Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

It's in decent condition, new rubber impeller, scraper bar and overall good shape. The guy I bought it from said it had been professionally serviced 2 years ago but had seen little use since then as he decided to hire a plow guy to do his average residential driveway. I could not get it to start after adding some fresh fuel that I brought with me so I offered him $ 40.00 and said OK. - he had it listed for $ 75.00 on CL. I'm pretty sure he left some old, unstabilized fuel in there and it turned into varnish.

I removed the top and back covers and dropped the fuel bowl. It looked like a bad batch of applesauce in there so I cleaned it out and shot the carb with carb cleaner and reinstalled the bowl. It fired up for a few seconds and then died. A good carb cleaning appears to be in order and I'm wondering if I can do this with the carb installed or is it easier/better to remove it from the engine (Suzuki 47P)? I've never removed a carb before but am mechanically inclined and would like to get this operational for next winter.

I remember Borat discussing a cleaning of the jets using wires to remove any build up inside that could cause fuel starvation. I have never done this so any suggestions or tips will be very much appreciated.

   Your carb is filthy, very bad.  I'd poke all the holes with a thin wire, dip it, spray all ports with carb cleaner and air wash it. 

   The float and needle look fine.

   If I remember right, there is a screw in jet at the bottom of the center post by the plastic collar.  Unscrew it and clean it.  Run a wire up into the center tube.  Z-bend a wire and run it up in there back and forth.  Spray in there and look to see if it comes out in the throat.  It coule be your primer is not able to push gas into the throat because one of those areas is plugged. 

   "Trickle" is subjective.  The flow should be enough to replenish the bowl when you are running full speed under load. 

    I'd pull the carb and clean it, but just to get it going for now I'd clean that bottom jet and run a wire up into the emulsion tube and see if can then run.  I'd also try the squirt bottle in the carb as a confidence builder that it's not some other problem like a weird electrical problem once you get it to run.  That happened to me i.e. all the symptoms you had but it turned out that the coil wire would ground after starting.  Remote but making it run with a squirt bottle will let you know you only have a gas problem.

I don't know if the float needle is supposed to be jammed in the slot.   I've never seen that arrangement before.  I'm wondering if It should probably just rest on top of if.  Being jammed in there like that might not allow the float to drop to allow fuel into the bowl.   Generally speaking the float needle just rides on top of the float lever and some carbs have a very tiny spring clip to hold the needle on the lever so that the needle follows the float lever rather than just depending on gravity to make it drop.  Try resting the float needle between the float lever and float needle seat.  See what that does and get back to us.

Have you found a diagram for that carb?

Upon closer inspection of the pictures, it appears that the float needle arrangement might be right.  Does the needle and float move freely up and down?  If so, it's probably correct.  If it's tight and the float doesn't move at the slightest bit of pressure it might not be.  The best way to tell is to turn the carb upside down to see if the float drops with no resistance.  Turn it over to the normal position to see if it drops effortlessly.  If it doe, all is well. 

The carb is still filthy though.  You have varnish all over the place and I'd be willing to bet that the float needle seat needs to be cleaned with a wire, compressed air and a Q-tip dipped in WD-40 followed by a blast of WD-40 and more air.   Find all the tiny holes and feed a wire through them, followed by compressed air.   If the carb doesn't work, it's still dirty.

   There are some carbs where the needle just rests on the top of a float tank (not clipped to it). 

   On his carb the slot is for the needle to fit into, >>loosely<<.  The needle tang is smaller than the width of the slot.  There is a bulb end on the tang bigger than the slot to pull the needle off the seat when the gas is low.   The tang goes on the bottom side of the slot.  His looks right.

trouts and borat: Thanks for the feedback. I'll go get some Berryman's Carb Cleaner Dip and plunk the carb in there for a day or so. I was starting realize that this may be my best option as the carb cleaner spray just did not seem to do a good enough job. I'm off to the parts store (yet again) and will snap some post Berryman's photo's tomorrow.

    Get as much crud off as you can before you tank it.  Once in the basket under the solvent turn the carb with a screwdriver to get the solvent into air-locked passages.  You'll probably see a few bubbles float up.

    The solvent will not clear all crud but even the worse will usually be soft enough to break with carb spray.  So, poking with the wire, carb spraying and air wash still required. 

     Possibly you have the jet removed but in the pictures above there should be a jet at the bottom of the tube in the center of the carb.  If that was plugged it could cause what you have for a problem. 

    Poke up through the center tube inside the main tube.  

    There are holes on the right and left sides of the body which I'm not sure about.  They may be air ports but you can partly poke in there. 

    Looking into the choke side of the throat there may be holes on the right and left side about half way up.  Prod in these. 

   On the manifold side under the gasket there may be 4 holes to poke in.  You may not have those holes on your model.  My Mikuni has them. 

