1984 Yamaha XT600 Carburetor Overhaul Part 2

August 01, 2015 admin user 1 comment

Last post on the Carburetor overhaul for this Yamaha XT600 finished with dis-assembly underway.

If we were to summarise carburetor overhauling it would be;

  • Remove carburetor(s) from chassis
  • Disassemble
  • Clean
  • Inspect
  • Fit overhaul kit
  • Reassemble
  • Tune
  • Re-install in chassis
  • Balance

This sounds complex but is well within the scope of most committed home mechanics.

With dis-assembly of the carburetor main body completed we will commence the cleaning process and then move on to inspection.

Here are the Carb body and main components in the ultrasonic cleaner prior to the clean cycle.

 

Ultra Bath 

 

After about 5 minutes the cleaning solution is already quite cloudy, all that crud came from the carburetors...

 

Dirty Water 

 

And here is the cleaned carburetor body. Seriously, how good does this look? 30 years old...

 

 

Below are all the cleaned parts ready for inspection & assembly. We prefer this channeled plastic as it holds the smaller parts.

A T-shirt on a wooden bench works well too. A steel bench top means you have to be pretty careful with these softer alloys and small parts.

 

 

This is why a good overhaul kit is required before the rebuild...Gaskets, fibre or rubber, work harden and perish.

Notice how flattened the old rubber gasket was. Even if it wasn't broken this couldn't be reused.

 

The rubber grease isn't just to aid the seal, it also assists in positioning and retaining the gasket during reassembly.

Treat yourself to a tube. You will wonder how you ever got by without some...

 

The cleaning process isn't complete until you have blown out all the passages and orifices with compressed air. Jets and emulsion tubes too.

 

 

Inspect your components carefully after cleaning and before reassembly. 

In this case the slide and needle are in great nick for a 30 year old. A worn slide or bent or worn needle will make the carb almost impossible to tune.

Note we have the needle height here set to stock. This bike has stock air filter, muffler, jetting, and lives at sea level. Stock needle height required.

 

 

 

Look at the pilot jet, this has copped some heavy handed use around the blade driver slot. Brass is softer than steel so the right size blade is a good idea.

Note also the stock jetting stamp. Always worth checking, you just never know what the last guy did...

 

 

 

That is it for this post, the rebuild, tune and reinstall will be covered in the next post.

 

 

Comments

Martijn February 21, 2016

Good read, I'm in the process of rebuilding mij SRX carb (same as the XT). When will you continue this blog?
Oh and how did you remove the brass seat of the air cut off valve from the body? I got a new one in the rebuild kit, but I can't work out how to remove it without damaging the housing?

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