What do you feed your engine???

[pfrederi 18,035]

First two pictures from my friends 1075.  Not the damage to the head but the piston is pristine.  second 2 are from my Charger 10 with an HH100.  Piston is beat up head is fine.  Strange... got to wonder what people fed these (and how) engines to do that

[C-101plowerpower 1,606]

mine gets fed 95/98 octane, depents on what i feel like. cant go lower than 95 here tho

[Aldon 4,827]

Non ethanol premium.

 

premium as that's the only non ethanol I can get.

Edited September 14, 2017 by Aldon

[DennisThornton 4,769]

[pfrederi 18,035]

I was being not so clever with the title

...obviously something got inside engine to put those dings in the piston or head.  Not sure why only one side (head or cylinder ) would be damaged.  I had a couple close call over the years dropping air cleaner screws in the carb throat but never had one sucked into the  engine..   What could get in there???

[R. L. Addison 299]

Indigestion! I was given a Wisconsin one time that I was told the governor was blown on.  (1965 - 66)? When I looked into the problem, the governor unit looked O.K., so I pulled the head, and the head and piston were pitted just like the pictures you show, (except worse) but nothing in the combustion chamber. Removed carburater & found throttle plate & screws missing. Don't think the engine was run too long like that, or it would have blown the lower end I would think, but there were no missing pieces to be found anywhere. The only thing I could figure was it all went out through the exhaust. Piston showed no damage except  for the visual pits so I put rings in it and ground the valves & it ran very well. I've been trying to remember where I got the carb. parts, but have no idea today.

Edited September 15, 2017 by R. L. Addison

[stevasaurus 22,939]

Paul, I'm looking at these pictures and 1 thing stands out.  If you had something in the chamber making dents, you would have a mirror image of the dents in both the piston and the head.  It is not there.  The other thing that comes to mind (in my very limited experience tearing apart engines) is that most of any damage is toward the back of the engine chamber.  Call it the air in the tires, if you put a level on the engine block it would be a little lower in the back.   The question I would like to ask...how often do these horses get used??...how long do they set??  Is it possible that certain caustic acids in the gas...sitting in the cylinder for a period of time...soften the metal, and then when you use them the heat from running the engine actually aids in the caustic process??   The valve tops look great...nothing was bouncing around in there...I think you are looking at erosion...then heat...then erosion...then heat.  No way anything in the chamber can go anywhere...except under a valve and it would be in that chamber.  Just thinking and trying to interpret the pictures.    Remember...the piston is probably some aluminum alloy...the rest is cast iron....you knew that.

There is some exhaust leakage in the 3rd picture...you also knew that. 

[stevasaurus 22,939]

To answer your original question...I use SeaFoam and 87 octane gas...I think it has 10% ethanol.  I swear by SeaFoam...that stuff is great on a pizza.  I use it in the gas I keep for the horses...I will put a can in the tank of my truck or the wife's car if I think it is not running quite right.  Wife's car is a 2002...my truck is a 2014.  I have not just torn apart an engine to see what it looks like...the 1st one broke the paddle on the end of the piston rod...the 2nd one was just smoking a lot when I bought it (knowing that I was going to get into that one).  I think that the SeaFoam does what it says it will do.  It takes care of moisture in the gas, it is a stabilizer, and it is a cleaner in carbs (in the horses) and in the jets of automatic injection (in my vehicles).  I have had 2 year old gas that still smells like gas and starts right up.

   Is this stuff eating away at my piston??  I really do not know.  I do know that I have not drained out any bad gas in 10 years.  The Chicago area does not have any gas without ethanol in it for a 100 mile radius.  Ramble, ramble, ramble...sorry Paul...one of those days. 

 

Bottom line...I do not think you had anything metallic in there causing those marks.

[pfrederi 18,035]

I am going to clean up the Techy head tomorrow and see if there are any marks under the carbon.  I do not know the history of either engine. I am thinking you must be on to something about caustics.  if it was a solid object there should be a corresponding mark in both the aluminum piston and aluminum head...wouldn't there Be???.  But if it was a caustic why the marks only on the head of the Kohler 10 hp??? 