   On the screw head side of the low idle screw there may be two jets.  One is fixed and I think has a through hole.  I can't remember but I think that is a low speed feed limiter. 

   There should be another screw close to the top edge with a spring.  I think that controls air for high speed fuel control.  I think that one is set backed out 1 1/2 from lightly seated (It might be 1).  If it runs poorly tweak it.

The parts store I went to did not have Berryman's so I'm going to try and clean it with wires and carb cleaner. If need be, I'll go to a different store tomorrow and do the dip process. I picked up some brass and stainless steel brushes to help clean the carb and will run wires through as many holes as I can find in hopes that this finally gets the job done! I'll keep you guys posted - Thanks again for your help.

borat wrote:
The float does not move freely up and down. It almost seems like it is spring loaded in the downward position but will move up and down if I press on it without much effort. I cannot rest the needle on top of the float because there's no way it will reassemble in this configuration. I'm going to take a few more pic's with the carb removed from the engine. I just got done doing yet another carb spray, wire brush and wire cleaning so it's a lot cleaner than in the previous pictures.

I've had it for today. Here's a few more after cleaning it again.

Note how the float sits in this photo. It does not move freely but is more spring loaded (down pressure). I can move it up but the spring action forces into the position seen in this photo - even if I tip the carb upside down. Does the needle need to go in a specific way???

See how the needle is positioned - it really can't go any other way.

Looking down the throat.

One more that shows how the float is positioned.

That looks much better. 
  

Don't sweat the bit of spring tension.  It should be offset by the fuel coming into the bowl.  When the float is down like that, the fuel flows in.  As the float bowl fills, the float goes up and forces the float needle into the seat stopping fuel flow. 

Did you get a very thin wire into the holes/galleries going to the venturi and blast compressed air through them afterward?  If the jets, orifices and galleries are all as clean as the carb looks, it should work.

Keep us posted on how it goes.

The float has to be free on it's pin and not pinched on the sides.   Maybe there's varnish inside the float hinge.   Find out what's binding the float.  Pull the pin and take off the float.  The resistance had to be in the hinge area.

The spring could be in correctly or incorrectly, I forget.  Most of the Mikuni carbs I've worked on did not have springs.  Maybe the spring is in backwards.  It does not matter.  What has to happen is the tension has to be small enought that the float alone can overcome it.  You said the flow stopped when you tested that so the tension is probably ok. 

When you have it like you are holding it and the float falls to its stop it's ok.  When you tip it over the float should be level with the bowl gasket rim.  That won't happen with yours because of the spring.  You can pull the spring can check where the flot ends up when the needle seats.

Looking into the choke side there are two internal holes that can be seen in the throat that should be prodded.  

You still have the minifold and gasket on.  Those should come off before tanking.   I think there will be 4 holes in back of the gasket which must be clean and prodded.

In the prior pictures it looked like the plastic bowl stop was cracked.

Do you have the jet that screws in by the bowl stop?

Did you take out the low idle feed screw on the top of the carb and clean it and in there? 

Also, the air feed screw next to it, the black one?   Those usually are brass and have a spring on the screw.  Never saw a black one.  It looks like the type that only has a hair of adjustment.  Maybe they are like the Hondas and have to be broken to get at the screw.  ??  If you can that one should come out and be cleaned and inside cleaned.

The needle does not go in a way other than the way it must go.   The only way it will fit into the hole and slot is the way it is in the pictures.  It's fine.  But it must move freely other than the spring tension.  It should be able to go up overcomming the spring by the force of the float lift from the gas rising.  You'll have to guess that. 

What you've cleaned is external parts which is essential to stopping crud from falling off and plugging something.  What matters is the passage passageways, ports and jets to be clean like the body.  The float looked like it had varnish.  The body looked like it had prior white aluminum powder buildup with a varnish cover on top.  Both are tough to deal with in hard to reach passageways.  If not white buildup then it's probably piles caused by the oil evaporation.  Two cycle gas evaporation can be very weird and many types depending on the gas, oil used and how the buildup happened.

You can test the float action as is by dunking what you have in a class filled with water.  Does the float raise and lower properly?   You can test how soon the float lowers the needle by putting on a 1 foot section of gas line and then fill that with water.  I test needles like that all the time for seating.  Get a class with a mount that is just big enough to sit the carb body on.  Then fill the gas line (pointed up).   You should be able to fill the tube and let it sit for an hour and the level not drop any amount.

SO:

1. Insure the float is freemoving.

2. clean the jet at the bottom of the tube in the center of the carb.

3. clean emulsion tube

4. clean the ports on the manifold side.

5. clean the jets by the low idle stop screw.

6. clean the ports in the choke side of the throat.

7 prod the holes on either side of the body.