TOPIC: a few carb questions

What screw is the high speed and what one is low low plus what are the setings for start up. And how the hell do you get the lower nut on the lower carb off????
I got the setting all screwed up and forgot were I started from. My Dam CRS kicked in.
Mike aka the pirate

First, loosen all the nuts at the same time and take the ones that will come off first. Then, while lifting the carb, unscrew the nut and it will come off. I don't know what type of carbs you have, but, here's the schematic for the 120C. I hope this helps. I think you can click on the picture and enlarge it from there.

I know how to get the nuts on most carbs but the bottom nut on the bottom carb I can see no way to get a wrench socket on it. The belly pan is in the way to get a wrench on the nut and no room for a scoket.
Guess I will have to wait for bill to get on here.
Mike aka the pirate

Mike, That one is a real pain in the butt to loosen. I use a long flat end punch and hammer to loosen. When I tighten I use a combo of wrench, crowsfoot and the final punch and hammer. If all that isn't bad enough wait til you try putting the nut back on!

Sorry, I misunderstood. 4stroke is right. You're gonna have to get a long tool like a punch or screwdriver to "catch" the nut to turn it. My question is, how you gonna tighten it? Would a crow's foot work? If you could show a picture, it would probably help.

I use the crowsfoot and screwdriver to catch the edge of the crowsfoot and pry it up just enough to catch it with the wrench again. After I can't get any leverage to move it is when I go back to the punch and hammer. Anyway you look at it it's not easy unless you pull the powerhead.

pathfinderz1 wrote:

What screw is the high speed and what one is low plus what are the settings for start up.
Mike aka the pirate

In the parts diagram Craig provided #5 is your idle mixture. I'd set it at 1 turn out for startup. It's a fixed main jet so there is no high speed adjustment.

Thanks for all the info. If I cant get the nut off then the carb stays on. Not going to pull the power head just to get that nut.
Mine is a Homelite and my buddys is a Bear Cat. Mine has been running great till it started bogging down at WOT and the same for my buddys. At least he got his to restart and towed us in. I have checked the dieaphem on both fuel pumps and both are pumping good. My next thing to check is fuel lines from gas tanks. Carbs on both motors are staying pumped up. Dam hate working out in the sum here 90 plus here..
Mike aka the pirate

Having problems like this really sucks. It takes away time you could be spent boating. I hope things go well.

If you are talking about the lower carb nut I took a 1/2" box end and cut it way down. Made my life a million times easier.

I was thinking of the same thing and I have about 4 or 5 1/2in wrenchs. My fingers work good for puting those hard to get nuts back on and off once they are lose
Thanks
Mike aka the pirate

First, recommend any owner/operator of these fine old motors get a factory service manual/illustrated parts list/carb and control service sheets.
Yes, either cut down a 1/2" spanner or get hold of one of those little sheet metal wrenches, and bend it.
The Factory Service Manual (here ya go, I can't overstate that the best investment is the factory service pacakge) states to take a 1/2" open end wrench (preferably 12 point), cut to about 2 1/2" length. It's on page 29 of the manual.
Now, I have a sheet metal wrench which I got in a toolbox from a garage sale. I bent it in a vise to 2 1/2" length and it is always placed in my toolbox in the "frustration drawer" with my other special tools! I bent it such that it has a nice U shaped end such that I can press on it with my fingers or lightly tap with a little hammer for those occasional frozen nuts. Little wrench has serviced countless 55's. With that wrench I can pop carbs on/off fast.
I love that thing, it has increased my vocabulary for years now.
I'll get a pic this week.
Factory manual says for initial startup, close GENTLY then open the mixture screws out 1 1/8 turns, turn idle set screw out until it just touches the stop, then in 1/4 turn. Remember, on the mixture screw IN is RICH, OUT is LEAN. It is exactly the OPPOSITE of the 85 mixture screw. I have guys too cheap to buy a factory service manual argue with me on this weekly every single summer. Look at the end of the mixture screw, see where it is? Argument over.
Start engine.
Follow manual instructions from there to set mixture for best idle then slightly rich (IN), then set rpm to 600 (in the water preferably).
Also note which of the three throttle linkage rod versions you have. Also, set the control cables per the factory instructions. Over 50% of the engines I've seen over the last 15 years have the cable and the carbs adjusted incorrectly. Let alone the valves. Just ask MI Dave or OR Dick how nice they idle if valves/timing adjusted first, then carbs done per the book.

