks.

 

[Bifflefan]

Re: Running lean question:

Well I for one have never heard the term running lean referring to the oil/gas mix. It is always used to describe the air/fuel mixture.
Proper air/fuel is 14 to 1 ratio.
The easiest way to test if its lean is to close the choke a little when warm and if it runs better its running lean when the choke is off.
Then you need to find the cause.

 

[emoney]

Re: Running lean question:

Don't take the 'gas/oil' thing to the bank, I've been known to hear voices..lol.

Ok, so if a person does this and it does in fact run better, is it the screw on top
of the carb and do the whole, "hand tighten then back out 1 1/8th turn going in
until is quits" the route to go? Also, are there symptoms to look for while it's
running normally?

What do they call it when your gas/oil mixture isn't right?

 

[Bifflefan]

Re: Running lean question:

Sorry, beyond what I said earlier I really dont know much about O/B's. My guess is that the carbs need an overhaul, or someone that knows them to look at them.
I had one and decided that I needed to get back to the I/O's.
The one I had tho, ran great after I quit messing with it and took it in and had the carbs done by a pro. Man what a difference. Was it worth the 300 they charged, you bet. It started and ran like a champ every time. And after sitting all winter, it took about 30 seconds of cranking and she was running again like it had never sat.

For me, I know quite a few things, 2 strokes are not in there at all.

 

[87blf125]

Re: Running lean question:

i assume you mix oil with your gas and it is not oil injected, mix your gas and oil 50-1. they must be talking about air fuel mixture, turn your screw in till it is lightly seated, then turn it out 1 & 1/4. at that setting my 125 ran rich and loaded up when idoling so i had to turn it in 1/8 more. i would not go less than one full turn out then you may be running to lean.

 

[Frank Acampora]

Re: Running lean question:

You set the idle and mixture while running the engine on muffs. Typically, you start at 1 1/4 turns out from lightly seated on the low speed needle. Ah, Hell---Just read my post on synchronizing carbs and timing from a couple of weeks ago. It explains it all, including on-water testing.