Advice for my first Carb cleaning (F2.5) ?

[kaa121960]

I have looked at all the videos I could find, and the one most relevant for my 2005 Yamaha F2.5 was in French (I speak no French), but I think I have the idea. I bought motor used, and it was not used for years. It leaked oil a couple of times due to laying it on the only side not meant for transport, and now I am aware of that caution. The motor will not start, and acts like it is getting no fuel. The only thing I am a little nervous at is putting screws/jets back the same way I find them (not that their current position is favorable to me at this time...). There really isnt any guidance in the manuals that talks about this procedure, and I am trying to determine which screws/threaded-things I need to worry about. perhaps it is only the spring loaded mixture setting. I bought my carb cleaner, my gloves, and my shop towels, and anxious to get started. Any advice for this first time carb cleaning endeavor (besides don't do it) ? Thanks in advance...

[ausnoelm]

First thing to do is do some simple trouble shooting, "acts like it is getting no fuel" needs to be verified, does it have spark? Is fuel even getting to the carb? Don't just pull things to bits on an "acts like"

[kaa121960]

Hi and thank you. I have verified spark, and I will verify the gas ---> carb tomorrow. For that , I assume I can just disconnect fuel hose at the carb (the tank is at least an eighth full).

[Jason2tpa]

First thing to do is do some simple trouble shooting, "acts like it is getting no fuel" needs to be verified, does it have spark? Is fuel even getting to the carb? Don't just pull things to bits on an "acts like"

Makes a valid point. Though carbs still need cleaning since its been sitting so long. I see you've got your carb cleaner, gloves, etc. Did you purchase a new carb kit, including floats? Since you're getting elbows deep with cleaning the carbs you'll def want to replace gaskets, floats, etc.

Carb cleaning is fairly basic. Make sure to thoroughly clean all of the jets by soaking, then blowing compressed air through them. Make sure you can see through each one of them.

[TownsendsFJR1300]

The main issue, should your carb need cleaning, is varnish build up in the idle and main jets.

Their NOT interchangeable. Once the float bowl is off, you'll know how bad the varnish is by how brown the inner bowl is.

Being such a small engine, those jets are going to have VERY, VERY small orifices. They MUST COME OUT (not just sprayed), cleaned etc and you must be able to see light thru them(critical).

I wouldn't bother replacing the float un-less its suspect (you can hold it under water and look for any bubbles-leaks).

If you have an adjustable air screw(with spring under it), gently screw it in COUNTING THE TURNS till its lightly seated. RECORD that # for later re-installation.

If you have a shop manual, compare the turns.


A little spritz of pre-mix thru the carb, when cranking, will try to start, if the carb is clogged up. (most likely the carb ((un-less stored correctly)) probably will need attention...

[kaa121960]

Thanks for all the advice, it has helped !

[kaa121960]

so I have taken the carb apart - I am at least within the float chamber. What it seems to me is that the chamber is bone dry. I was attempting to start it a couple days ago. I am assuming something is clogged between the copper fuel intake orifice, and this chamber. I squirted carb fluid in the fuel pipe (that the the gas tank hose connects on, and also down into where the needle valve sits. How would I verify that I have sufficiently unplugged that channel? Can I hook up the gas tank while holding it in its normal position, and would gas drip through? Can I force compressed air through the fuel intake, or are things too sensitive in that space? Last question, there is a hose coming from a low point in the carb that seems part of "Intake". What is this hose actually for, as it does not connect to anything other than carb (loose end). If it is for 'air', how would air ever enter at that low point? The hose is part (1) of this diagram:
http://yamahamc.partsandwarranty.com...1318827&Page=1

thanks again in advance...

[TownsendsFJR1300]

If I understand your question correctly, you can remove the pin that holds the float on. There is a needle underneath that. Pay close attention there, sometimes the needles "sits in a notch in the float".

The fuel delivery, where your fuel line hooks up to the carb GOES to that NEEDLE opening... You can spray brake cleaner thru there and it'll shoot out.

It's rare (if ever) that clogs up. You can actually leave the float, needle and pin hooked up. Hook up a small tank (I use an old lawn mower fuel tank) and hook up your fuel line to the auxiliary tank.

If you hold the float UP (gently), fuel should not flow. Let it drop, fuel will flow. It IS important that with the float raised, (carb in normal operating position) that when you lift the float, NO FUEL TRICKLES OUT. If it does, it'll also do so on the engine resulting in constant flooding. (That seat rarely leaks).

Most importantly, now that your in the float chamber, find the jets and remove them. Their likely made of brass and may require some penetrating oil to help remove them. Its important to have the correct fitting screwdriver for the jets as its real easy to destroy them if their stuck.

BTW, that link you posted doesn't work(at least for me)..


That needle could have been stuck in the closed position(thus its dry inside). you should be able to see movement with the needle up and down.

