This is Bad Right?
 

I purchased this engine used, have been using penzz 40:1....My engine has great compression , but kinda lacks in RPM compared to others 80cc engines....i get about 5950 rpm with a 26x10 Xoar

So i took the engine apart and noticed this(see pics) ill never buy another used gas engine again, unless i can see it in person

RE: This is Bad Right?
 

Doesn't look bad to me, it's a well used 3W80 that needs a clean up, no big. Check the ring end gap, if it's more than about .008" get some new ones.</p>

RE: This is Bad Right?
 

.018" is old age for a 3w. .004" to .015" is within specs. Looks like someone liked castor or never realized when they had stuck the rings and kept happily running along. Jody, better tell him how to check end gaps accurately.

If it was mine I might consider rustling up a new set of rings and clean the carbon out of the ring grooves. If I didn't get new rings I'd still do the ring grooves and add ring cleaning to the list, cleaning the carbon off the inside of the ring with an Xacto blade and use some 2000g sand paper and a little oil to clean the carbon off the top of the ring. I'd lay the sandpaper flat on a table, lay the top of the ring flat on the paper, and very lightly slide the ring on the oiled paper in a circular motion until only the carbon was removed from the ring. Don't do the bottom of the ring. I wouldn't worry about the deposits on the piston skirt but I might take some grey Scotchbrite pad to the top and remove what I could.

This is done quite frequently and has a tendency of returning an engine to it's original performance level or better if the rings weren't cooked off and lost tension. I don't think you bought a bad engine at all, just one needing a little TLC before it can be all it can be.

RE: This is Bad Right?
 

thanks for the adivce...heraing this from you guys makes me feel better, and i still have a potentially better motor


*edit....i will order a set of rings from www.aircraftinternational.com

RE: This is Bad Right?
 

If the gap is anywhere near tolerance on the second ring, I would get a new Frank Bowman ring for the top groove and run the original in the second. It will definitely restore the power. His rings are really good.

[email protected]

Home Phone: 505-327-0696

Home Address: View map 1211 N Allen Ave
Farmington,, NM 87401

Notes: Great Rings for any engine

AV8TOR

RE: This is Bad Right?
 

Put a wire wheel on a dremel and go around the ring grooves and the top of the piston. Quick and simple. Carbon is no big deal. Make sure the sparkplug is clean or just go ahead and install a new one gapped at .020, thats the main thing. Actually, that engine is destroyed, I'll give you 10 bucks for it....

RE: This is Bad Right?
 

Please do not do that. If you're buying new rings break one of the old ones in half and file the end to a sharp angle and carefully scrape out the ring groove after using some solvent to loosen the burned on carbon.

The wrong type of wire wheel leaves steel fragments in an aluminum piston. Steel retains more heat than aluminum. Gets sorta ugly when the imbedded steel starts melting little pits in the piston. The wrong type of wire wheel also removes a lot of aluminum from a piston. Sucks when the rings are flopping around in the ring groove and the corners of the piston that make the squish function are gone.

Total time to go through your engine and get it done right will be about an hour....

RE: This is Bad Right?
 

I glass bead blasted a piston once and there was steel particles in the blast media.

I then had a steel impregnated piston. I learned to clean out the bead blaster and use new beads before doing some none steel important item. But I never did a piston in there again.

I try to do it like Pat says.

RE: This is Bad Right?
 

http://www.rcuniverse.com/forum/js/f.../msn/50_50.gifhttp://www.rcuniverse.com/forum/js/f...humbs_down.gif

RE: This is Bad Right?
 

what type of solvent do you recommend?

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I use mineral spirits for general parts cleaning, for hard baked on Amso... I mean carbon, I use a marine product that is sold for outboards called "Engine Tuner". It comes in a bomb can and is intended to be sprayed into the engine while running to remove carbon. I let parts soak in it over night and most of the carbon will wipe off the next day.

RE: This is Bad Right?
 

If the engine is apart any carb cleaner will do. Kerosene loosens things up pretty good too, but you have to soak them in it.

