Wednesday, 10 July 2013

Honda 2.3 outboard carb clean

Just thought of this post that I wrote a good while ago, and that it would make a useful blog entry.... so here goes.....

My Honda 2.3Hp outboard has been running somewhat roughly recently, and had started to need excess choke in order to keep it running.

A good check over was in order, so I brought it home to check it out.... 

It seems to be a common issue from previous threads on this forum, so I suspect i'm not alone in having this problem...

so.... last night I removed the carb, and discovered it to be really quite dirty, and after a good clean out it ran as sweet as it had ever done.... and thought it would be worthwhile sharing what is involved in detail for those less comfortable just getting stuck in, but willing to give it a go with a bit of guidance....

1] Remove the cover. This is done with the black rubber strap at the rear of the cover. 

2] You will see three bolts that hold the starter cord (recoil system) to the top of the engine. It is worth undoing these three dome headed nuts, and removing the recoil unit, so that the whole cover can be put aside for better access to the engine

3] On the rear of the engine at the right hand side you will see a black plastic 'U' shaped item. This is the air intake. On top of this is a small clamp that holds the throttle cable in place. Loosen this clamp (don't undo completely), swing the small metal plate out of the way to free the cable and remove the cable from the clamp.

4] Now there are two bolts that hold the air filter on. they are on the right hand side, and towards the rear of the plastic air intake. The lower bolt is recessed a couple of inches, so you will need a socket wrench with an extension on it to reach the bolt. You will need a 10mm socket. Undo these two bolts taking care, and withdraw the two bolts one at a time. remove the air intake and place it in a clean location. They also hold the carb onto the engine, so make sure that the carb does not fall off. (it probably won't)

5] Carefully wiggle the carb by hand (don't use a lever or a hammer - its a delicate component!), and once lossened, lift it clear of the engine.

6] The choke cable and throttle cable will still be attached to the carb. maneouvre the carb so that these can be taken off (they have a small dog leg on the end of the rod/cable and just need orienting correctly to detach them)

7] Once the carb is clear, then take real care not to damage the paper gaskets that ensure an airtight fit to the engine and air intake. Unless you are unlucky, then these will be fine to reuse. If they get damaged, then spares are readily available, or you can make new ones from gasket material.

8] At the bottom of the carb is a metal 'bowl' with a 1.5" long pipe as part of the component. This 'bowl' is held in place by a single 10mm bolt. Undo this bolt (remember to take care of the gaskets!). Note the orientation for reassembly. Once removed, then you can start cleaning. 

9] In the bottom of the carb is a metal tube (that the bowl was bolted to), this has a very small hole in the side of it. This must be clear as this is how fuel enters the rest of the carb.

10] Next take a fine wire (soft as you can find) and gently (very) poke it through the hole exposed inside this 'tube'. This is the main jet, so must be clear, but is also very delicate, so take care.

11] Hold the choke and throttle fittings open (where the cables/rods connected) and two round 'flaps' will rotate to show you the main carb body as a cylinder. Blow through the cylinder to clear any dirt dislodged.

12] Finally reassemble, and reattach to the engine by reversing the steps above.

A couple of other tips.... when cleaning the carb, use a lint free cloth.... any threads or fluff left in the carb will cause havoc. Undertake the whole process in as clean an environment as you can manage... with any fuel system, cleanliness is critical. 

Good luck!

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