Some carbs have linkage slop, some want to idle a bit over 600 (700ish). Well, if that's as good as you can get it, that's what you run. HOWEVER, usually the carbs have junk in them, 90% of carbs are a mess inside. Also, the needle/seat are often swapped on these and are NOT the original. I just setup a set of carbs and the needle/seat in there had an orifice three times as big as the main jet orifice! No idea where he got them. Also, the lower carb gasket didn't have sealing surface for the accelerator pump orifice, so when the linkage was operated fuel bubbled over. One of the reasons he gave up. I know where he got the incorrect gaskets suffice it to say not from me.

Your valves must have clearance set to specs, and your timing must be set to spec, plug/gap correct and your carbs to spec for best idle. And you have to have fresh clean fuel.

NOTE THIS ACTUAL EXPERIENCE:
I had a customer show up here for a tuneup every year for a few years. Year before last I do the normal new impeller, clean cooling passages, impeller, etc. He has an F model and valves don't require adjustment that summer. He takes it and calls saying will idle but will not run at high speed. Calls from out on Puget Sound with family aboard. Says he hasn't touched anything, we ensure vent open on tanks (two brand new tanks one not even filled for the first time, Honda brand), bulb is firm. I tell him take it back to dock bring here. Gets here. Pop carbs off, black plastic debris in bowls. I look in NEW tank with fuel, can see black in bottom and show it to him. I am looking less like a a bad guy at this point. We take other tank out of his jeep, new with labels still attached. I shake it. Rattle rattle rattle. His eyes get big, I'm definitely not a Mxxxxx Fxxxxxx $(@&*$&@)@ at this point. We open new virgin tank, black plastic pieces visible in bottom of tank, small enough to go in fuel line. That's right, off the shelf there was stuff in bottom of tank.
Why I don't know or care, point being you don't know until you look. Period.
While I clean bowls, blow out lines, take fuel pump apart he dumps the black debris out of tank and runs to fill tank. Comes back engine runs perfect with zero adjustments. This happened summer 2010.
Summer of either 08 or 09 I have either 2 or 3 guys call saying engine ran great, died while on plane, won't start. One is pissed off and his wife is on phone with me. I ask if bulb is firm. "No, it is collapsed". Is vent open? No. I think it was 3 boats but can't recall, two of the guys I specifically recall calling me. All opened their vent on fuel tank, used bulb to prime, rest of day was spent cruising.....
I know a guy that bought two bulbs off shelf that had a bad check valve, and I myself got one new off shelf that you could blow either direction, meaning bad off the shelf.
Often it's the basics.

When they are setup correctly they should run like this video. Shot this today on our weekly fishing trip. Because this one is equipped with Pertronix ignition I set the plug gap at .040" The engine ran for 6 hrs just idling away as you see in the video.

Nice scenery Dick!
Is that on the Willamette?
Where's the fish??

Yep, she's idling like a clock all day. Hey look at all that smoke...
How do your plugs look? Did you even look at 'em?

Ok Bill I get a manual but when I lost my leg my kids rearanged everythling around my computer desk and can't find it or a bunch of other stuff I had. Thats been a year now and still can't find things
I know how to set carbs and timing and cables and linkage. All I needed was some number to start with. I have worked on cars most of my life that would be 50 year and worked on outboards for about 15 years. Only dam problem now I'm getting old and getting CRS and thats on it way to CRAFT.
Bill I know your info is for everyone dumb and smart and us smart ones are not so smart all the time
Thanks
Mike aka the pirate

Bill, that's on the Clackamas, fishing was a little slow today we were 2 short of the limit. Fish are up front in the live well, I love that setup. Smoke? The only smoke out of this one is at startup after we've trailered it with the engine tilted. Once that's gone in the first 20 seconds we see nothing for the rest of the day. When they are running like this I don't have any reason to check plugs, just check the hook now and then to see if the bait's gone!