[stevasaurus 22,939]

I really do not know...with out knowing how long anything set and the frequency of use and how long you are talking about (30 to 40 years age)...it is very hard to say.  It is just that I do not think it looks like anything was in there causing dents.  I wonder if I could E-Mail those pictures to my engine guy to look at and see what he has to say about it.  He was a Kohler dealer...bet he has handled a few Tecumsehs in his life time.  What do you think?? 

Spoiler

 

[pfrederi 18,035]

I will clean the techy head and get better focused pic tomorrow.. Appreciate it.  I agree eventually if there was something hard i there it would have to get out past the valves and they are in good shape in both engines...

[Jerry77 1,218]

30 minutes ago, stevasaurus said:

SeaFoam and 87 octane gas

My choice too - non ethanol gas is not available in my area...seafoam keeps everything running fine...

[953 nut 56,306]

1 hour ago, stevasaurus said:

Is it possible that certain caustic acids in the gas...sitting in the cylinder for a period of time...soften the metal

Caustic Soda (sodium hydroxide) eats aluminum. You may have some additives that the oil company uses that condenses in the engine which has a high enough PH to cause this.     

PS; acid is PH less than 7 and caustic is above 7.

[N3PUY 1,031]

My guess ..... referring to the first pics .... steel throttle or choke plate screw.  Screw got in there and bounced around.  Maybe the piston was then replaced or the head could be off another engine.  

 

[Shynon 7,474]

My thoughts on this are carbon buildup coming loose before it exits. I have seen carbon buildup chew away the top of the piston. Also a butterfly screw imprint on the piston and head.  91 octane non ethanol

Edited September 15, 2017 by Shynon

[ztnoo 2,298]

I thought this might be a good topic to interject the search information to the question of where to find ethanol free fuel.

I know its been listed before.....I may have given the link, but can't find the post now.

 

Search for locations by state:

https://www.pure-gas.org/

 

 

[KC9KAS 4,741]

18 hours ago, stevasaurus said:

 Is it possible that certain caustic acids in the gas...

Not trying to be a smart ass, but caustic and acid are actually opposites. Both are corrosive.

 

I do agree that if something solid (screw or metal) got in the combustion chamber, it would have to show damage to both the head & piston.

A GT service shop owner told me that "ethanol is not you friend" as far as small engines are concerned. More than likely ethanol in all it's glory is the culprit!

It is odd that 1 engine has head damage, and the other has piston damage!

[BOB ELLISON 2,981]

My son had a yamaha motorcycle in the 1998 and I pulled off the head and it had the pitting also. So I honed the cylinder and installed a new rings and piston .

After 6 months I had to pull the engine (thinking he was very hard on it ) and it was pitted also.

I did some resurch and found this article  it is about the 2 cycle engine. I don't know it it would pertain to a 4 cycle.

If you have a 2/stroke,

 

(Be sure to look at the top of the piston. If it looks like a rat has been chewing on it watch out. It means that the bearings in the bottom end are starting to go. If you put in a new piston it will just be ruined as more bits of bearing shed by the lower crank and rod bearings. The cure? Rebuild the bottom end.)

 

I've seen this before I just don't know how it happens 

 

http://www.dansmc.com/pistons.htm

Just my 

 

[stevasaurus 22,939]

I called my engine guy (who used to be a Kohler dealer) and asked him about all this.  He said this is common in Kohlers and small engines.  The heat is more toward the back of the engine because of the lack of cooling fins on the back side of the engine...that is why the pitting shows up on the back side of the piston.   K181s, K161s, and such did not show this as much because they did not have the heat that the 10 hp engines and up have.   As to why it appears on the head or on the piston...could be how the tractor was stored and how it was used.  Was the horse just used in the winter...just used in the summer...how many thousand hours it has...or hundreds...climate where is was used...etc.  He would still like to see Paul's pictures.  One thing he did say...Kohlers were doing this before ethanol gas. 

[GREYGHOST 65]

ALL of my outdoor equipment get 110/130 octane av gas. Not one drop of that corn fuel. 