[kaa121960]

Thanks for the advice Scott, and understand exactly... When I opened up carb, I did gently check float operation, and seemed to move freely..
I assume if I can set up fuel line as you mentioned, I should also be able to get air through, such that if I put air source at fuel line hook-up, it should get out the orifice where needle valve sits. I will try both to be sure after I clean thoroughly.

I will try one more time in a different way to show that one "intake" pipe I was curious about. It is the hose labelled '1'. There is a screw directly underneath it which I assume is some adjustment related to the opening, I just have no idea what this would do....and BTW - that orifice that leads into the hose was also completely clogged.

here is a shared link I created with OneDrive - hoping it works.

Thanks!

https://onedrive.live.com/redir?resi...t=folder%2cjpg

[cheetah chrome]

An addition to the above pull/clean jets til you can see through them make sure you can blow through their passages cleanly w/ carb spray or air. I've pulled my carbs no less than (4) times in the last 2.5 years (my motor previously sat for a long time as well) and I may have just cleared a passage clog that was missed through the last (3) cleanings because I was so focused on the jets. I'll see once I get it back together later this week but I definately cleared a fuel restriction one of my idle circuits. Since your motor was laying on it's side where the fuel dried up and all the crap that comes may have collected in an atypical location in the carb.

Have fun.

[TownsendsFJR1300]

Thanks for the advice Scott, and understand exactly... When I opened up carb, I did gently check float operation, and seemed to move freely..
I assume if I can set up fuel line as you mentioned, I should also be able to get air through, such that if I put air source at fuel line hook-up, it should get out the orifice where needle valve sits. I will try both to be sure after I clean thoroughly.

I will try one more time in a different way to show that one "intake" pipe I was curious about. It is the hose labelled '1'. There is a screw directly underneath it which I assume is some adjustment related to the opening, I just have no idea what this would do....and BTW - that orifice that leads into the hose was also completely clogged.

]

The pic is super small but it looks simply like a drain line for the carb bowl.
If the bowl is full of fuel and you loosen that screw (should be snug), fuel will drain out of the float bowl. If you look inside the float bowl, on the bottom, you'll see that's a low spot(for fuel to gather).

The screw is NOT adjustable and doesn't do anything but allow you to drain crap out of the bowl without removing the carb (very handy sometimes). You can unscrew it fully and the bowl will drain. Tighten it, and it won't drain(snug it good).

Make sure the needle is ALSO going up and down, not just the float. That's whats actually allowing fuel to flow, or not.

With that being completely clogged, its a major indicator of the rest of the MUCH SMALLER JETS clogged. Pick that crap out, carb cleaner, get it spotless...

This is the closest pic/link, I could get for your carb here in the states (and there are usually some differences):
http://www.boats.net/parts/search/Ya...TOR/parts.html Screw #13 should be the drain screw, there's no nose in that diagram. My F150 has a plastic hose to drain the VST as well

I just cleaned two diaphragm weed eater carbs this am. Old fuel literally ate up one in-tank filter, all the fuel lines, one filter had some slime on it. Got them both running really good and sold one as I was fine tuning it to my neighbor! That unit was payment (got $60) for fixing the other one!

[kaa121960]

That makes a lot of sense to me Scott, regarding that hose and screw deal. I just wonder why Yamaha had that part listed under "Intake", rather than either "Carburetor", or "Fuel". I now definitely have passage in my area of concern, and cleaned all the jets. I am really hopeful.

It was actually fun, and if I fixed the issue, it will be funner

Not to mention a check I didnt have to write.

Thanks for the help again..

Kurt

[TownsendsFJR1300]

Please post back how it goes (or don't )

[kaa121960]

so, I am not experienced at all with outboards....I took it out back, gave it choke, start point with throttle, and nothing....3 times....head held down, I realized one more thing when starting.....open the vent ! BAM !!

Purr like a kitten.....

the world is such a better place with the internet, and people like the ones here, and that make their own instructional videos, taking their own time just to help others...


Thanks again!!

[TownsendsFJR1300]

so, I am not experienced at all with outboards....I took it out back, gave it choke, start point with throttle, and nothing....3 times....head held down, I realized one more thing when starting.....open the vent ! BAM !!

Purr like a kitten.....

the world is such a better place with the internet, and people like the ones here, and that make their own instructional videos, taking their own time just to help others...


Thanks again!!

Excellent!!

Your welcome AND you are now experienced!

If you put your engine up for long periods of time (more than a month), either use fuel stabilizer, or run the engine dry.

Also, DRAIN the float bowl (with your new found screw!) to get ALL drops OUT. Just running it dry will leave JUST ENOUGH fuel to gum it up again...

Just a tip, I've had very good results using Yamaha's RingFree. Its a fuel system cleaner as well as a top end cleaner. Use that, and drain and you won't be in the carburetor any time soon!!

I use it in EVERY gas machine I own...