Engine breakdown, recommendation anyone?

[adrian101]

well yesterday i decided to take the head and cylinder jug off my motor. Which i learnt from the good man Al.Fisherman's thread and photo's of "Breaking down a China HT engine".

I done this to check if the engine is correctly lubed and also check for major wear but it was all good. Alot of people say clean the top of the piston where the spark plug hits (carbon buildup) when getting the chance to breakdown the engine.

my question is: how to do so without scratching/damaging the surface? whats the best way to get the carbon buildup off, without hitting it with a blow torch?

and also when putting the cylinder jug back over the piston is it okay to lighty lube the piston and piston sleeve with 2 stock oil?

 

[hammer5312]

well...Not having done it.....but having been inside of other two strokes.....
If you don't remove the jug then be careful not to scratch the walls using some sand paper or 3M scotchbrite pads

If you pull the jug then use the same sandpaper or scotchbrite pads, but make sure to put some rags to keep debris from falling down inside the engine....

Also yeah you can oil the piston, prolly won't need it.....just make sure of the ring placement when you re-assemble...

 

[V 35]

Soak carbon with Brake Cleaner, let evaporate off, than wet with spray lube. Let lube soak in several hours. Use an old Credit Card to scrape carbon. * Avoid shiny and scratches. Shiny tends to run hot, better to leave a stain of carbon, than risk a scratch.

Yes ! Oil up the rings before loading ring compressor, be sure bottom ring is flush * not cocked * before driving down.

 

[MikeJ]

I'd like to politely disagree with Hammer's advice. Do NOT use physical abrasives like sandpaper or Scotchbrite pads. Keep in mind that these products shed particles of abrasives; that is their design. If you cannot positively guarantee that loose particles do not get into your engine, then go ahead. But from my automobile engine building experience, particles can embed themselves into cylinder walls, pistons rings, etc. And remain abrasive. They are just not good for any engine, as emphatically emphasized by a couple of engine building authorities. (Names escape me at this time.)

 

[adrian101]

I'd like to politely disagree with Hammer's advice. Do NOT use physical abrasives like sandpaper or Scotchbrite pads. Keep in mind that these products shed particles of abrasives; that is their design. If you cannot positively guarantee that loose particles do not get into your engine, then go ahead. But from my automobile engine building experience, particles can embed themselves into cylinder walls, pistons rings, etc. And remain abrasive. They are just not good for any engine, as emphatically emphasized by a couple of engine building authorities. (Names escape me at this time.)

lol i forget when i posted this thread but i have already broke down my engine. I left the piston in fuel/gas for 3 days. When i took it out the carbon just slide off the top of the piston with a soft rag

Oiled her back up and boom she was perfect again..

 

[HeadSmess]

chrome plated cylinder, leave em alone...

soft black carbon is too much oil/rich. it should look like a good sparkplug in a healthy engine...tan. and then there will be minimal deposits.

always apply a squirt of 2strokers in the BARREL before assembly. not the piston. try to keep it out of the rings. its not actually doing any favours when its filling in the space behind a ring, preventing the ring from doing its job...