Cleaning the Sammy Carb

Quote from: Whitfield on Thursday, June 23, 2005, 11:32:38 AM

Is your sammy running poor?  Does it have near unbearable hesitation and flat spots?

Just late last week mine took to having a bad stumble on anything much above an idle and continued until way up in the RPM's.   This truck ran flawlessly just days earlier and would still idle and run fine above 3k - wide open.
With the carb being able to feed High RPM's smooth and continuously then we know it is not a fuel delivery problem.  It is using the most fuel at High RPM so it is flowing efficiently from the tank to the engine.  Also smooth idle and with no variation or miss tends to help rule out vacuum leaks and ignition issues.  At this point I knew I had a blockage in the carb. 

      I have tried most of the pour in the tank carb cleaners and tried most external carb sprays.  I have not had good results.  This is not to say that they should not be used but rather their is a time and a place.   If a passage / jet is plugged then it has no vacuum / air flow.  With no vacuum then it has no way to pull the cleaner into the area it is needed.   I always begin with a bottle of Sea foam or Gum out.  You generally want an in tank additive that cleans varnish and removes water.  Run this thru at least one tank, I usually half the bottle and stretch it into 2 tanks.  I try to run at least a tank full of fuel and cleaner thru before I begin cleaning or repairs.  This way I hope to break loose all the debris and make cleaning easier.  ALSO If magically (As is often advertised) the problem corrects it's self then I've saved a step.

      Once I've run a tank or two of fule and cleaner thru the sammy and the carb problem still exist then I know it is time for a tear down.  This job is not bad, It usually requires no consumable parts and can be performed in less then two hrs.  Plan on a long afternoon if you've never been into a carb before and this is your first time.  Also If you are not carb suavy, I can not stress enough how valuable the factory service manual is when performin this type of service.  Get one and read the section on carbs 2 or 3 times first.   It may help you correct a problem that is not related to cleaning.   

     Opening up and clean the stock samurai carb is actually easier then removing the carb from the intake and changing it out (For me anyways / intake on the truck )

These are the tools I used, Not all are necessary but this is the pile I had by the truck when I was done. 

To begin I remove the PVC and Valve cover breather hose and and the small vacuum line from beside the PVC to the tin air duct (The big one on top of the carb that the air goes into the engine thru)  Once these are out of the way you can get a better picture of what is below.

It may look a little over whelming but it is nothing to fear.  You do not even need to know what the items do, But it would help.   Basically we are looking to remove the (5) phillips head screws in the carb top remove it clean all the passages above and below and then reinstall.  Unfortunately it is a little more complex then that. 

First I usually remove the Accelerator pump arm this is the big flat head screw on the passenger side.
Just remove the screw noting how the washer and lock washer are situated and pull the arm pin from the pump and let the arm hang down beside the carb.  Next we look at removing the throttle cable plate screws.  Their are two, One is the the passenger rear of the carb top and the second is just below it on the side of the carb.  Both must come out to remove the carb top.  The lower one is often hard to break loose and I will leave you to your own devices.  I often use a small chisel and tap the outer edge of the screw thus saving the head for reinstall.  I have noticed that most of the carb screws have a provision for a flat head screw driver.  This can make things easier too as with the craftsman set I had on hand I could use a 1/4" wrench to assist and break loose those stuck screws.    Use screw drivers with good tips and do not strip the screws   Their is a stuck screw removal how to written else where here.   If necessary go back and reread it for further assistance.  Nothing here should have Loc-tite but the bond between steel and aluminium can often be as strong as if loc-tite were used. 

Next I remove the EGR Vacuum switching valve and the 2 screws the hold the rear accessory plate.  Move the plate to the rear so it is out of the way but leave everything still plugged up.  Then I will remove the two cooling lines.  Yes Cooling lines.   The Sammy's choke depends on Coolant to measure temperature.  When the coolant warms up the choke comes off.  I Usually plug these with some drive shaft bolts or what ever else I have laying around.   Plug them and set them out of the way.  Next you need to pin the choke linkage.  This is necessary for the link age to clear the fuel shut off valve.  Yes, Fuel shut off valve.  The sammy has one so that when you kill the ignition it also kills the fuel.   I used a screw driver and pried the linkage into place so the holes lined up and thenpinned them in position with a small allen wrench (Yes I used standard allens 

).  Next you need to remove another hard to reach screw, This one is on the back drivers side on the lower edge holding the two plates together.  I've only got a bad picture of it. 

Lastly I remove this vacuum line and this screw up top here on the drivers front. 

