D.I.Y Decoke???

[psg]

Hi All
I just wanted to know who does a decoke themselves and who takes it to a specialist? Many people as well as my instructor insist that only a proffesional can do this? I have rebuilt many motors in my time over the years and still do some work for a company that make sports cars. I know that many people are not capable or willing to do this themselves but if you can why not? I also worry about who does the work at the specialist anyway? I know that most are very good but who actually does the work? The only problem i can see is that not doing the specific motor everyday you dont get the experience that some people have on that specific motor. Im not trying to save money because once you have bought all the necessary bits and special tools its more expensive anyway.

Regards
Sacha

[Morph]

Which motor?

I did my old 503 myself and it's quite easy to do if you have some technical ability

Here is my post and one by Rudi Greyling on the 503

http://microlighters.co.za/viewtopic.php?t=1851

http://microlighters.co.za/viewtopic.php?t=2057

[Duck Rogers]

Do it yourself. If you have the ability and the tools, it's a piece of cake.
Rotax have some special "tools" for the job. Look around on the net for these and make them yourself. They're nothing more than jigs to align the cylinders on re-assembly. Everything else is straight forward.

[psg]

Hi all
Thanks for the advice and links very good indeed.

Regards
Sacha

[Big-D]

Duck

What are your thoughts on a chemical decoke

Quicksilver powertune - Spray into carbs and the black stuff comes out

Thoughts?

D

[Miskiet]

I tried a famous bike supplier's product - 300 hrs later my top rings were still loose but both bottom rings on the 503 were stuck. Lots of carbon on the pistons. I even sprayed the stuff on the pistons after I stripped the engine - they didn't make the carbon soft or any easier to remove (maybe it only works when it is burned inside the engine?)

I reckon the best bet is to spend lots of effort getting your mixture (EGT's) right - You should then have the least amount of carbon build up possible. From what I've seen on my engine a de-coke every 300hrs is not a bad idea.

[Duck Rogers]

Duck

What are your thoughts on a chemical decoke

Quicksilver powertune - Spray into carbs and the black stuff comes out

Thoughts?

D

Short and sweet.....Doesn't work

[Pumba]

Sacha / Dave

There is a product on the market called "Seafoam". You can Google it on the net, I don't know if anyone sells it in SA. It is supposed to work as follows: One cyliner at a time, you unscrew a sparkplug, rotate the engine until the piston just covers the inlet and exhaust ports, then spray in a fairly large quantity of this foam on top of the piston. Screw the plug back in, and rotate the engine until this piston is at TDC. You let it sit like this for a while to let the foam do its thing. The foam is forced past the rings and is supposed to work into the ring grooves and soften / dissolve any built up carbon. After each cylinder is treated this way, you start the engine, and in a huge black cloud of smoke, you are supposed to be rid of any carbon build up.

Does it work? I have never used it, but some of the Jetski and Seadoo guys think that it does.

Yamaha makes a similar product, intended for use on their outboard engines. (I think this product is supposed to be sprayed through the carb with the engine running.) On these engines, it does not normally hurt or pose the same threat as when your noise maker on your ML goes quiet, and maybe its OK for those applications.

I would still recommend stripping, cleaning and inspecting everything every so often, rather than take a chance on some chemical product.

Stripping and assembling a 503 is really not difficult. There are a few things you need to do very carefully and in exact accordance with the manufacturers recommendations. Some excellent threads on the forum you can follow as well.

Barry

[DieselFan]

But whats riskier? Doing the foam thingie twice or opening up your motor and risking not putting certain parts back in the correct places with correct torque settings etc. esp for the average microlight pilot?

So not in terms of a 100% thorough decoke but for the reliability of engine? Would a 70% decoke be better than a 100% one with a mechanic lacking full knowledge

[psg]

Hi
Im not really a fan of all these additives and remedys for motors i just believe that you need to open them up as per rotax.I want to see inside as well as a look and feel of the bearings. I have a 462 has anyone got any other advice lots of info on the 403 about i see. Will keep you posted.


Sacha

[Aerosan]

Agree with psg and Duck- open it up and do it right. Rotax would have had an expensive chemical remedy by now. Besides you can also check the insides