Decarbonizing alloy heads

[JDGQ]

I've stripped down my CR250 two stroke for a new piston and rings and want to give the cylinder a real good scrub to get out all the built up carbon around the power valve and exhaust port.

I've started cleaning it with carby clean but some of it is really built up and in some pretty tight areas at that. so i'm considering my options for products that may be out there to clean the surfaces i want to clean without effecting the actual cylinder bore surface where the piston runs?
Either that or if anyone knows of an engine shop on the northside of brisbane that would be happy for me to dunk the whole thing in their acid bath for a couple of hours!

Any advice or suggestions greatly appreciated

[turbo gu]

buy a couple of tins of Subaru upper engine cleaner and soak it with that!

[JDGQ]

hmmm good point, that shit is the bomb!

although it does work better when the engines hot, just means i'll have to scrub harder. should probably go buy some cheap tooth brushes or pip cleaners to get right in there.

[tehekho]

although it does work better when the engines hot,

Stick it in the oven for a while?

[MICK77]

buy a couple of tins of Subaru upper engine cleaner and soak it with that!

^^ This.

I swear by it.

Cheers,

Micko

[JDGQ]

although it does work better when the engines hot,

Stick it in the oven for a while?

yeah after awhile i kinda thought that myself but i dunno how the missus would appreciate having the engine in the oven hehehe

[Clanky]

although it does work better when the engines hot,

Stick it in the oven for a while?

yeah after awhile i kinda thought that myself but i dunno how the missus would appreciate having the engine in the oven hehehe

Probably better than an oily axle in the freezer and a bearing in the oven before owning a bearing press!
Wow, how angry can a mum get when the food smells and tastes of gear oil

[JDGQ]

Ok so lucky for me the wife didnt get home till late on Friday night so i was able to warm up the cylinder in the oven at about 90 degree's or so (less than the 100 mark anyway) for about 30-45 mins.

took it out in the garage and hit the crucial spots with the subaru brand upper cylinder cleaner and man did it do a good job! Be warned thou, when sprayed onto a rather hot surface it does vaporize and has a ball tearer of a smell, if you think it rips carbon off metal surfaces just imagine what it can do to your nose hairs and lungs!

All in all was mostly a success, the only downside is that when the oven is heated up now it has a slight burnt 2 stroke oil smell to it and not in a good way....

[date]

Not necessarily carbon from the combustion cahmber (although it did celan thisup as well), years ago I had a Range Rover which I bought from a friend. It had been meticulously serviced ie oil changes every 10000 km. The problem was that it took about 18 months to get the 10000 km up. Most of teh running was at slow suburban speeds and cold. End result - oil galleries gunked up so that the rocker gear was getting virtually no oil.

A friend of mine saw the heads and got a 20 litre drum and over half filled it with water. Then he threw in a few large handfuls of OMO washing powder, dunked the head in and boiled it up over a large gas ring. After about 30 minutes, we removed the head and put the other end in and repeated the rpocess. Result - Brand new head - very shite and briny. All carbon gone from teh combustion chamber and more importantly in my case, the oil passages totally clear. There was no noticeable etching or pitting of the aluminium surfaces.

I did a lot of miles with the Rangie and changed the oil a lot more frequently and never had any more sludging problems after that.