You are now ready to remove the carb top.  I find it best to tap and wiggle it to break the gasket loose.  You will be pulling the accelerator pump out with the carb top so watch the passenger front side for it.  I usually lift it about 1/2" and then work to free the gasket.  I have so far been able to reuse the gasket on each one with nearly 10 done so far.  Some gaskets will look better then others and if you would like a New one I'm sure Brent at Trail Tough or Suzuki dealer can provide one, But if you are careful the old one can be reused. 

This is what it looks like with the top removed.  The float bowl here is very clean,  This is how it looked when I opened it, As you see gas is still in the bowl.   I like to see it with the fuel still their so I can check it for trash and water.  Their are two drain plugs on the front of the carb if you go for a swim or otherwise find it necessary to drain the bowl. 

Next we will look at the passages and jets.  This is where most problems lie.  A good can of carb cleaner and a small piece of wire will help greatly.  For cleaning wire I usually pull a strand from my bench grinder.  It is small enough and stiff enough to get the job done.  If your float bowl is gummed up dirty and varnished you can use a piece of stranded wire (Speaker wire, Small 10 gauge power wire ect)  strip the insulation feather the end and use it a a small wire brush / cleaning device spinning it in between you thumb and fingers. 

I will usually clean the bowl first then move on to spraying Carb cleaner thru all the jets and passages.  Here the FSM can be of great assistance giving you details of what provides what function.   I usually just clean them all.  I begin with the red tube on the carb cleaner and good eye protection (Carb cleaner in the eyes burns / might keep a small bottle of water around for flushing the eyes just in case.   I had to dround my head in the Pool yesterday)  Spray the carb cleaner thru each jet & passage.  Check for flow, it should spray out with force,  not dribble.  If you find a plugged passage then work it clean with the wire.  Also remove any trash or debris as you go.  I removed the plugged jet in my carb and cleaned it individually then cleaned the passage below.  I found a small piece of silicone thread sealer pluggin this jet.  Unknown how it got in their.  I will usually go thru all the jets and air bleed screws with the wire just to make sure they are clean.  Often times working the wire carb cleaner and compressed air at the same time.   

Next we need to look at the accelerator pump.  This is actually a simple set up with dual check balls.  One is on the bottom of the accelerator pump its self.  This lets fuel into the pump chamber and then closes it off whenthe piston is compressing the fuel to squirt it out.   The other ball is in the base of the secondary chamber.  The pump piston forces the fuel thru the passage on the lower right and past a second check ball  (this is the one famous for sticking)  this ball is held in place by two funny shaped pins with an Ink pin looking spring in between.  This ball closes the passage after the fuel is compressed and forces the pump chamber to draw the next charge from the float bowl.  The problem lies that when a Sammy sits for a few years and the fuel varnishes both balls are stuck on their seats and they sit their with spring loaded pressure on them.  The varnish will sometimes glue the balls in place making the accelerator pump not function.  It is best to remove both balls the spring and two pins, and theroughly clean the chambers.  Be careful with the balls as compressed air or a shot of carb cleaner can send them flying.  Also they are not magnetic so I will have to leave you to your own devices as to how to remove and clean them.  I shot  them out with compressed air, But gum on a stick or some other ingenious trick would be necessary to do it safely and not loose the parts.   

Once you have the carb base all cleaned up look at the top.  It has jets air bleeds and passages too.  The big fuel pick up in the middle often attracts crud clean it up as best you can inside and out.  Also check out the needle and seat.  It was most likely functioning properly or your Sammy would flood (Spill fuel everywhere) or starve for gas and not run.  Just check it over close and the float itself is hung with an uncaptured pin.  In handling and flipping it around this pin can come lose and cause the float to not work correctly.   This would cause the carb to flood and spill fuel into the charcoal canister upon start up.

Carefully reassemble the Accelerator pump assy.  The two pins have marks the one with the dot on the top sits down on the ball, next drop in the Ink pin like spring and then the other pin.  The accelerator pump spring has a small loop on th e bottom end to capture and apply pressure to the ball in the bottom of the pump chamber.

Reassemble is the reverse of taking it apart.  Be careful slipping the acell pump piston back into the chamber, I usually spray it with WD-40 to help it slip into place.  Just be careful to get the gasket back in place correctly and check for any vacuum lines you removed or disturbed.  Vacuum lines will often crack or break on the end opposite of where you were working causing more unknown headaches.

Now before you start it up and test it out, We need to change the fuel filter.  Begin by opening the fuel cap, relieve the pressure.  Now change the filter, often time it will be the OEM stock one from 1987.  I allways like ot cut open the filter and see what it has picked up.  Most all of them will contain water from condensation with in the tank.

Now start the truck and check for fuel leaks and coolant leaks (Remember you opened the cooling system).  Top it off as necessary too.   

Not complete as I had some pics with Diagrams made thru MS Paint. But basic stuff is up again. I'll try tio clean it up later when I haven't been up 20 hrs.