Decoke engines

[alan]

Hi All

Does anybody have any experience on decoking engines with a spray or other liquid. I would be interested to know if it works or could cause any harm to the engine (or pilot). Any brand names would also be helpful.

[Microwave]

Alan,

I have used Quicksilver Powertune many times on my 582 and I am very happy with the results. You just spray it into the carbs while the engine is running and it does the dirty work for you. You have to run the engine up after it stands (preferably overnight) to blow out all the dirt that has been dislodged during the stand.

I used to painstakingly take off the heads of my previous engine and physically remove the dirt with oven cleaner and a scourer. Wow, what a lousy job and it was no more effective than the use of powertune.

Give it a try.

[kb]

eh, micro, so you "just spray it into the carbs, and let it stand??? wow, sounds helluva easy. why has no-one told us this in the past ( at the airfield I mean)

[alan]

Thanks Micro
Where does one find this stuff, I assume from the name it's a Mercury outboard product so would you get it at a boat shop

[Aviation Engines]

I find that far too often people over react about decoking. I have heard from many Rotax owners that they have cleaned only the piston crown and called that a decoke. More important is the cleaning of the ring grooves. Most oils nowadays are so advanced that the deposits created has been reduced tremendously compared to oils from 10 years ago, this includes the cheaper miniral based oils. Therefore the need to decoke your engine has also been reduced.

I recommend that at every 100 hours, remove the exhaust manifold and thorugh the port you will be able to inspect the rings and piston crown. Push on the rings with your finger or a blunt object to check if they are not sticking. The piston crown will always have deposits on it, you will have to use your discretion here and decide if you need to strip and decoke. You will be quite surprised to see that a decoke might not be necessary.

My concern with using a spray or additive through the carbs is that we do not know how it will react with the internal components, seals and o-rings. It is possible that the Quicksilver Powertune leaves no side effects, but has Microwave opened the engine and inspected it?

What i'm trying to tell everyone is that you shouldn't get all excited about decoking until you've removed the exhaust manifold and inspected it. In my experience I have found that in most cases a decoke has become necessary at around 200 hours.

Thats my 5 cents worth...............

Niren
Aviation Engines.

[Aquillaguy]

I have just recently started to use Wynns Compression Stabiliser in a Spray format. R30 odd from any Midas.

Before and after inspection through the manefold was overwhelmingly good.

Gunked up rings where loose and shiny again....



Andreas

[IFLYHI]

I have just recently started to use Wynns Compression Stabiliser in a Spray format. R30 odd from any Midas.

How do you apply the spray

[BIG-G]

My experiance with these de-coke agents is all good. I honestly feel you do more damage to a perfectly running engine, constantly opening it up.
On my 1500 hours on two stroke engines I used Quicksilver two stroke oil which has the same TCW3 rating that Rotax recomends. Quicksilver also produces a product called Power Tune. This decoking agent is sprayed directly into the carbs of a running engine. Microwave has expained the rest.

My last 582 engine was first opened at 700 hours. No carbon anywhere. Rings were loose, manifold and exhaust clean. Niren at Aviation Engines even asked me who had honed my barrels. There was no wear.

Most boating shops will keep Quicksilver and Power Tune.