Just a couple of questions here. Were any of these engines running in an extended rich fuel air ratio? How old was the oil in each engine, and how clean was it? Were the engine cooling fins clear, or plugged? How is the engine timing?  One thought Im having is detonation. Excessive dirty oil can cause heat build up, and carbon deposits. To rich of a mixture can cause both detonation and heat build up along with added carbon deposits from that unburned fuel. If the engine isn't getting the proper cooling that can also cause pre ignition with added heat. I'm just wondering if any of this may be a reason for the damage noted. I borescoped my 312 a couple of weeks ago after it had been operated with a mixture of Stodard Solovent & Gas. I wish I could have taken pictures to show everyone. But the valves, piston, head,& cylinder wall looked very clean for a 1300+hour engine. I also use Seafoam, but my Meathead Son in Law doesn't. Since I had loaned her to him to use. My Mistake.

[pfrederi 18,035]

23 hours ago, BOB ELLISON said:

My son had a yamaha motorcycle in the 1998 and I pulled off the head and it had the pitting also. So I honed the cylinder and installed a new rings and piston .

After 6 months I had to pull the engine (thinking he was very hard on it ) and it was pitted also.

I did some resurch and found this article  it is about the 2 cycle engine. I don't know it it would pertain to a 4 cycle.

If you have a 2/stroke,

 

(Be sure to look at the top of the piston. If it looks like a rat has been chewing on it watch out. It means that the bearings in the bottom end are starting to go. If you put in a new piston it will just be ruined as more bits of bearing shed by the lower crank and rod bearings. The cure? Rebuild the bottom end.)

 

I've seen this before I just don't know how it happens 

 

http://www.dansmc.com/pistons.htm

Just my 

 

I think that happens only in 2 cycle engines.  There are two sets of slots near the bottom of  the cylinder. One opens into the crankcase..  That is where the fuel oil air mix enters the cylinder (and exhaust gases exit  out the other)

[Digger 66 3,488]

I have to add my opinon as I have before in these threads :

 

Don't put anything in your fuel tank but GASOLINE .

Pure , non-oxygenated gasoline of the correct octane rating for your compression ratio .

Products claiming to be a "fuel injector cleaner" or "upper cylinder lubricant" are ( in my opinion ) complete nonsense .

Ever pour gasoline on a dirty item to clean it ? Works pretty good huh ?

I'll bet it does the same thing in your fuel system without any help .

As for the "upper cylinder lubricant " fantasy ... How can something that has been exploded in a combustion chamber lubricate ...anything .

All these products do ( and again this is my own opinion ) is make carbon deposits that stick between ring lands and to the tops on pistons / valve faces ( and yes may get caught in a valve seat ) .

 

 

 

[stevasaurus 22,939]

@Digger 66  Your thoughts and opinions are always welcome and valued here as far as I am concerned.  You are very likely right also. 

[GREYGHOST 65]

I guess I should have added this. My Meat Head Son in Law has had Temporary ownership of my 312-8 for several years. He doesn't take care of anything he has. MY MISTAKE, anyway he filled a partially empty fuel tank with STODARD SOLOVENT. He thought that the 5 gal Jerry can had gas in it, WRONG. Then he calls me and tells me that the engine won't crank. You might look in the Electrical Section for what I ended up with a Engine Won't Crank. I won't fill this thread up with all that. As for fuel additives, each to their own. 

Brent

[stevasaurus 22,939]

I tend to agree with Digger on what he is saying...but I know that I have had my vehicles start to run  "not right" (you know when that is)...added a can of Sea Foam and filled the tank and things ran great.  Injectors do get sticky for some reason.  I also know when I was cleaning the carbs on the K181 and if I soaked it in gas or if I used a can of carb cleaner...the carb cleaner won every time.

   This is not the thread to start a discussion on additives and their value...let's stick to Paul's thread and try to figure out what happened, and maybe we could start a thread and discussion on additives. 

 

   Paul, I sent your pictures to my engine guy today with an explanation of what we all were thinking.  Will let everyone know what he says.    Great talking with you today.

 

Brent...what a riot...I think I would like to have a beer or 12 with you.