Engine/exhaust decoke

[simon1221]

1) Can i do this myself?

2) If not then how much at the garage?

3) What is it?
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DNA50 (sorry) ->> TZR125l >> GPZ500S

[stinkwheel]

It is the act of removing any sooty black carbon deposits from your engine, the crown of the piston and the powervalve (if fitted). These are the result of burning oil in with the fuel in a 2-stroke.

Exhaust: 2 ways, if the baffle in the end of the exhaust system is removeable, take it out, pour petrol over it and set it on fire. Once it has cooled, remove any remaining carbon using a wire brush.

Other way is to remove the whole exhaust ststem, fit a bung in one end and fill it up with caustic soda solution (goggles, gloves!). Leave it to soak for 1/2 an hour then empty it out and rinse through with clean water before refitting.

Piston: Drain the coolant. Take the cylinder head off, set piston to top-dead centre. Scrape the worst of the carbon off with an old screwdriver then clean up with some emery paper. Be carefull not to mark the actual metal. Remove the loose debris with a hoover or some blue-tak. Refit cylinder head using a new gasket. Refill coolant

Powervalve: Never done it myself.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[mchaggis]

NaOH(aq) + C(s) -> ?
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I must not be a troll...
Mmmm, Guinness
Discovering the delights of Hammerite and a 3/4" brush.

[stinkwheel]

Don't think it is a reaction as such, there are unburned hydrocarbons there too sticking the carbon together. I thought it was more of a 'soap' type hydrophobic thing allowing the carbon/oil mush to be suspended in the water.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.