RE: This is Bad Right?
 

the rings should be here tuesday or wednesday...im looking forward to working on my motor. Thanks for all the help

Looks like ill be soaking piston in kerosene or mineral spirits and "scrub it with non metallic scour pad

Kerosene is the same thing as lamp oil?

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Hello. Is there any advantage, for our use in cleaning engines, of K1 Kerosene? It is actually more available around here, being used for space heaters and such. Thanks

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The only disadvantage I can think of is that it stinks

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No, lamp oil will not do what you want. Lamp oil today is much closer to oil than solvent.

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Anyone here ever used the automotive anti freeze trick on a castor oil stained glow engine? If you aren't in too big a hurry, a small cheap crock pot with enough anti freeze in it to cover the parts, cooked for a day. I found that process incredibly effective. Wondering how that process might work in a situation like this - including the Amsoil messes? Thinking about it, not sure how it might affect anodizing?

RE: This is Bad Right?
 

My wife got all pi$$ed off when I tried that. It was our only crock pot...

RE: This is Bad Right?
 

Wow. I hear that. Someone was nice enough to inform me I'd never get the taste out, and it's obviously nasty stuff for your internals. They suggested a cheapie from Wally World or similar. That tip saved me from the wrath of my resident finance minister. I wouldn't have ever considered that possibility. I ended up with a little one that holds maybe 2 qts? Perfect size for anything I'm likely to be soaking, and thinking it was about 9.00

Sure works nice in the end though. I had some older engines laying around that I though were goners. Rough bearings, frozen carb barrels, the whole gamut. Time and trouble to completely diassemble, clean, oil, and reassemble saved all but one using NO parts! The last one needed a new set of bearings.

The active ingredient contained in the anti freeze that's doing the cleaning has to be a mild acid or something? Whatever, it works nice. Recommend the process to anyone capable of taking an engine apart and reassembling. The engine will be spotless when you're done. Some really stubborn areas may need some help from a stiff bristeled nylon scrub brush, but that's about it.

In the case of the engine above, my thought would be to cook the cylinder, piston and rings only?
FWIW

Edit: Last thought. Don't be cooking anything that might melt or deform - like gaskets and rubber/plastic carb parts! Nylon (or whatever) ball races seem to take it OK though....

RE: This is Bad Right?
 

Why din't you all just go to any car parts store and get a gallon of carb cleaner, as TOM sugested. Have used this several times on carboned engines with sucess. May take 7-10 days to remove all the carbon, however you will be using a product that is designed for the job. Years ago the carb cleaner was formulated differently, and would clean aluminum in a few hours. If you have access to the old formula, then faster removable will be possible.
Cheers

RE: This is Bad Right?
 

I've got the good old stuff, I wouldn't soak modern pistons in it, metallurgy today is not what it was 30 years ago, not that it's bad it's just you never know what might happen. The stuff has ruined more than a couple parts in the past, it will remove anodizing and all the hair from your nostrils.

RE: This is Bad Right?
 

Stewed anodized parts in glycol based anti freeze in the crock pot and doesnt effect the anodizing except make it all shiny and clean.

RE: This is Bad Right?
 

Take care to NOT let the antifreeze boil, as the liquid AND fumes are toxic. Look up the MSDS (material safety data sheet) for Prestone or Peak and it will tell you what not to do and what happens if you go ahead and do it anyway. My crock pot has a medium and high setting on the dial. The high setting will make the mix boil! (don't ask me how I know) Also make sure all the parts are completely submerged or you will get a line at the solution level on the part. And don't ever use the crock pot for food again!

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Another caveat. The AF mix in the crockpot will turn some ENYA crankcases and other cast parts dark gray (again, don't ask me how I know). This may be a function of how long you cook the parts, but, overnight overcooked my Enya. It was not damaged but the color was dark.

RE: This is Bad Right?
 

Some engine manufacturers use a chemical rinse process to brighten the part after the casting process. Looks better to users so they sell faster. Likely the AF stripped away the layer that had been chemically modified in appearance.