Tomos A3 Carb Cleaning (Encarwi)

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How to Clean the Encarwi Carburetor on a Tomos A3 Bullet

What you will need:

  • Can of Carb, Brake, or Parts cleaner ($5.00 at local auto or hardware store)
  • Assortment of Metric Wrenches (10mm and 13mm used on this particular bike)
  • Flat Head Screw Driver (small)
  • Flat Head Screw Driver (large)
  • Tin or Container to clean parts in

*Note* You will be doing 95% of the work on the right hand side of the bike (side with the petcock) so set up shop accordingly.

Getting started

This is a Dirty Encarwi Carburetor. It came off of a 1978 Tomos Bullet A3.

First, turn off fuel flow to carb.
This can be done by switching the petcock to the closed position (illustrated below)

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Unplug the spark plug boot from the spark plug.

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Remove the fuel line from the petcock and the carb.
Be sure to drain any excess gas into a separate container. *Note the position and flow of the fuel filter*

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Losen the screw holding the carb to the intake cylinder circled in the picture below:

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Unscrew the air filter clamp from the carb.

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Remove the TOP 2 screws that hold the engine to the frame, as shown below:

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Be sure NOT to strip the bolts when removing them. You will have to hold up the engine to relieve pressure on the bolts while removing them.

The carb should come away from the airbox when the engine tilts. If not, you will need to apply a flat blade screw driver while supporting the engine up, as this is the last bit of resistance holding the engine from tilting down due to gravity.

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Lower the engine a few inches. It should tilt down towards the ground. You need to be careful since the wires that run to the engine/magneto are still connected on the other side of the moped as well as the throttle cable to the carb. It is easy to not see this and pull the wires out like I did, in which case the engine hits the ground hard and you need to re-solder the electrical on the moped.

You are now ready to take the carb off the frame.

Removing the carb

Rotate the carb towards you while twisting the carb. It should come out with little resistance.

Using a pair of pliers, or vice grips unscrew the black plastic throttle top which the throttle cable fits into.

Careful it might pop off since it is pushing down a spring and the throttle slide. Pull it all out.

Remove the cap that went inside the air filter.

Cleaning the carb

Turn the carb so that the brass nut on the left side is facing you. Use a large flat head screw driver to remove the jet, jet holder and atomizer assembly.

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Next, pull out the jet, jet holder and atomizer assembly.

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Now remove the jet from the bottom of the jet holder and atomizer.

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Look through it. If you can't see through it, this is your problem. Spray carb cleaner or brake parts cleaner to clean it, dirty or not. Spray through the atomizer assembly as well. The arrow points to the hole you're looking at.

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place the atomizer tube on the ground and shoot cleaner through the large hole as indicated. Watch out, as it will spray out from the holes around the tube as shown. Continue to clean the jet, make sure its good and see-through.

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Re-assemble the jet into the jet holder/atomizer tube and set it aside for now. Next, remove the banjo fitting from the top right side of the carb (not shown). Remove the two screws that hold the bowl cover on.

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pull off the cover and remove the float and float needle assembly (which, by the way, looks suspiciously like a fishing bobber- more on that later)

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Next, place the bowl cover on the ground and blow through the needle seat as indicated. Be sure when re-assembling the carb to replace the gasket that is on the underside of this cover. I couldn't find one for sale so I cut this one.

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Now blast the gunk out of the float bowl. You might have to get a rag and clean all the junk out of bottom of it. Make sure the bowl is as clean as you can get it. It will smell like gas, but should have no sediment in the bottom.

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Next, blast some cleaner through the throttle tube on the top of the carburetor as shown. Make sure to get some in the small brass tube that is barely visible in this cellphone quality shot.

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Pull off the air screen as shown and blow cleaner through the back of the carburetor. Remove any gunk from the back here as well. Spray cleaner on the screen as well.

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Put the needle/float assembly back in the bowl, align the cover up with the needle so that the needle goes in the seat and put the cover back on. Put both screws back in all the way. Put the banjo fitting and screw back in- DO NOT OVER TIGHTEN as the fragile plastic banjo will break and leak gas everywhere except into your bowl. Put the jet holder/atomizer/jet assembly back in the hole on the left side of the carburetor. Screw down until just after hand tight.

Throttle asembly

Place the spring on top of the slide (not shown). Put the throttle cable back in the hole in the center of slide (not shown) Put the slide in so that the notch on the slide lines up with the key bit on the slide.

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Put the spring on top of the slide and tension it while putting the plastic cap.

Put the air screen in and make sure it sits in snug. Reattach to the bike's air filter and intake. You're done cleaning it! now reassemble the bike!

The Encarwi as a Carburetor

Its hard to tune, hard to clean, hard to get to, has no spare parts as far as I'm aware, and continually leaks. The float has no rubber on it to seal good, so if you ever leave your fuel on its going to leak. Best option is to replace this one with a secondhand Delorto 14.12 and associated intake as soon as possible. Everything will run better with one, trust me. Check the buy and sell section of our forum for cheap used ones.

--Young maker 14:04, 12 April 2015 (EDT)