Does my piston look okay?

[Mozenrath]

Out of curiosity, I removed the head from my engine to take a look inside.

The piston seems to have this dark brown, almost black patchy layer on top. The spot isn't sticky or anything, in fact it's quite smooth. I would remove it, but I'm not sure whether I should or if it's even possible.

Note, I've only been running this motor for about 2 weeks. I followed the erroneous Chinese instructions which said to use a 16:1 fuel to oil mix, but I've decided to just use up the last half-gallon I have of that mix since my spark plug contacts have a cocoa brown color.

 

[Greg58]

The top of the piston looks o/k , most will have the disscoloration you see. What would be a problem is carbon build up, carbon over time can cause vibration problems. What does the cylinder look like with the piston a bottom?

 

[Mozenrath]

The top of the piston looks o/k , most will have the disscoloration you see. What would be a problem is carbon build up, carbon over time can cause vibration problems. What does the cylinder look like with the piston a bottom?

I don't have a picture, but last I looked the cylinder seemed pretty clean. I'll take a look again, but I don't remember seeing any build-up.

 

[ddesens]

I think greg58 is asking if you noticed any score lines on the cylinder wall. Different quality oils and fuels, carb tuning and how you drive can change the look of the deposits in your engine. You can run some "sea foam" in your gas once in a while to keep the build up down. It can be found at your local auto parts store. To me your piston head looks "normal". Just my 2 cents.--Dave

 

[buck0]

I would remove it, but I'm not sure whether I should or if it's even possible.

I never thought of using sea foam on a 2 stroke.

I removed that brown crap off the top of my piston with the dremel and have atleast 2 wire brush attachments available as it will wear them down.

 

[Greg58]

Sea foam is a great fuel additive, I use it in our dirt bikes all the time. I have also started using a ethenol treatment for small engines in my lawn mowers,string trimer and blower. Here in the metro Atlanta area all gasoline has ethenol in it.

 

[Al.Fisherman]

Sea Foam is used mostly in 2 cycle, although it will work in any combustion engine. As stated, it rids of excess carbon in the combustion chamber. This is most noticed in 2 cycle engines because of the burning of oil mix. This is the most used product (other engine builders have basically the same product sold under the manufacture name) in the marine applications. The only additives I use is Sea Foam, and Techron (max strength, once a year) in my gas burner Yukon. Diesels have a different product I use.

 

[Mozenrath]

I think greg58 is asking if you noticed any score lines on the cylinder wall. Different quality oils and fuels, carb tuning and how you drive can change the look of the deposits in your engine. You can run some "sea foam" in your gas once in a while to keep the build up down. It can be found at your local auto parts store. To me your piston head looks "normal". Just my 2 cents.--Dave

I did find a single score line. I'll look into getting sea foam and perhaps getting better quality oil(as opposed to weed eater oil).

 

[Greg58]

As long as it is not a scratch you can feel it should be o/k. On some pistons there is a small pin in the ring groove to holds the rings in place or to keep them from turning, that could be what you are seeing.

 

[Mozenrath]

I think there are some scratches. Most of them I can't feel, but there's one that I can. But the engine seems to be running well for the time being.

Note that I was originally running on a 16:1 mix, but my spark plug was a cocoa color so I decided to run through the rest of that gallon and now it's running on a 24:1 mix.

 

[Mozenrath]

BUMP

Sorry, but could anybody tell me whether or not my cylinder is okay before I put the jug back on my engine?

The pictures are on the previous page.

 

[DuctTapedGoat]

You're good to go - though it wouldn't hurt to polish things up while its off.