Has anyone use Dawn Power Dissolver? It is supposed to remove the dark brown buildup of glow fuel residue that ends up staining the engine. I have read where you can remove it by soaking the enging in Prestone in a crock pot but if this works it would be much better.

As far as i know,you submerge the engine in auto engine antifreez, in a old cooking pot outside on a camping stove of some sorts,overnight on real low temp if you please! The motor will look as close to new as you can get, to my knowledge anyway.[8D]

I've never worried much about a bit of varnish on my engines. I'm also a firm believer in the concept of if it ain't broke, don't fix it. If I have an engine that's running good, the last thing I want to do is something to mess it up. I've seen way too many instances where someone decided to take apart a perfectly good engine and the thing never ran right again. Once it's running well, I wouldn't do anything that would mess with the fit, including removing varnish from the piston.

But anyway, having a nice clean engine is important to some people. I haven't heard of anyone using Dawn, but the crockpot method seems fairly common. It's important to get the right type of antifreeze. It's also critical that you NOT do this inside or in a location where children or animals could get to it. The antifreeze, including the fumes, is toxic. Also, the crockpot will absorb some of the antifreeze, so it should never be used again for food.

I totally agree with Chuck. IMHO an engine with lots of varnish on it means that it's been taken care of for it's life. That varnish tells me that the engine has been ran nice and rich in it's life and should be a good running engine. On the other hand, an engine that's used and is all nice and clean make me wonder what it's trying to hide!!

As was said above, never EVER use the crock pot of cooking food again. Use this outside because the vapors given off are toxic so you should have plenty of ventilation. Take apart the engine enough to remove any rubber parts, plastic parts, and any gaskets. Place the engine parts in the crock pot and pour enough antifreeze in to cover the parts. Turn the crock pot on low and let them sit in the heated antifreeze. How long will depend on how much stuff you have on your engines. Check periodically to see if the crud is loosening up. Use an old toothbrush (once again, don't use it for your teeth ever again) to see if it's loosening up. Once the crud starts breaking up then use the brush to remove it from your engine. Once you have the engine clean rinse away the antifreeze and then put a light coat of after run oil on the internal parts of the engine. You can can re-assemble the engine.

One point, you have to use the green anti-freeze. The environmentally safe stuff won't work for this.

Hope this helps

Ken

I'm confused,as always..
Is this varnish buildup on the outside of the engine or inside ?
If its on the the outside has anyone one try to use Easyoff Oven Spray.
I use it to get rid of the heavy wood resin buildup on my saw blades
and router bits when I do wood work. I know it works on wood resin,
maybe it will work on the varnish. If somebody trys it,spray it on,let soak,
clean with a tooth brush.

I'm fairly sure that's the one I used to use years ago while it was still available here in Australia but for some reason it's been taken off the shelves here. There were two types, one for steel and one for aluminium, don't use the one for steel. The other one though was remarkably good for just cleaning up the outside of the engine. No dismantling needed, I just blocked the carb and exhaust port then gave it a quick spray and let it foam up for maybe 30 seconds before giving it a quick scrub with a toothbrush. Rinse and scrub under running water and dry.

I would not use Easy Off. The stuff that I have seen in the grocery store WILL ATTACK THE ALUMINUM on/in the engine.

2 items you can use for the OUTSIDE OF THE ENGINE are:

Carburator cleaner (several applications will be needed)

Acetone

Make sure you use them outside AND NO SMOKING.

Any of the oven cleaners will turn the aluminum on your engine a very dull grey color.

Even the aluminum safe oven cleaners will attack the engine if left on them for several days.

Once the engine is grey, it is that way forever.

If you use antifreeze, do not boil it. You only want it hot. If you boil your engine in antifreeze, it will discolor the engine eventually